BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
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/*
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* brin_pageops.c
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* Page-handling routines for BRIN indexes
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*
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2018-01-03 05:30:12 +01:00
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* Portions Copyright (c) 1996-2018, PostgreSQL Global Development Group
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BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* IDENTIFICATION
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* src/backend/access/brin/brin_pageops.c
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*/
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#include "postgres.h"
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#include "access/brin_pageops.h"
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#include "access/brin_page.h"
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#include "access/brin_revmap.h"
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#include "access/brin_xlog.h"
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#include "access/xloginsert.h"
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#include "miscadmin.h"
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#include "storage/bufmgr.h"
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#include "storage/freespace.h"
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#include "storage/lmgr.h"
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#include "storage/smgr.h"
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#include "utils/rel.h"
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2015-10-27 22:17:55 +01:00
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/*
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* Maximum size of an entry in a BRIN_PAGETYPE_REGULAR page. We can tolerate
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* a single item per page, unlike other index AMs.
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*/
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#define BrinMaxItemSize \
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MAXALIGN_DOWN(BLCKSZ - \
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(MAXALIGN(SizeOfPageHeaderData + \
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sizeof(ItemIdData)) + \
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MAXALIGN(sizeof(BrinSpecialSpace))))
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BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
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static Buffer brin_getinsertbuffer(Relation irel, Buffer oldbuf, Size itemsz,
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Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
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bool *extended);
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BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
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static Size br_page_get_freespace(Page page);
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Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
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static void brin_initialize_empty_new_buffer(Relation idxrel, Buffer buffer);
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BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
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/*
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* Update tuple origtup (size origsz), located in offset oldoff of buffer
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* oldbuf, to newtup (size newsz) as summary tuple for the page range starting
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* at heapBlk. oldbuf must not be locked on entry, and is not locked at exit.
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*
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* If samepage is true, attempt to put the new tuple in the same page, but if
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* there's no room, use some other one.
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*
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* If the update is successful, return true; the revmap is updated to point to
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* the new tuple. If the update is not done for whatever reason, return false.
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* Caller may retry the update if this happens.
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*/
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bool
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brin_doupdate(Relation idxrel, BlockNumber pagesPerRange,
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BrinRevmap *revmap, BlockNumber heapBlk,
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Buffer oldbuf, OffsetNumber oldoff,
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const BrinTuple *origtup, Size origsz,
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const BrinTuple *newtup, Size newsz,
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bool samepage)
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{
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Page oldpage;
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ItemId oldlp;
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BrinTuple *oldtup;
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Size oldsz;
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Buffer newbuf;
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Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
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BlockNumber newblk = InvalidBlockNumber;
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Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
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bool extended;
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BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
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Fix valgrind's "unaddressable bytes" whining about BRIN code.
brin_form_tuple calculated an exact tuple size, then palloc'd and
filled just that much. Later, brin_doinsert or brin_doupdate would
MAXALIGN the tuple size and tell PageAddItem that that was the size
of the tuple to insert. If the original tuple size wasn't a multiple
of MAXALIGN, the net result would be that PageAddItem would memcpy
a few more bytes than the palloc request had been for.
AFAICS, this is totally harmless in the real world: the error is a
read overrun not a write overrun, and palloc would certainly have
rounded the request up to a MAXALIGN multiple internally, so there's
no chance of the memcpy fetching off the end of memory. Valgrind,
however, is picky to the byte level not the MAXALIGN level.
Fix it by pushing the MAXALIGN step back to brin_form_tuple. (The other
possible source of tuples in this code, brin_form_placeholder_tuple,
was already producing a MAXALIGN'd result.)
In passing, be a bit more paranoid about internal allocations in
brin_form_tuple.
2015-05-26 03:56:19 +02:00
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Assert(newsz == MAXALIGN(newsz));
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
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|
2015-10-27 22:17:55 +01:00
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|
/* If the item is oversized, don't bother. */
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if (newsz > BrinMaxItemSize)
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{
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ereport(ERROR,
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(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
|
Phase 3 of pgindent updates.
Don't move parenthesized lines to the left, even if that means they
flow past the right margin.
By default, BSD indent lines up statement continuation lines that are
within parentheses so that they start just to the right of the preceding
left parenthesis. However, traditionally, if that resulted in the
continuation line extending to the right of the desired right margin,
then indent would push it left just far enough to not overrun the margin,
if it could do so without making the continuation line start to the left of
the current statement indent. That makes for a weird mix of indentations
unless one has been completely rigid about never violating the 80-column
limit.
This behavior has been pretty universally panned by Postgres developers.
Hence, disable it with indent's new -lpl switch, so that parenthesized
lines are always lined up with the preceding left paren.
This patch is much less interesting than the first round of indent
changes, but also bulkier, so I thought it best to separate the effects.
Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org
Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 21:35:54 +02:00
|
|
|
errmsg("index row size %zu exceeds maximum %zu for index \"%s\"",
|
|
|
|
newsz, BrinMaxItemSize, RelationGetRelationName(idxrel))));
|
2015-10-27 22:17:55 +01:00
|
|
|
return false; /* keep compiler quiet */
|
|
|
|
}
|
|
|
|
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
/* make sure the revmap is long enough to contain the entry we need */
|
|
|
|
brinRevmapExtend(revmap, heapBlk);
|
|
|
|
|
|
|
|
if (!samepage)
|
|
|
|
{
|
|
|
|
/* need a page on which to put the item */
|
|
|
|
newbuf = brin_getinsertbuffer(idxrel, oldbuf, newsz, &extended);
|
|
|
|
if (!BufferIsValid(newbuf))
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
{
|
|
|
|
Assert(!extended);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
return false;
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
}
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Note: it's possible (though unlikely) that the returned newbuf is
|
|
|
|
* the same as oldbuf, if brin_getinsertbuffer determined that the old
|
|
|
|
* buffer does in fact have enough space.
|
|
|
|
*/
|
|
|
|
if (newbuf == oldbuf)
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
{
|
|
|
|
Assert(!extended);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
newbuf = InvalidBuffer;
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
}
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
else
|
|
|
|
newblk = BufferGetBlockNumber(newbuf);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
}
|
|
|
|
else
|
|
|
|
{
|
|
|
|
LockBuffer(oldbuf, BUFFER_LOCK_EXCLUSIVE);
|
|
|
|
newbuf = InvalidBuffer;
|
2015-08-13 05:12:07 +02:00
|
|
|
extended = false;
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
}
|
2016-04-20 15:31:19 +02:00
|
|
|
oldpage = BufferGetPage(oldbuf);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
oldlp = PageGetItemId(oldpage, oldoff);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Check that the old tuple wasn't updated concurrently: it might have
|
2017-11-02 17:54:22 +01:00
|
|
|
* moved someplace else entirely, and for that matter the whole page
|
|
|
|
* might've become a revmap page. Note that in the first two cases
|
|
|
|
* checked here, the "oldlp" we just calculated is garbage; but
|
|
|
|
* PageGetItemId() is simple enough that it was safe to do that
|
|
|
|
* calculation anyway.
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
*/
|
2017-11-02 17:54:22 +01:00
|
|
|
if (!BRIN_IS_REGULAR_PAGE(oldpage) ||
|
|
|
|
oldoff > PageGetMaxOffsetNumber(oldpage) ||
|
|
|
|
!ItemIdIsNormal(oldlp))
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
{
|
|
|
|
LockBuffer(oldbuf, BUFFER_LOCK_UNLOCK);
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
|
|
|
|
/*
|
|
|
|
* If this happens, and the new buffer was obtained by extending the
|
|
|
|
* relation, then we need to ensure we don't leave it uninitialized or
|
|
|
|
* forget about it.
|
|
|
|
*/
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
if (BufferIsValid(newbuf))
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
{
|
|
|
|
if (extended)
|
|
|
|
brin_initialize_empty_new_buffer(idxrel, newbuf);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
UnlockReleaseBuffer(newbuf);
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
if (extended)
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
FreeSpaceMapVacuumRange(idxrel, newblk, newblk + 1);
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
}
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
return false;
|
|
|
|
}
|
|
|
|
|
|
|
|
oldsz = ItemIdGetLength(oldlp);
|
|
|
|
oldtup = (BrinTuple *) PageGetItem(oldpage, oldlp);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* ... or it might have been updated in place to different contents.
|
|
|
|
*/
|
|
|
|
if (!brin_tuples_equal(oldtup, oldsz, origtup, origsz))
|
|
|
|
{
|
|
|
|
LockBuffer(oldbuf, BUFFER_LOCK_UNLOCK);
|
|
|
|
if (BufferIsValid(newbuf))
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
{
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
/* As above, initialize and record new page if we got one */
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
if (extended)
|
|
|
|
brin_initialize_empty_new_buffer(idxrel, newbuf);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
UnlockReleaseBuffer(newbuf);
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
if (extended)
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
FreeSpaceMapVacuumRange(idxrel, newblk, newblk + 1);
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
}
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
return false;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Great, the old tuple is intact. We can proceed with the update.
|
|
|
|
*
|
|
|
|
* If there's enough room in the old page for the new tuple, replace it.
|
|
|
|
*
|
|
|
|
* Note that there might now be enough space on the page even though the
|
|
|
|
* caller told us there isn't, if a concurrent update moved another tuple
|
|
|
|
* elsewhere or replaced a tuple with a smaller one.
|
|
|
|
*/
|
2015-03-10 16:26:34 +01:00
|
|
|
if (((BrinPageFlags(oldpage) & BRIN_EVACUATE_PAGE) == 0) &&
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
brin_can_do_samepage_update(oldbuf, origsz, newsz))
|
|
|
|
{
|
|
|
|
START_CRIT_SECTION();
|
Invent PageIndexTupleOverwrite, and teach BRIN and GiST to use it.
PageIndexTupleOverwrite performs approximately the same function as
PageIndexTupleDelete (or PageIndexDeleteNoCompact) followed by PageAddItem
targeting the same item pointer offset. But in the case where the new
tuple is the same size as the old, it avoids shuffling other data around on
the page, because the new tuple is placed where the old one was rather than
being appended to the end of the page. This has been shown to provide a
substantial speedup for some GiST use-cases.
Also, this change allows some API simplifications: we can get rid of
the rather klugy and error-prone PAI_ALLOW_FAR_OFFSET flag for
PageAddItemExtended, since that was used only to cover a corner case
for BRIN that's better expressed by using PageIndexTupleOverwrite.
Note that this patch causes a rather subtle WAL incompatibility: the
physical page content change represented by certain WAL records is now
different than it was before, because while the tuples have the same
itempointer line numbers, the tuples themselves are in different places.
I have not bumped the WAL version number because I think it doesn't matter
unless you are trying to do bitwise comparisons of original and replayed
pages, and in any case we're early in a devel cycle and there will probably
be more WAL changes before v10 gets out the door.
There is probably room to make use of PageIndexTupleOverwrite in SP-GiST
and GIN too, but that is left for a future patch.
Andrey Borodin, reviewed by Anastasia Lubennikova, whacked around a bit
by me
Discussion: <CAJEAwVGQjGGOj6mMSgMwGvtFd5Kwe6VFAxY=uEPZWMDjzbn4VQ@mail.gmail.com>
2016-09-10 00:02:24 +02:00
|
|
|
if (!PageIndexTupleOverwrite(oldpage, oldoff, (Item) newtup, newsz))
|
|
|
|
elog(ERROR, "failed to replace BRIN tuple");
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
MarkBufferDirty(oldbuf);
|
|
|
|
|
|
|
|
/* XLOG stuff */
|
|
|
|
if (RelationNeedsWAL(idxrel))
|
|
|
|
{
|
|
|
|
xl_brin_samepage_update xlrec;
|
|
|
|
XLogRecPtr recptr;
|
|
|
|
uint8 info = XLOG_BRIN_SAMEPAGE_UPDATE;
|
|
|
|
|
Revamp the WAL record format.
Each WAL record now carries information about the modified relation and
block(s) in a standardized format. That makes it easier to write tools that
need that information, like pg_rewind, prefetching the blocks to speed up
recovery, etc.
There's a whole new API for building WAL records, replacing the XLogRecData
chains used previously. The new API consists of XLogRegister* functions,
which are called for each buffer and chunk of data that is added to the
record. The new API also gives more control over when a full-page image is
written, by passing flags to the XLogRegisterBuffer function.
This also simplifies the XLogReadBufferForRedo() calls. The function can dig
the relation and block number from the WAL record, so they no longer need to
be passed as arguments.
For the convenience of redo routines, XLogReader now disects each WAL record
after reading it, copying the main data part and the per-block data into
MAXALIGNed buffers. The data chunks are not aligned within the WAL record,
but the redo routines can assume that the pointers returned by XLogRecGet*
functions are. Redo routines are now passed the XLogReaderState, which
contains the record in the already-disected format, instead of the plain
XLogRecord.
The new record format also makes the fixed size XLogRecord header smaller,
by removing the xl_len field. The length of the "main data" portion is now
stored at the end of the WAL record, and there's a separate header after
XLogRecord for it. The alignment padding at the end of XLogRecord is also
removed. This compansates for the fact that the new format would otherwise
be more bulky than the old format.
Reviewed by Andres Freund, Amit Kapila, Michael Paquier, Alvaro Herrera,
Fujii Masao.
2014-11-20 16:56:26 +01:00
|
|
|
xlrec.offnum = oldoff;
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
|
Revamp the WAL record format.
Each WAL record now carries information about the modified relation and
block(s) in a standardized format. That makes it easier to write tools that
need that information, like pg_rewind, prefetching the blocks to speed up
recovery, etc.
There's a whole new API for building WAL records, replacing the XLogRecData
chains used previously. The new API consists of XLogRegister* functions,
which are called for each buffer and chunk of data that is added to the
record. The new API also gives more control over when a full-page image is
written, by passing flags to the XLogRegisterBuffer function.
This also simplifies the XLogReadBufferForRedo() calls. The function can dig
the relation and block number from the WAL record, so they no longer need to
be passed as arguments.
For the convenience of redo routines, XLogReader now disects each WAL record
after reading it, copying the main data part and the per-block data into
MAXALIGNed buffers. The data chunks are not aligned within the WAL record,
but the redo routines can assume that the pointers returned by XLogRecGet*
functions are. Redo routines are now passed the XLogReaderState, which
contains the record in the already-disected format, instead of the plain
XLogRecord.
The new record format also makes the fixed size XLogRecord header smaller,
by removing the xl_len field. The length of the "main data" portion is now
stored at the end of the WAL record, and there's a separate header after
XLogRecord for it. The alignment padding at the end of XLogRecord is also
removed. This compansates for the fact that the new format would otherwise
be more bulky than the old format.
Reviewed by Andres Freund, Amit Kapila, Michael Paquier, Alvaro Herrera,
Fujii Masao.
2014-11-20 16:56:26 +01:00
|
|
|
XLogBeginInsert();
|
|
|
|
XLogRegisterData((char *) &xlrec, SizeOfBrinSamepageUpdate);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
|
Revamp the WAL record format.
Each WAL record now carries information about the modified relation and
block(s) in a standardized format. That makes it easier to write tools that
need that information, like pg_rewind, prefetching the blocks to speed up
recovery, etc.
There's a whole new API for building WAL records, replacing the XLogRecData
chains used previously. The new API consists of XLogRegister* functions,
which are called for each buffer and chunk of data that is added to the
record. The new API also gives more control over when a full-page image is
written, by passing flags to the XLogRegisterBuffer function.
This also simplifies the XLogReadBufferForRedo() calls. The function can dig
the relation and block number from the WAL record, so they no longer need to
be passed as arguments.
For the convenience of redo routines, XLogReader now disects each WAL record
after reading it, copying the main data part and the per-block data into
MAXALIGNed buffers. The data chunks are not aligned within the WAL record,
but the redo routines can assume that the pointers returned by XLogRecGet*
functions are. Redo routines are now passed the XLogReaderState, which
contains the record in the already-disected format, instead of the plain
XLogRecord.
The new record format also makes the fixed size XLogRecord header smaller,
by removing the xl_len field. The length of the "main data" portion is now
stored at the end of the WAL record, and there's a separate header after
XLogRecord for it. The alignment padding at the end of XLogRecord is also
removed. This compansates for the fact that the new format would otherwise
be more bulky than the old format.
Reviewed by Andres Freund, Amit Kapila, Michael Paquier, Alvaro Herrera,
Fujii Masao.
2014-11-20 16:56:26 +01:00
|
|
|
XLogRegisterBuffer(0, oldbuf, REGBUF_STANDARD);
|
|
|
|
XLogRegisterBufData(0, (char *) newtup, newsz);
|
|
|
|
|
|
|
|
recptr = XLogInsert(RM_BRIN_ID, info);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
|
|
|
|
PageSetLSN(oldpage, recptr);
|
|
|
|
}
|
|
|
|
|
|
|
|
END_CRIT_SECTION();
|
|
|
|
|
|
|
|
LockBuffer(oldbuf, BUFFER_LOCK_UNLOCK);
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
if (BufferIsValid(newbuf))
|
|
|
|
{
|
|
|
|
/* As above, initialize and record new page if we got one */
|
|
|
|
if (extended)
|
|
|
|
brin_initialize_empty_new_buffer(idxrel, newbuf);
|
|
|
|
UnlockReleaseBuffer(newbuf);
|
|
|
|
if (extended)
|
|
|
|
FreeSpaceMapVacuumRange(idxrel, newblk, newblk + 1);
|
|
|
|
}
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
return true;
|
|
|
|
}
|
|
|
|
else if (newbuf == InvalidBuffer)
|
|
|
|
{
|
|
|
|
/*
|
|
|
|
* Not enough space, but caller said that there was. Tell them to
|
|
|
|
* start over.
|
|
|
|
*/
|
|
|
|
LockBuffer(oldbuf, BUFFER_LOCK_UNLOCK);
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
else
|
|
|
|
{
|
|
|
|
/*
|
|
|
|
* Not enough free space on the oldpage. Put the new tuple on the new
|
|
|
|
* page, and update the revmap.
|
|
|
|
*/
|
2016-04-20 15:31:19 +02:00
|
|
|
Page newpage = BufferGetPage(newbuf);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
Buffer revmapbuf;
|
|
|
|
ItemPointerData newtid;
|
|
|
|
OffsetNumber newoff;
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
Size freespace = 0;
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
|
|
|
|
revmapbuf = brinLockRevmapPageForUpdate(revmap, heapBlk);
|
|
|
|
|
|
|
|
START_CRIT_SECTION();
|
|
|
|
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
/*
|
|
|
|
* We need to initialize the page if it's newly obtained. Note we
|
|
|
|
* will WAL-log the initialization as part of the update, so we don't
|
|
|
|
* need to do that here.
|
|
|
|
*/
|
|
|
|
if (extended)
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
brin_page_init(newpage, BRIN_PAGETYPE_REGULAR);
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
|
2016-09-10 01:00:59 +02:00
|
|
|
PageIndexTupleDeleteNoCompact(oldpage, oldoff);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
newoff = PageAddItem(newpage, (Item) newtup, newsz,
|
|
|
|
InvalidOffsetNumber, false, false);
|
|
|
|
if (newoff == InvalidOffsetNumber)
|
|
|
|
elog(ERROR, "failed to add BRIN tuple to new page");
|
|
|
|
MarkBufferDirty(oldbuf);
|
|
|
|
MarkBufferDirty(newbuf);
|
|
|
|
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
/* needed to update FSM below */
|
|
|
|
if (extended)
|
|
|
|
freespace = br_page_get_freespace(newpage);
|
|
|
|
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
ItemPointerSet(&newtid, newblk, newoff);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
brinSetHeapBlockItemptr(revmapbuf, pagesPerRange, heapBlk, newtid);
|
|
|
|
MarkBufferDirty(revmapbuf);
|
|
|
|
|
|
|
|
/* XLOG stuff */
|
|
|
|
if (RelationNeedsWAL(idxrel))
|
|
|
|
{
|
|
|
|
xl_brin_update xlrec;
|
|
|
|
XLogRecPtr recptr;
|
|
|
|
uint8 info;
|
|
|
|
|
|
|
|
info = XLOG_BRIN_UPDATE | (extended ? XLOG_BRIN_INIT_PAGE : 0);
|
|
|
|
|
Revamp the WAL record format.
Each WAL record now carries information about the modified relation and
block(s) in a standardized format. That makes it easier to write tools that
need that information, like pg_rewind, prefetching the blocks to speed up
recovery, etc.
There's a whole new API for building WAL records, replacing the XLogRecData
chains used previously. The new API consists of XLogRegister* functions,
which are called for each buffer and chunk of data that is added to the
record. The new API also gives more control over when a full-page image is
written, by passing flags to the XLogRegisterBuffer function.
This also simplifies the XLogReadBufferForRedo() calls. The function can dig
the relation and block number from the WAL record, so they no longer need to
be passed as arguments.
For the convenience of redo routines, XLogReader now disects each WAL record
after reading it, copying the main data part and the per-block data into
MAXALIGNed buffers. The data chunks are not aligned within the WAL record,
but the redo routines can assume that the pointers returned by XLogRecGet*
functions are. Redo routines are now passed the XLogReaderState, which
contains the record in the already-disected format, instead of the plain
XLogRecord.
The new record format also makes the fixed size XLogRecord header smaller,
by removing the xl_len field. The length of the "main data" portion is now
stored at the end of the WAL record, and there's a separate header after
XLogRecord for it. The alignment padding at the end of XLogRecord is also
removed. This compansates for the fact that the new format would otherwise
be more bulky than the old format.
Reviewed by Andres Freund, Amit Kapila, Michael Paquier, Alvaro Herrera,
Fujii Masao.
2014-11-20 16:56:26 +01:00
|
|
|
xlrec.insert.offnum = newoff;
|
2014-11-08 04:31:03 +01:00
|
|
|
xlrec.insert.heapBlk = heapBlk;
|
|
|
|
xlrec.insert.pagesPerRange = pagesPerRange;
|
Revamp the WAL record format.
Each WAL record now carries information about the modified relation and
block(s) in a standardized format. That makes it easier to write tools that
need that information, like pg_rewind, prefetching the blocks to speed up
recovery, etc.
There's a whole new API for building WAL records, replacing the XLogRecData
chains used previously. The new API consists of XLogRegister* functions,
which are called for each buffer and chunk of data that is added to the
record. The new API also gives more control over when a full-page image is
written, by passing flags to the XLogRegisterBuffer function.
This also simplifies the XLogReadBufferForRedo() calls. The function can dig
the relation and block number from the WAL record, so they no longer need to
be passed as arguments.
For the convenience of redo routines, XLogReader now disects each WAL record
after reading it, copying the main data part and the per-block data into
MAXALIGNed buffers. The data chunks are not aligned within the WAL record,
but the redo routines can assume that the pointers returned by XLogRecGet*
functions are. Redo routines are now passed the XLogReaderState, which
contains the record in the already-disected format, instead of the plain
XLogRecord.
The new record format also makes the fixed size XLogRecord header smaller,
by removing the xl_len field. The length of the "main data" portion is now
stored at the end of the WAL record, and there's a separate header after
XLogRecord for it. The alignment padding at the end of XLogRecord is also
removed. This compansates for the fact that the new format would otherwise
be more bulky than the old format.
Reviewed by Andres Freund, Amit Kapila, Michael Paquier, Alvaro Herrera,
Fujii Masao.
2014-11-20 16:56:26 +01:00
|
|
|
xlrec.oldOffnum = oldoff;
|
|
|
|
|
|
|
|
XLogBeginInsert();
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
|
Revamp the WAL record format.
Each WAL record now carries information about the modified relation and
block(s) in a standardized format. That makes it easier to write tools that
need that information, like pg_rewind, prefetching the blocks to speed up
recovery, etc.
There's a whole new API for building WAL records, replacing the XLogRecData
chains used previously. The new API consists of XLogRegister* functions,
which are called for each buffer and chunk of data that is added to the
record. The new API also gives more control over when a full-page image is
written, by passing flags to the XLogRegisterBuffer function.
This also simplifies the XLogReadBufferForRedo() calls. The function can dig
the relation and block number from the WAL record, so they no longer need to
be passed as arguments.
For the convenience of redo routines, XLogReader now disects each WAL record
after reading it, copying the main data part and the per-block data into
MAXALIGNed buffers. The data chunks are not aligned within the WAL record,
but the redo routines can assume that the pointers returned by XLogRecGet*
functions are. Redo routines are now passed the XLogReaderState, which
contains the record in the already-disected format, instead of the plain
XLogRecord.
The new record format also makes the fixed size XLogRecord header smaller,
by removing the xl_len field. The length of the "main data" portion is now
stored at the end of the WAL record, and there's a separate header after
XLogRecord for it. The alignment padding at the end of XLogRecord is also
removed. This compansates for the fact that the new format would otherwise
be more bulky than the old format.
Reviewed by Andres Freund, Amit Kapila, Michael Paquier, Alvaro Herrera,
Fujii Masao.
2014-11-20 16:56:26 +01:00
|
|
|
/* new page */
|
|
|
|
XLogRegisterData((char *) &xlrec, SizeOfBrinUpdate);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
|
Revamp the WAL record format.
Each WAL record now carries information about the modified relation and
block(s) in a standardized format. That makes it easier to write tools that
need that information, like pg_rewind, prefetching the blocks to speed up
recovery, etc.
There's a whole new API for building WAL records, replacing the XLogRecData
chains used previously. The new API consists of XLogRegister* functions,
which are called for each buffer and chunk of data that is added to the
record. The new API also gives more control over when a full-page image is
written, by passing flags to the XLogRegisterBuffer function.
This also simplifies the XLogReadBufferForRedo() calls. The function can dig
the relation and block number from the WAL record, so they no longer need to
be passed as arguments.
For the convenience of redo routines, XLogReader now disects each WAL record
after reading it, copying the main data part and the per-block data into
MAXALIGNed buffers. The data chunks are not aligned within the WAL record,
but the redo routines can assume that the pointers returned by XLogRecGet*
functions are. Redo routines are now passed the XLogReaderState, which
contains the record in the already-disected format, instead of the plain
XLogRecord.
The new record format also makes the fixed size XLogRecord header smaller,
by removing the xl_len field. The length of the "main data" portion is now
stored at the end of the WAL record, and there's a separate header after
XLogRecord for it. The alignment padding at the end of XLogRecord is also
removed. This compansates for the fact that the new format would otherwise
be more bulky than the old format.
Reviewed by Andres Freund, Amit Kapila, Michael Paquier, Alvaro Herrera,
Fujii Masao.
2014-11-20 16:56:26 +01:00
|
|
|
XLogRegisterBuffer(0, newbuf, REGBUF_STANDARD | (extended ? REGBUF_WILL_INIT : 0));
|
|
|
|
XLogRegisterBufData(0, (char *) newtup, newsz);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
|
Revamp the WAL record format.
Each WAL record now carries information about the modified relation and
block(s) in a standardized format. That makes it easier to write tools that
need that information, like pg_rewind, prefetching the blocks to speed up
recovery, etc.
There's a whole new API for building WAL records, replacing the XLogRecData
chains used previously. The new API consists of XLogRegister* functions,
which are called for each buffer and chunk of data that is added to the
record. The new API also gives more control over when a full-page image is
written, by passing flags to the XLogRegisterBuffer function.
This also simplifies the XLogReadBufferForRedo() calls. The function can dig
the relation and block number from the WAL record, so they no longer need to
be passed as arguments.
For the convenience of redo routines, XLogReader now disects each WAL record
after reading it, copying the main data part and the per-block data into
MAXALIGNed buffers. The data chunks are not aligned within the WAL record,
but the redo routines can assume that the pointers returned by XLogRecGet*
functions are. Redo routines are now passed the XLogReaderState, which
contains the record in the already-disected format, instead of the plain
XLogRecord.
The new record format also makes the fixed size XLogRecord header smaller,
by removing the xl_len field. The length of the "main data" portion is now
stored at the end of the WAL record, and there's a separate header after
XLogRecord for it. The alignment padding at the end of XLogRecord is also
removed. This compansates for the fact that the new format would otherwise
be more bulky than the old format.
Reviewed by Andres Freund, Amit Kapila, Michael Paquier, Alvaro Herrera,
Fujii Masao.
2014-11-20 16:56:26 +01:00
|
|
|
/* revmap page */
|
2017-01-09 22:19:29 +01:00
|
|
|
XLogRegisterBuffer(1, revmapbuf, 0);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
|
Revamp the WAL record format.
Each WAL record now carries information about the modified relation and
block(s) in a standardized format. That makes it easier to write tools that
need that information, like pg_rewind, prefetching the blocks to speed up
recovery, etc.
There's a whole new API for building WAL records, replacing the XLogRecData
chains used previously. The new API consists of XLogRegister* functions,
which are called for each buffer and chunk of data that is added to the
record. The new API also gives more control over when a full-page image is
written, by passing flags to the XLogRegisterBuffer function.
This also simplifies the XLogReadBufferForRedo() calls. The function can dig
the relation and block number from the WAL record, so they no longer need to
be passed as arguments.
For the convenience of redo routines, XLogReader now disects each WAL record
after reading it, copying the main data part and the per-block data into
MAXALIGNed buffers. The data chunks are not aligned within the WAL record,
but the redo routines can assume that the pointers returned by XLogRecGet*
functions are. Redo routines are now passed the XLogReaderState, which
contains the record in the already-disected format, instead of the plain
XLogRecord.
The new record format also makes the fixed size XLogRecord header smaller,
by removing the xl_len field. The length of the "main data" portion is now
stored at the end of the WAL record, and there's a separate header after
XLogRecord for it. The alignment padding at the end of XLogRecord is also
removed. This compansates for the fact that the new format would otherwise
be more bulky than the old format.
Reviewed by Andres Freund, Amit Kapila, Michael Paquier, Alvaro Herrera,
Fujii Masao.
2014-11-20 16:56:26 +01:00
|
|
|
/* old page */
|
|
|
|
XLogRegisterBuffer(2, oldbuf, REGBUF_STANDARD);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
|
Revamp the WAL record format.
Each WAL record now carries information about the modified relation and
block(s) in a standardized format. That makes it easier to write tools that
need that information, like pg_rewind, prefetching the blocks to speed up
recovery, etc.
There's a whole new API for building WAL records, replacing the XLogRecData
chains used previously. The new API consists of XLogRegister* functions,
which are called for each buffer and chunk of data that is added to the
record. The new API also gives more control over when a full-page image is
written, by passing flags to the XLogRegisterBuffer function.
This also simplifies the XLogReadBufferForRedo() calls. The function can dig
the relation and block number from the WAL record, so they no longer need to
be passed as arguments.
For the convenience of redo routines, XLogReader now disects each WAL record
after reading it, copying the main data part and the per-block data into
MAXALIGNed buffers. The data chunks are not aligned within the WAL record,
but the redo routines can assume that the pointers returned by XLogRecGet*
functions are. Redo routines are now passed the XLogReaderState, which
contains the record in the already-disected format, instead of the plain
XLogRecord.
The new record format also makes the fixed size XLogRecord header smaller,
by removing the xl_len field. The length of the "main data" portion is now
stored at the end of the WAL record, and there's a separate header after
XLogRecord for it. The alignment padding at the end of XLogRecord is also
removed. This compansates for the fact that the new format would otherwise
be more bulky than the old format.
Reviewed by Andres Freund, Amit Kapila, Michael Paquier, Alvaro Herrera,
Fujii Masao.
2014-11-20 16:56:26 +01:00
|
|
|
recptr = XLogInsert(RM_BRIN_ID, info);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
|
|
|
|
PageSetLSN(oldpage, recptr);
|
|
|
|
PageSetLSN(newpage, recptr);
|
2016-04-20 15:31:19 +02:00
|
|
|
PageSetLSN(BufferGetPage(revmapbuf), recptr);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
}
|
|
|
|
|
|
|
|
END_CRIT_SECTION();
|
|
|
|
|
|
|
|
LockBuffer(revmapbuf, BUFFER_LOCK_UNLOCK);
|
|
|
|
LockBuffer(oldbuf, BUFFER_LOCK_UNLOCK);
|
|
|
|
UnlockReleaseBuffer(newbuf);
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
|
|
|
|
if (extended)
|
|
|
|
{
|
|
|
|
RecordPageWithFreeSpace(idxrel, newblk, freespace);
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
FreeSpaceMapVacuumRange(idxrel, newblk, newblk + 1);
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
}
|
|
|
|
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
return true;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Return whether brin_doupdate can do a samepage update.
|
|
|
|
*/
|
|
|
|
bool
|
|
|
|
brin_can_do_samepage_update(Buffer buffer, Size origsz, Size newsz)
|
|
|
|
{
|
|
|
|
return
|
|
|
|
((newsz <= origsz) ||
|
2016-04-20 15:31:19 +02:00
|
|
|
PageGetExactFreeSpace(BufferGetPage(buffer)) >= (newsz - origsz));
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Insert an index tuple into the index relation. The revmap is updated to
|
|
|
|
* mark the range containing the given page as pointing to the inserted entry.
|
|
|
|
* A WAL record is written.
|
|
|
|
*
|
|
|
|
* The buffer, if valid, is first checked for free space to insert the new
|
|
|
|
* entry; if there isn't enough, a new buffer is obtained and pinned. No
|
|
|
|
* buffer lock must be held on entry, no buffer lock is held on exit.
|
|
|
|
*
|
|
|
|
* Return value is the offset number where the tuple was inserted.
|
|
|
|
*/
|
|
|
|
OffsetNumber
|
|
|
|
brin_doinsert(Relation idxrel, BlockNumber pagesPerRange,
|
|
|
|
BrinRevmap *revmap, Buffer *buffer, BlockNumber heapBlk,
|
|
|
|
BrinTuple *tup, Size itemsz)
|
|
|
|
{
|
|
|
|
Page page;
|
|
|
|
BlockNumber blk;
|
|
|
|
OffsetNumber off;
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
Size freespace = 0;
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
Buffer revmapbuf;
|
|
|
|
ItemPointerData tid;
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
bool extended;
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
|
Fix valgrind's "unaddressable bytes" whining about BRIN code.
brin_form_tuple calculated an exact tuple size, then palloc'd and
filled just that much. Later, brin_doinsert or brin_doupdate would
MAXALIGN the tuple size and tell PageAddItem that that was the size
of the tuple to insert. If the original tuple size wasn't a multiple
of MAXALIGN, the net result would be that PageAddItem would memcpy
a few more bytes than the palloc request had been for.
AFAICS, this is totally harmless in the real world: the error is a
read overrun not a write overrun, and palloc would certainly have
rounded the request up to a MAXALIGN multiple internally, so there's
no chance of the memcpy fetching off the end of memory. Valgrind,
however, is picky to the byte level not the MAXALIGN level.
Fix it by pushing the MAXALIGN step back to brin_form_tuple. (The other
possible source of tuples in this code, brin_form_placeholder_tuple,
was already producing a MAXALIGN'd result.)
In passing, be a bit more paranoid about internal allocations in
brin_form_tuple.
2015-05-26 03:56:19 +02:00
|
|
|
Assert(itemsz == MAXALIGN(itemsz));
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
|
2015-10-27 22:17:55 +01:00
|
|
|
/* If the item is oversized, don't even bother. */
|
|
|
|
if (itemsz > BrinMaxItemSize)
|
|
|
|
{
|
|
|
|
ereport(ERROR,
|
|
|
|
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
|
Phase 3 of pgindent updates.
Don't move parenthesized lines to the left, even if that means they
flow past the right margin.
By default, BSD indent lines up statement continuation lines that are
within parentheses so that they start just to the right of the preceding
left parenthesis. However, traditionally, if that resulted in the
continuation line extending to the right of the desired right margin,
then indent would push it left just far enough to not overrun the margin,
if it could do so without making the continuation line start to the left of
the current statement indent. That makes for a weird mix of indentations
unless one has been completely rigid about never violating the 80-column
limit.
This behavior has been pretty universally panned by Postgres developers.
Hence, disable it with indent's new -lpl switch, so that parenthesized
lines are always lined up with the preceding left paren.
This patch is much less interesting than the first round of indent
changes, but also bulkier, so I thought it best to separate the effects.
Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org
Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 21:35:54 +02:00
|
|
|
errmsg("index row size %zu exceeds maximum %zu for index \"%s\"",
|
|
|
|
itemsz, BrinMaxItemSize, RelationGetRelationName(idxrel))));
|
Phase 2 of pgindent updates.
Change pg_bsd_indent to follow upstream rules for placement of comments
to the right of code, and remove pgindent hack that caused comments
following #endif to not obey the general rule.
Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using
the published version of pg_bsd_indent, but a hacked-up version that
tried to minimize the amount of movement of comments to the right of
code. The situation of interest is where such a comment has to be
moved to the right of its default placement at column 33 because there's
code there. BSD indent has always moved right in units of tab stops
in such cases --- but in the previous incarnation, indent was working
in 8-space tab stops, while now it knows we use 4-space tabs. So the
net result is that in about half the cases, such comments are placed
one tab stop left of before. This is better all around: it leaves
more room on the line for comment text, and it means that in such
cases the comment uniformly starts at the next 4-space tab stop after
the code, rather than sometimes one and sometimes two tabs after.
Also, ensure that comments following #endif are indented the same
as comments following other preprocessor commands such as #else.
That inconsistency turns out to have been self-inflicted damage
from a poorly-thought-through post-indent "fixup" in pgindent.
This patch is much less interesting than the first round of indent
changes, but also bulkier, so I thought it best to separate the effects.
Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org
Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 21:18:54 +02:00
|
|
|
return InvalidOffsetNumber; /* keep compiler quiet */
|
2015-10-27 22:17:55 +01:00
|
|
|
}
|
|
|
|
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
/* Make sure the revmap is long enough to contain the entry we need */
|
|
|
|
brinRevmapExtend(revmap, heapBlk);
|
|
|
|
|
|
|
|
/*
|
2015-08-13 05:12:07 +02:00
|
|
|
* Acquire lock on buffer supplied by caller, if any. If it doesn't have
|
|
|
|
* enough space, unpin it to obtain a new one below.
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
*/
|
|
|
|
if (BufferIsValid(*buffer))
|
|
|
|
{
|
|
|
|
/*
|
|
|
|
* It's possible that another backend (or ourselves!) extended the
|
|
|
|
* revmap over the page we held a pin on, so we cannot assume that
|
|
|
|
* it's still a regular page.
|
|
|
|
*/
|
|
|
|
LockBuffer(*buffer, BUFFER_LOCK_EXCLUSIVE);
|
2016-04-20 15:31:19 +02:00
|
|
|
if (br_page_get_freespace(BufferGetPage(*buffer)) < itemsz)
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
{
|
|
|
|
UnlockReleaseBuffer(*buffer);
|
|
|
|
*buffer = InvalidBuffer;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2015-08-13 05:12:07 +02:00
|
|
|
/*
|
|
|
|
* If we still don't have a usable buffer, have brin_getinsertbuffer
|
|
|
|
* obtain one for us.
|
|
|
|
*/
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
if (!BufferIsValid(*buffer))
|
|
|
|
{
|
2015-10-27 22:17:55 +01:00
|
|
|
do
|
|
|
|
*buffer = brin_getinsertbuffer(idxrel, InvalidBuffer, itemsz, &extended);
|
|
|
|
while (!BufferIsValid(*buffer));
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
}
|
2015-08-13 05:12:07 +02:00
|
|
|
else
|
|
|
|
extended = false;
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
|
|
|
|
/* Now obtain lock on revmap buffer */
|
|
|
|
revmapbuf = brinLockRevmapPageForUpdate(revmap, heapBlk);
|
|
|
|
|
2016-04-20 15:31:19 +02:00
|
|
|
page = BufferGetPage(*buffer);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
blk = BufferGetBlockNumber(*buffer);
|
|
|
|
|
2015-08-13 05:12:07 +02:00
|
|
|
/* Execute the actual insertion */
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
START_CRIT_SECTION();
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
if (extended)
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
brin_page_init(page, BRIN_PAGETYPE_REGULAR);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
off = PageAddItem(page, (Item) tup, itemsz, InvalidOffsetNumber,
|
|
|
|
false, false);
|
|
|
|
if (off == InvalidOffsetNumber)
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
elog(ERROR, "failed to add BRIN tuple to new page");
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
MarkBufferDirty(*buffer);
|
|
|
|
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
/* needed to update FSM below */
|
|
|
|
if (extended)
|
|
|
|
freespace = br_page_get_freespace(page);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
|
|
|
|
ItemPointerSet(&tid, blk, off);
|
|
|
|
brinSetHeapBlockItemptr(revmapbuf, pagesPerRange, heapBlk, tid);
|
|
|
|
MarkBufferDirty(revmapbuf);
|
|
|
|
|
|
|
|
/* XLOG stuff */
|
|
|
|
if (RelationNeedsWAL(idxrel))
|
|
|
|
{
|
|
|
|
xl_brin_insert xlrec;
|
|
|
|
XLogRecPtr recptr;
|
|
|
|
uint8 info;
|
|
|
|
|
|
|
|
info = XLOG_BRIN_INSERT | (extended ? XLOG_BRIN_INIT_PAGE : 0);
|
|
|
|
xlrec.heapBlk = heapBlk;
|
|
|
|
xlrec.pagesPerRange = pagesPerRange;
|
Revamp the WAL record format.
Each WAL record now carries information about the modified relation and
block(s) in a standardized format. That makes it easier to write tools that
need that information, like pg_rewind, prefetching the blocks to speed up
recovery, etc.
There's a whole new API for building WAL records, replacing the XLogRecData
chains used previously. The new API consists of XLogRegister* functions,
which are called for each buffer and chunk of data that is added to the
record. The new API also gives more control over when a full-page image is
written, by passing flags to the XLogRegisterBuffer function.
This also simplifies the XLogReadBufferForRedo() calls. The function can dig
the relation and block number from the WAL record, so they no longer need to
be passed as arguments.
For the convenience of redo routines, XLogReader now disects each WAL record
after reading it, copying the main data part and the per-block data into
MAXALIGNed buffers. The data chunks are not aligned within the WAL record,
but the redo routines can assume that the pointers returned by XLogRecGet*
functions are. Redo routines are now passed the XLogReaderState, which
contains the record in the already-disected format, instead of the plain
XLogRecord.
The new record format also makes the fixed size XLogRecord header smaller,
by removing the xl_len field. The length of the "main data" portion is now
stored at the end of the WAL record, and there's a separate header after
XLogRecord for it. The alignment padding at the end of XLogRecord is also
removed. This compansates for the fact that the new format would otherwise
be more bulky than the old format.
Reviewed by Andres Freund, Amit Kapila, Michael Paquier, Alvaro Herrera,
Fujii Masao.
2014-11-20 16:56:26 +01:00
|
|
|
xlrec.offnum = off;
|
|
|
|
|
|
|
|
XLogBeginInsert();
|
|
|
|
XLogRegisterData((char *) &xlrec, SizeOfBrinInsert);
|
|
|
|
|
|
|
|
XLogRegisterBuffer(0, *buffer, REGBUF_STANDARD | (extended ? REGBUF_WILL_INIT : 0));
|
|
|
|
XLogRegisterBufData(0, (char *) tup, itemsz);
|
|
|
|
|
|
|
|
XLogRegisterBuffer(1, revmapbuf, 0);
|
|
|
|
|
|
|
|
recptr = XLogInsert(RM_BRIN_ID, info);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
|
|
|
|
PageSetLSN(page, recptr);
|
2016-04-20 15:31:19 +02:00
|
|
|
PageSetLSN(BufferGetPage(revmapbuf), recptr);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
}
|
|
|
|
|
|
|
|
END_CRIT_SECTION();
|
|
|
|
|
|
|
|
/* Tuple is firmly on buffer; we can release our locks */
|
|
|
|
LockBuffer(*buffer, BUFFER_LOCK_UNLOCK);
|
|
|
|
LockBuffer(revmapbuf, BUFFER_LOCK_UNLOCK);
|
|
|
|
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
BRIN_elog((DEBUG2, "inserted tuple (%u,%u) for range starting at %u",
|
|
|
|
blk, off, heapBlk));
|
|
|
|
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
if (extended)
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
{
|
|
|
|
RecordPageWithFreeSpace(idxrel, blk, freespace);
|
|
|
|
FreeSpaceMapVacuumRange(idxrel, blk, blk + 1);
|
|
|
|
}
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
|
|
|
|
return off;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Initialize a page with the given type.
|
|
|
|
*
|
|
|
|
* Caller is responsible for marking it dirty, as appropriate.
|
|
|
|
*/
|
|
|
|
void
|
|
|
|
brin_page_init(Page page, uint16 type)
|
|
|
|
{
|
|
|
|
PageInit(page, BLCKSZ, sizeof(BrinSpecialSpace));
|
|
|
|
|
2015-03-10 16:26:34 +01:00
|
|
|
BrinPageType(page) = type;
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
Set the metapage's pd_lower correctly in brin, gin, and spgist indexes.
Previously, these index types left the pd_lower field set to the default
SizeOfPageHeaderData, which is really a lie because it ought to point past
whatever space is being used for metadata. The coding accidentally failed
to fail because we never told xlog.c that the metapage is of standard
format --- but that's not very good, because it impedes WAL consistency
checking, and in some cases prevents compression of full-page images.
To fix, ensure that we set pd_lower correctly, not only when creating a
metapage but whenever we write it out (these apparently redundant steps are
needed to cope with pg_upgrade'd indexes that don't yet contain the right
value). This allows telling xlog.c that the page is of standard format.
The WAL consistency check mask functions are made to mask only if pd_lower
appears valid, which I think is likely unnecessary complication, since
any metapage appearing in a v11 WAL stream should contain valid pd_lower.
But it doesn't cost much to be paranoid.
Amit Langote, reviewed by Michael Paquier and Amit Kapila
Discussion: https://postgr.es/m/0d273805-0e9e-ec1a-cb84-d4da400b8f85@lab.ntt.co.jp
2017-11-02 22:22:08 +01:00
|
|
|
* Initialize a new BRIN index's metapage.
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
*/
|
|
|
|
void
|
|
|
|
brin_metapage_init(Page page, BlockNumber pagesPerRange, uint16 version)
|
|
|
|
{
|
|
|
|
BrinMetaPageData *metadata;
|
|
|
|
|
|
|
|
brin_page_init(page, BRIN_PAGETYPE_META);
|
|
|
|
|
|
|
|
metadata = (BrinMetaPageData *) PageGetContents(page);
|
|
|
|
|
|
|
|
metadata->brinMagic = BRIN_META_MAGIC;
|
|
|
|
metadata->brinVersion = version;
|
|
|
|
metadata->pagesPerRange = pagesPerRange;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Note we cheat here a little. 0 is not a valid revmap block number
|
|
|
|
* (because it's the metapage buffer), but doing this enables the first
|
|
|
|
* revmap page to be created when the index is.
|
|
|
|
*/
|
|
|
|
metadata->lastRevmapPage = 0;
|
Set the metapage's pd_lower correctly in brin, gin, and spgist indexes.
Previously, these index types left the pd_lower field set to the default
SizeOfPageHeaderData, which is really a lie because it ought to point past
whatever space is being used for metadata. The coding accidentally failed
to fail because we never told xlog.c that the metapage is of standard
format --- but that's not very good, because it impedes WAL consistency
checking, and in some cases prevents compression of full-page images.
To fix, ensure that we set pd_lower correctly, not only when creating a
metapage but whenever we write it out (these apparently redundant steps are
needed to cope with pg_upgrade'd indexes that don't yet contain the right
value). This allows telling xlog.c that the page is of standard format.
The WAL consistency check mask functions are made to mask only if pd_lower
appears valid, which I think is likely unnecessary complication, since
any metapage appearing in a v11 WAL stream should contain valid pd_lower.
But it doesn't cost much to be paranoid.
Amit Langote, reviewed by Michael Paquier and Amit Kapila
Discussion: https://postgr.es/m/0d273805-0e9e-ec1a-cb84-d4da400b8f85@lab.ntt.co.jp
2017-11-02 22:22:08 +01:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Set pd_lower just past the end of the metadata. This is essential,
|
|
|
|
* because without doing so, metadata will be lost if xlog.c compresses
|
|
|
|
* the page.
|
|
|
|
*/
|
|
|
|
((PageHeader) page)->pd_lower =
|
|
|
|
((char *) metadata + sizeof(BrinMetaPageData)) - (char *) page;
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Initiate page evacuation protocol.
|
|
|
|
*
|
|
|
|
* The page must be locked in exclusive mode by the caller.
|
|
|
|
*
|
|
|
|
* If the page is not yet initialized or empty, return false without doing
|
|
|
|
* anything; it can be used for revmap without any further changes. If it
|
|
|
|
* contains tuples, mark it for evacuation and return true.
|
|
|
|
*/
|
|
|
|
bool
|
|
|
|
brin_start_evacuating_page(Relation idxRel, Buffer buf)
|
|
|
|
{
|
|
|
|
OffsetNumber off;
|
|
|
|
OffsetNumber maxoff;
|
|
|
|
Page page;
|
|
|
|
|
2016-04-20 15:31:19 +02:00
|
|
|
page = BufferGetPage(buf);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
|
|
|
|
if (PageIsNew(page))
|
|
|
|
return false;
|
|
|
|
|
|
|
|
maxoff = PageGetMaxOffsetNumber(page);
|
|
|
|
for (off = FirstOffsetNumber; off <= maxoff; off++)
|
|
|
|
{
|
|
|
|
ItemId lp;
|
|
|
|
|
|
|
|
lp = PageGetItemId(page, off);
|
|
|
|
if (ItemIdIsUsed(lp))
|
|
|
|
{
|
|
|
|
/* prevent other backends from adding more stuff to this page */
|
2015-03-10 16:26:34 +01:00
|
|
|
BrinPageFlags(page) |= BRIN_EVACUATE_PAGE;
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
MarkBufferDirtyHint(buf, true);
|
|
|
|
|
|
|
|
return true;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Move all tuples out of a page.
|
|
|
|
*
|
|
|
|
* The caller must hold lock on the page. The lock and pin are released.
|
|
|
|
*/
|
|
|
|
void
|
|
|
|
brin_evacuate_page(Relation idxRel, BlockNumber pagesPerRange,
|
|
|
|
BrinRevmap *revmap, Buffer buf)
|
|
|
|
{
|
|
|
|
OffsetNumber off;
|
|
|
|
OffsetNumber maxoff;
|
|
|
|
Page page;
|
2017-04-07 23:54:26 +02:00
|
|
|
BrinTuple *btup = NULL;
|
|
|
|
Size btupsz = 0;
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
|
2016-04-20 15:31:19 +02:00
|
|
|
page = BufferGetPage(buf);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
|
2015-03-10 16:26:34 +01:00
|
|
|
Assert(BrinPageFlags(page) & BRIN_EVACUATE_PAGE);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
|
|
|
|
maxoff = PageGetMaxOffsetNumber(page);
|
|
|
|
for (off = FirstOffsetNumber; off <= maxoff; off++)
|
|
|
|
{
|
|
|
|
BrinTuple *tup;
|
|
|
|
Size sz;
|
|
|
|
ItemId lp;
|
|
|
|
|
|
|
|
CHECK_FOR_INTERRUPTS();
|
|
|
|
|
|
|
|
lp = PageGetItemId(page, off);
|
|
|
|
if (ItemIdIsUsed(lp))
|
|
|
|
{
|
|
|
|
sz = ItemIdGetLength(lp);
|
|
|
|
tup = (BrinTuple *) PageGetItem(page, lp);
|
2017-04-07 23:54:26 +02:00
|
|
|
tup = brin_copy_tuple(tup, sz, btup, &btupsz);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
|
|
|
|
LockBuffer(buf, BUFFER_LOCK_UNLOCK);
|
|
|
|
|
|
|
|
if (!brin_doupdate(idxRel, pagesPerRange, revmap, tup->bt_blkno,
|
|
|
|
buf, off, tup, sz, tup, sz, false))
|
|
|
|
off--; /* retry */
|
|
|
|
|
|
|
|
LockBuffer(buf, BUFFER_LOCK_SHARE);
|
|
|
|
|
|
|
|
/* It's possible that someone extended the revmap over this page */
|
|
|
|
if (!BRIN_IS_REGULAR_PAGE(page))
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
UnlockReleaseBuffer(buf);
|
|
|
|
}
|
|
|
|
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
/*
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
* Given a BRIN index page, initialize it if necessary, and record its
|
|
|
|
* current free space in the FSM.
|
|
|
|
*
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
* The main use for this is when, during vacuuming, an uninitialized page is
|
|
|
|
* found, which could be the result of relation extension followed by a crash
|
|
|
|
* before the page can be used.
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
*
|
|
|
|
* Here, we don't bother to update upper FSM pages, instead expecting that our
|
|
|
|
* caller (brin_vacuum_scan) will fix them at the end of the scan. Elsewhere
|
|
|
|
* in this file, it's generally a good idea to propagate additions of free
|
|
|
|
* space into the upper FSM pages immediately.
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
*/
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
void
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
brin_page_cleanup(Relation idxrel, Buffer buf)
|
|
|
|
{
|
2016-04-20 15:31:19 +02:00
|
|
|
Page page = BufferGetPage(buf);
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
|
|
|
|
/*
|
|
|
|
* If a page was left uninitialized, initialize it now; also record it in
|
|
|
|
* FSM.
|
|
|
|
*
|
|
|
|
* Somebody else might be extending the relation concurrently. To avoid
|
|
|
|
* re-initializing the page before they can grab the buffer lock, we
|
|
|
|
* acquire the extension lock momentarily. Since they hold the extension
|
|
|
|
* lock from before getting the page and after its been initialized, we're
|
|
|
|
* sure to see their initialization.
|
|
|
|
*/
|
|
|
|
if (PageIsNew(page))
|
|
|
|
{
|
|
|
|
LockRelationForExtension(idxrel, ShareLock);
|
|
|
|
UnlockRelationForExtension(idxrel, ShareLock);
|
|
|
|
|
|
|
|
LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
|
|
|
|
if (PageIsNew(page))
|
|
|
|
{
|
|
|
|
brin_initialize_empty_new_buffer(idxrel, buf);
|
|
|
|
LockBuffer(buf, BUFFER_LOCK_UNLOCK);
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
return;
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
}
|
|
|
|
LockBuffer(buf, BUFFER_LOCK_UNLOCK);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Nothing to be done for non-regular index pages */
|
2016-04-20 15:31:19 +02:00
|
|
|
if (BRIN_IS_META_PAGE(BufferGetPage(buf)) ||
|
|
|
|
BRIN_IS_REVMAP_PAGE(BufferGetPage(buf)))
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
return;
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
|
|
|
|
/* Measure free space and record it */
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
RecordPageWithFreeSpace(idxrel, BufferGetBlockNumber(buf),
|
|
|
|
br_page_get_freespace(page));
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
}
|
|
|
|
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
/*
|
|
|
|
* Return a pinned and exclusively locked buffer which can be used to insert an
|
2015-10-27 22:17:55 +01:00
|
|
|
* index item of size itemsz (caller must ensure not to request sizes
|
|
|
|
* impossible to fulfill). If oldbuf is a valid buffer, it is also locked (in
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
* an order determined to avoid deadlocks).
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
*
|
|
|
|
* If we find that the old page is no longer a regular index page (because
|
|
|
|
* of a revmap extension), the old buffer is unlocked and we return
|
|
|
|
* InvalidBuffer.
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
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|
*
|
|
|
|
* If there's no existing page with enough free space to accommodate the new
|
|
|
|
* item, the relation is extended. If this happens, *extended is set to true,
|
|
|
|
* and it is the caller's responsibility to initialize the page (and WAL-log
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
* that fact) prior to use. The caller should also update the FSM with the
|
|
|
|
* page's remaining free space after the insertion.
|
|
|
|
*
|
|
|
|
* Note that the caller is not expected to update FSM unless *extended is set
|
|
|
|
* true. This policy means that we'll update FSM when a page is created, and
|
|
|
|
* when it's found to have too little space for a desired tuple insertion,
|
|
|
|
* but not every single time we add a tuple to the page.
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
*
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
* Note that in some corner cases it is possible for this routine to extend
|
|
|
|
* the relation and then not return the new page. It is this routine's
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
* responsibility to WAL-log the page initialization and to record the page in
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
* FSM if that happens, since the caller certainly can't do it.
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
*/
|
|
|
|
static Buffer
|
|
|
|
brin_getinsertbuffer(Relation irel, Buffer oldbuf, Size itemsz,
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
bool *extended)
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
{
|
|
|
|
BlockNumber oldblk;
|
|
|
|
BlockNumber newblk;
|
|
|
|
Page page;
|
2017-06-04 17:41:16 +02:00
|
|
|
Size freespace;
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
|
2015-10-27 22:17:55 +01:00
|
|
|
/* callers must have checked */
|
|
|
|
Assert(itemsz <= BrinMaxItemSize);
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
if (BufferIsValid(oldbuf))
|
|
|
|
oldblk = BufferGetBlockNumber(oldbuf);
|
|
|
|
else
|
|
|
|
oldblk = InvalidBlockNumber;
|
|
|
|
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
/* Choose initial target page, re-using existing target if known */
|
|
|
|
newblk = RelationGetTargetBlock(irel);
|
|
|
|
if (newblk == InvalidBlockNumber)
|
|
|
|
newblk = GetPageWithFreeSpace(irel, itemsz);
|
|
|
|
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
/*
|
|
|
|
* Loop until we find a page with sufficient free space. By the time we
|
|
|
|
* return to caller out of this loop, both buffers are valid and locked;
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
* if we have to restart here, neither page is locked and newblk isn't
|
|
|
|
* pinned (if it's even valid).
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
*/
|
|
|
|
for (;;)
|
|
|
|
{
|
|
|
|
Buffer buf;
|
|
|
|
bool extensionLockHeld = false;
|
|
|
|
|
|
|
|
CHECK_FOR_INTERRUPTS();
|
|
|
|
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
*extended = false;
|
|
|
|
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
if (newblk == InvalidBlockNumber)
|
|
|
|
{
|
|
|
|
/*
|
|
|
|
* There's not enough free space in any existing index page,
|
|
|
|
* according to the FSM: extend the relation to obtain a shiny new
|
|
|
|
* page.
|
|
|
|
*/
|
|
|
|
if (!RELATION_IS_LOCAL(irel))
|
|
|
|
{
|
|
|
|
LockRelationForExtension(irel, ExclusiveLock);
|
|
|
|
extensionLockHeld = true;
|
|
|
|
}
|
|
|
|
buf = ReadBuffer(irel, P_NEW);
|
|
|
|
newblk = BufferGetBlockNumber(buf);
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
*extended = true;
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
|
2014-11-08 04:31:03 +01:00
|
|
|
BRIN_elog((DEBUG2, "brin_getinsertbuffer: extending to page %u",
|
|
|
|
BufferGetBlockNumber(buf)));
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
}
|
|
|
|
else if (newblk == oldblk)
|
|
|
|
{
|
|
|
|
/*
|
|
|
|
* There's an odd corner-case here where the FSM is out-of-date,
|
|
|
|
* and gave us the old page.
|
|
|
|
*/
|
|
|
|
buf = oldbuf;
|
|
|
|
}
|
|
|
|
else
|
|
|
|
{
|
|
|
|
buf = ReadBuffer(irel, newblk);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* We lock the old buffer first, if it's earlier than the new one; but
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
* then we need to check that it hasn't been turned into a revmap page
|
|
|
|
* concurrently. If we detect that that happened, give up and tell
|
|
|
|
* caller to start over.
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
*/
|
|
|
|
if (BufferIsValid(oldbuf) && oldblk < newblk)
|
|
|
|
{
|
|
|
|
LockBuffer(oldbuf, BUFFER_LOCK_EXCLUSIVE);
|
2016-04-20 15:31:19 +02:00
|
|
|
if (!BRIN_IS_REGULAR_PAGE(BufferGetPage(oldbuf)))
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
{
|
|
|
|
LockBuffer(oldbuf, BUFFER_LOCK_UNLOCK);
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
|
|
|
|
/*
|
|
|
|
* It is possible that the new page was obtained from
|
|
|
|
* extending the relation. In that case, we must be sure to
|
|
|
|
* record it in the FSM before leaving, because otherwise the
|
|
|
|
* space would be lost forever. However, we cannot let an
|
|
|
|
* uninitialized page get in the FSM, so we need to initialize
|
|
|
|
* it first.
|
|
|
|
*/
|
|
|
|
if (*extended)
|
|
|
|
brin_initialize_empty_new_buffer(irel, buf);
|
|
|
|
|
|
|
|
if (extensionLockHeld)
|
|
|
|
UnlockRelationForExtension(irel, ExclusiveLock);
|
|
|
|
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
ReleaseBuffer(buf);
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
|
|
|
|
if (*extended)
|
|
|
|
{
|
|
|
|
FreeSpaceMapVacuumRange(irel, newblk, newblk + 1);
|
|
|
|
/* shouldn't matter, but don't confuse caller */
|
|
|
|
*extended = false;
|
|
|
|
}
|
|
|
|
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
return InvalidBuffer;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
|
|
|
|
|
|
|
|
if (extensionLockHeld)
|
|
|
|
UnlockRelationForExtension(irel, ExclusiveLock);
|
|
|
|
|
2016-04-20 15:31:19 +02:00
|
|
|
page = BufferGetPage(buf);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
|
|
|
|
/*
|
|
|
|
* We have a new buffer to insert into. Check that the new page has
|
|
|
|
* enough free space, and return it if it does; otherwise start over.
|
|
|
|
* (br_page_get_freespace also checks that the FSM didn't hand us a
|
|
|
|
* page that has since been repurposed for the revmap.)
|
|
|
|
*/
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
freespace = *extended ?
|
2015-10-27 22:17:55 +01:00
|
|
|
BrinMaxItemSize : br_page_get_freespace(page);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
if (freespace >= itemsz)
|
|
|
|
{
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
RelationSetTargetBlock(irel, newblk);
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Lock the old buffer if not locked already. Note that in this
|
|
|
|
* case we know for sure it's a regular page: it's later than the
|
|
|
|
* new page we just got, which is not a revmap page, and revmap
|
|
|
|
* pages are always consecutive.
|
|
|
|
*/
|
|
|
|
if (BufferIsValid(oldbuf) && oldblk > newblk)
|
|
|
|
{
|
|
|
|
LockBuffer(oldbuf, BUFFER_LOCK_EXCLUSIVE);
|
2016-04-20 15:31:19 +02:00
|
|
|
Assert(BRIN_IS_REGULAR_PAGE(BufferGetPage(oldbuf)));
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
}
|
|
|
|
|
|
|
|
return buf;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* This page is no good. */
|
|
|
|
|
|
|
|
/*
|
|
|
|
* If an entirely new page does not contain enough free space for the
|
|
|
|
* new item, then surely that item is oversized. Complain loudly; but
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
* first make sure we initialize the page and record it as free, for
|
|
|
|
* next time.
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
*/
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
if (*extended)
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
{
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
brin_initialize_empty_new_buffer(irel, buf);
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
/* since this should not happen, skip FreeSpaceMapVacuum */
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
ereport(ERROR,
|
|
|
|
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
|
Phase 3 of pgindent updates.
Don't move parenthesized lines to the left, even if that means they
flow past the right margin.
By default, BSD indent lines up statement continuation lines that are
within parentheses so that they start just to the right of the preceding
left parenthesis. However, traditionally, if that resulted in the
continuation line extending to the right of the desired right margin,
then indent would push it left just far enough to not overrun the margin,
if it could do so without making the continuation line start to the left of
the current statement indent. That makes for a weird mix of indentations
unless one has been completely rigid about never violating the 80-column
limit.
This behavior has been pretty universally panned by Postgres developers.
Hence, disable it with indent's new -lpl switch, so that parenthesized
lines are always lined up with the preceding left paren.
This patch is much less interesting than the first round of indent
changes, but also bulkier, so I thought it best to separate the effects.
Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org
Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 21:35:54 +02:00
|
|
|
errmsg("index row size %zu exceeds maximum %zu for index \"%s\"",
|
|
|
|
itemsz, freespace, RelationGetRelationName(irel))));
|
Phase 2 of pgindent updates.
Change pg_bsd_indent to follow upstream rules for placement of comments
to the right of code, and remove pgindent hack that caused comments
following #endif to not obey the general rule.
Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using
the published version of pg_bsd_indent, but a hacked-up version that
tried to minimize the amount of movement of comments to the right of
code. The situation of interest is where such a comment has to be
moved to the right of its default placement at column 33 because there's
code there. BSD indent has always moved right in units of tab stops
in such cases --- but in the previous incarnation, indent was working
in 8-space tab stops, while now it knows we use 4-space tabs. So the
net result is that in about half the cases, such comments are placed
one tab stop left of before. This is better all around: it leaves
more room on the line for comment text, and it means that in such
cases the comment uniformly starts at the next 4-space tab stop after
the code, rather than sometimes one and sometimes two tabs after.
Also, ensure that comments following #endif are indented the same
as comments following other preprocessor commands such as #else.
That inconsistency turns out to have been self-inflicted damage
from a poorly-thought-through post-indent "fixup" in pgindent.
This patch is much less interesting than the first round of indent
changes, but also bulkier, so I thought it best to separate the effects.
Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org
Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 21:18:54 +02:00
|
|
|
return InvalidBuffer; /* keep compiler quiet */
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
}
|
|
|
|
|
|
|
|
if (newblk != oldblk)
|
|
|
|
UnlockReleaseBuffer(buf);
|
|
|
|
if (BufferIsValid(oldbuf) && oldblk <= newblk)
|
|
|
|
LockBuffer(oldbuf, BUFFER_LOCK_UNLOCK);
|
|
|
|
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
|
|
|
/*
|
|
|
|
* Update the FSM with the new, presumably smaller, freespace value
|
|
|
|
* for this page, then search for a new target page.
|
|
|
|
*/
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
newblk = RecordAndGetPageWithFreeSpace(irel, newblk, freespace, itemsz);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
|
|
/*
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* Initialize a page as an empty regular BRIN page, WAL-log this, and record
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* the page in FSM.
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*
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* There are several corner situations in which we extend the relation to
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* obtain a new page and later find that we cannot use it immediately. When
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* that happens, we don't want to leave the page go unrecorded in FSM, because
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* there is no mechanism to get the space back and the index would bloat.
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* Also, because we would not WAL-log the action that would initialize the
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* page, the page would go uninitialized in a standby (or after recovery).
|
Improve FSM management for BRIN indexes.
BRIN indexes like to propagate additions of free space into the upper pages
of their free space maps as soon as the new space is known, even when it's
just on one individual index page. Previously this required calling
FreeSpaceMapVacuum, which is quite an expensive thing if the map is large.
Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75
to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all
after recording new free space. If the policy is to be that BRIN should do
that, it should do it everywhere.
Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do
FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the
FSM's imprecise storage of free space, the old complications here seldom
bought anything, they just slowed things down. This approach also
provides a predictable path for FSM corruption to be repaired.
Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer
where it's about to return an extended page to the caller. The caller
should do that, instead, after it's inserted its new tuple. Fix the
one caller that forgot to do so.
Simplify logic in brin_doupdate's same-page-update case by postponing
brin_initialize_empty_new_buffer to after the critical section; I see
little point in doing it before.
Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan.
Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in
a couple of places where we already had the right values.
Move a BRIN_elog debug logging call out of a critical section; that's
pretty unsafe and I don't think it buys us anything to not wait till
after the critical section.
Move the "*extended = false" step in brin_getinsertbuffer into the
routine's main loop. There's no actual bug there, since the loop can't
iterate with *extended still true, but it doesn't seem very future-proof
as coded; and it's certainly not documented as a loop invariant.
This is all from follow-on investigation inspired by commit c79f6df75.
Discussion: https://postgr.es/m/5801.1522429460@sss.pgh.pa.us
2018-04-04 20:26:04 +02:00
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*
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* While we record the page in FSM here, caller is responsible for doing FSM
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* upper-page update if that seems appropriate.
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
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*/
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static void
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brin_initialize_empty_new_buffer(Relation idxrel, Buffer buffer)
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{
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Page page;
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BRIN_elog((DEBUG2,
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"brin_initialize_empty_new_buffer: initializing blank page %u",
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BufferGetBlockNumber(buffer)));
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START_CRIT_SECTION();
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2016-04-20 15:31:19 +02:00
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page = BufferGetPage(buffer);
|
Close some holes in BRIN page assignment
In some corner cases, it is possible for the BRIN index relation to be
extended by brin_getinsertbuffer but the new page not be used
immediately for anything by its callers; when this happens, the page is
initialized and the FSM is updated (by brin_getinsertbuffer) with the
info about that page, but these actions are not WAL-logged. A later
index insert/update can use the page, but since the page is already
initialized, the initialization itself is not WAL-logged then either.
Replay of this sequence of events causes recovery to fail altogether.
There is a related corner case within brin_getinsertbuffer itself, in
which we extend the relation to put a new index tuple there, but later
find out that we cannot do so, and do not return the buffer; the page
obtained from extension is not even initialized. The resulting page is
lost forever.
To fix, shuffle the code so that initialization is not the
responsibility of brin_getinsertbuffer anymore, in normal cases;
instead, the initialization is done by its callers (brin_doinsert and
brin_doupdate) once they're certain that the page is going to be used.
When either those functions determine that the new page cannot be used,
before bailing out they initialize the page as an empty regular page,
enter it in FSM and WAL-log all this. This way, the page is usable for
future index insertions, and WAL replay doesn't find trying to insert
tuples in pages whose initialization didn't make it to the WAL. The
same strategy is used in brin_getinsertbuffer when it cannot return the
new page.
Additionally, add a new step to vacuuming so that all pages of the index
are scanned; whenever an uninitialized page is found, it is initialized
as empty and WAL-logged. This closes the hole that the relation is
extended but the system crashes before anything is WAL-logged about it.
We also take this opportunity to update the FSM, in case it has gotten
out of date.
Thanks to Heikki Linnakangas for finding the problem that kicked some
additional analysis of BRIN page assignment code.
Backpatch to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
2015-08-12 19:20:38 +02:00
|
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brin_page_init(page, BRIN_PAGETYPE_REGULAR);
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|
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|
MarkBufferDirty(buffer);
|
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|
|
log_newpage_buffer(buffer, true);
|
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|
END_CRIT_SECTION();
|
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/*
|
|
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|
* We update the FSM for this page, but this is not WAL-logged. This is
|
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|
* acceptable because VACUUM will scan the index and update the FSM with
|
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|
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* pages whose FSM records were forgotten in a crash.
|
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|
*/
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RecordPageWithFreeSpace(idxrel, BufferGetBlockNumber(buffer),
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|
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|
br_page_get_freespace(page));
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|
}
|
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|
|
|
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|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
/*
|
|
|
|
* Return the amount of free space on a regular BRIN index page.
|
|
|
|
*
|
|
|
|
* If the page is not a regular page, or has been marked with the
|
|
|
|
* BRIN_EVACUATE_PAGE flag, returns 0.
|
|
|
|
*/
|
|
|
|
static Size
|
|
|
|
br_page_get_freespace(Page page)
|
|
|
|
{
|
|
|
|
if (!BRIN_IS_REGULAR_PAGE(page) ||
|
2015-03-10 16:26:34 +01:00
|
|
|
(BrinPageFlags(page) & BRIN_EVACUATE_PAGE) != 0)
|
BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes. They work by maintaining "summary" data about
block ranges. Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not. Normal index scans are not supported
because these indexes do not store TIDs.
As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.
For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range. This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results. In this commit I only include minmax.
Catalog version bumped due to new builtin catalog entries.
There's more that could be done here, but this is a good step forwards.
Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.
Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.
PS:
The research leading to these results has received funding from the
European Union's Seventh Framework Programme (FP7/2007-2013) under
grant agreement n° 318633.
2014-11-07 20:38:14 +01:00
|
|
|
return 0;
|
|
|
|
else
|
|
|
|
return PageGetFreeSpace(page);
|
|
|
|
}
|