2001-07-14 00:55:59 +02:00
|
|
|
/*-------------------------------------------------------------------------
|
|
|
|
*
|
|
|
|
* vacuumlazy.c
|
|
|
|
* Concurrent ("lazy") vacuuming.
|
|
|
|
*
|
|
|
|
*
|
|
|
|
* The major space usage for LAZY VACUUM is storage for the array of dead
|
|
|
|
* tuple TIDs, with the next biggest need being storage for per-disk-page
|
|
|
|
* free space info. We want to ensure we can vacuum even the very largest
|
|
|
|
* relations with finite memory space usage. To do that, we set upper bounds
|
|
|
|
* on the number of tuples and pages we will keep track of at once.
|
|
|
|
*
|
2004-02-03 18:34:04 +01:00
|
|
|
* We are willing to use at most maintenance_work_mem memory space to keep
|
2007-09-24 05:52:55 +02:00
|
|
|
* track of dead tuples. We initially allocate an array of TIDs of that size,
|
|
|
|
* with an upper limit that depends on table size (this limit ensures we don't
|
2007-11-15 22:14:46 +01:00
|
|
|
* allocate a huge area uselessly for vacuuming small tables). If the array
|
2007-09-24 05:52:55 +02:00
|
|
|
* threatens to overflow, we suspend the heap scan phase and perform a pass of
|
|
|
|
* index cleanup and page compaction, then resume the heap scan with an empty
|
|
|
|
* TID array.
|
2001-07-14 00:55:59 +02:00
|
|
|
*
|
2006-09-13 19:47:08 +02:00
|
|
|
* If we're processing a table with no indexes, we can just vacuum each page
|
|
|
|
* as we go; there's no need to save up multiple tuples to minimize the number
|
|
|
|
* of index scans performed. So we don't use maintenance_work_mem memory for
|
|
|
|
* the TID array, just enough to hold as many heap tuples as fit on one page.
|
|
|
|
*
|
2001-07-14 00:55:59 +02:00
|
|
|
*
|
2011-01-01 19:18:15 +01:00
|
|
|
* Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group
|
2001-07-14 00:55:59 +02:00
|
|
|
* Portions Copyright (c) 1994, Regents of the University of California
|
|
|
|
*
|
|
|
|
*
|
|
|
|
* IDENTIFICATION
|
2010-09-20 22:08:53 +02:00
|
|
|
* src/backend/commands/vacuumlazy.c
|
2001-07-14 00:55:59 +02:00
|
|
|
*
|
|
|
|
*-------------------------------------------------------------------------
|
|
|
|
*/
|
|
|
|
#include "postgres.h"
|
|
|
|
|
2004-12-01 20:00:56 +01:00
|
|
|
#include <math.h>
|
|
|
|
|
2001-07-14 00:55:59 +02:00
|
|
|
#include "access/genam.h"
|
|
|
|
#include "access/heapam.h"
|
2006-07-13 18:49:20 +02:00
|
|
|
#include "access/transam.h"
|
2008-12-03 14:05:22 +01:00
|
|
|
#include "access/visibilitymap.h"
|
2008-11-19 11:34:52 +01:00
|
|
|
#include "catalog/storage.h"
|
2007-04-18 18:44:18 +02:00
|
|
|
#include "commands/dbcommands.h"
|
2001-07-14 00:55:59 +02:00
|
|
|
#include "commands/vacuum.h"
|
|
|
|
#include "miscadmin.h"
|
2005-07-14 07:13:45 +02:00
|
|
|
#include "pgstat.h"
|
2007-04-18 18:44:18 +02:00
|
|
|
#include "postmaster/autovacuum.h"
|
2008-05-12 02:00:54 +02:00
|
|
|
#include "storage/bufmgr.h"
|
2001-07-14 00:55:59 +02:00
|
|
|
#include "storage/freespace.h"
|
2008-05-12 02:00:54 +02:00
|
|
|
#include "storage/lmgr.h"
|
2002-04-02 03:03:07 +02:00
|
|
|
#include "utils/lsyscache.h"
|
2006-03-04 20:09:09 +01:00
|
|
|
#include "utils/memutils.h"
|
2005-10-04 00:52:26 +02:00
|
|
|
#include "utils/pg_rusage.h"
|
2011-09-09 19:23:41 +02:00
|
|
|
#include "utils/timestamp.h"
|
2008-03-26 22:10:39 +01:00
|
|
|
#include "utils/tqual.h"
|
2001-07-14 00:55:59 +02:00
|
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Space/time tradeoff parameters: do these need to be user-tunable?
|
|
|
|
*
|
|
|
|
* To consider truncating the relation, we want there to be at least
|
2003-03-04 22:51:22 +01:00
|
|
|
* REL_TRUNCATE_MINIMUM or (relsize / REL_TRUNCATE_FRACTION) (whichever
|
|
|
|
* is less) potentially-freeable pages.
|
2001-07-14 00:55:59 +02:00
|
|
|
*/
|
2003-03-04 22:51:22 +01:00
|
|
|
#define REL_TRUNCATE_MINIMUM 1000
|
2001-07-14 00:55:59 +02:00
|
|
|
#define REL_TRUNCATE_FRACTION 16
|
|
|
|
|
2007-09-24 05:52:55 +02:00
|
|
|
/*
|
|
|
|
* Guesstimation of number of dead tuples per page. This is used to
|
|
|
|
* provide an upper limit to memory allocated when vacuuming small
|
|
|
|
* tables.
|
|
|
|
*/
|
2007-09-26 22:16:28 +02:00
|
|
|
#define LAZY_ALLOC_TUPLES MaxHeapTuplesPerPage
|
2001-07-14 00:55:59 +02:00
|
|
|
|
2009-01-22 20:25:00 +01:00
|
|
|
/*
|
|
|
|
* Before we consider skipping a page that's marked as clean in
|
|
|
|
* visibility map, we must've seen at least this many clean pages.
|
|
|
|
*/
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
#define SKIP_PAGES_THRESHOLD ((BlockNumber) 32)
|
2009-01-22 20:25:00 +01:00
|
|
|
|
2001-07-14 00:55:59 +02:00
|
|
|
typedef struct LVRelStats
|
|
|
|
{
|
2006-09-13 19:47:08 +02:00
|
|
|
/* hasindex = true means two-pass strategy; false means one-pass */
|
|
|
|
bool hasindex;
|
2001-07-14 00:55:59 +02:00
|
|
|
/* Overall statistics about rel */
|
Fix a missed case in code for "moving average" estimate of reltuples.
It is possible for VACUUM to scan no pages at all, if the visibility map
shows that all pages are all-visible. In this situation VACUUM has no new
information to report about the relation's tuple density, so it wasn't
changing pg_class.reltuples ... but it updated pg_class.relpages anyway.
That's wrong in general, since there is no evidence to justify changing the
density ratio reltuples/relpages, but it's particularly bad if the previous
state was relpages=reltuples=0, which means "unknown tuple density".
We just replaced "unknown" with "zero". ANALYZE would eventually recover
from this, but it could take a lot of repetitions of ANALYZE to do so if
the relation size is much larger than the maximum number of pages ANALYZE
will scan, because of the moving-average behavior introduced by commit
b4b6923e03f4d29636a94f6f4cc2f5cf6298b8c8.
The only known situation where we could have relpages=reltuples=0 and yet
the visibility map asserts everything's visible is immediately following
a pg_upgrade. It might be advisable for pg_upgrade to try to preserve the
relpages/reltuples statistics; but in any case this code is wrong on its
own terms, so fix it. Per report from Sergey Koposov.
Back-patch to 8.4, where the visibility map was introduced, same as the
previous change.
2011-08-30 20:49:45 +02:00
|
|
|
BlockNumber old_rel_pages; /* previous value of pg_class.relpages */
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
BlockNumber rel_pages; /* total number of pages */
|
|
|
|
BlockNumber scanned_pages; /* number of pages we examined */
|
2011-06-09 20:32:50 +02:00
|
|
|
double scanned_tuples; /* counts only tuples on scanned pages */
|
2009-06-11 16:49:15 +02:00
|
|
|
double old_rel_tuples; /* previous value of pg_class.reltuples */
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
double new_rel_tuples; /* new estimated total # of tuples */
|
2005-10-15 04:49:52 +02:00
|
|
|
BlockNumber pages_removed;
|
2004-12-01 20:00:56 +01:00
|
|
|
double tuples_deleted;
|
2001-10-25 07:50:21 +02:00
|
|
|
BlockNumber nonempty_pages; /* actually, last nonempty page + 1 */
|
2001-07-14 00:55:59 +02:00
|
|
|
/* List of TIDs of tuples we intend to delete */
|
|
|
|
/* NB: this list is ordered by TID address */
|
2001-10-28 07:26:15 +01:00
|
|
|
int num_dead_tuples; /* current # of entries */
|
|
|
|
int max_dead_tuples; /* # slots allocated in array */
|
2001-10-25 07:50:21 +02:00
|
|
|
ItemPointer dead_tuples; /* array of ItemPointerData */
|
2007-04-18 18:44:18 +02:00
|
|
|
int num_index_scans;
|
Allow read only connections during recovery, known as Hot Standby.
Enabled by recovery_connections = on (default) and forcing archive recovery using a recovery.conf. Recovery processing now emulates the original transactions as they are replayed, providing full locking and MVCC behaviour for read only queries. Recovery must enter consistent state before connections are allowed, so there is a delay, typically short, before connections succeed. Replay of recovering transactions can conflict and in some cases deadlock with queries during recovery; these result in query cancellation after max_standby_delay seconds have expired. Infrastructure changes have minor effects on normal running, though introduce four new types of WAL record.
New test mode "make standbycheck" allows regression tests of static command behaviour on a standby server while in recovery. Typical and extreme dynamic behaviours have been checked via code inspection and manual testing. Few port specific behaviours have been utilised, though primary testing has been on Linux only so far.
This commit is the basic patch. Additional changes will follow in this release to enhance some aspects of behaviour, notably improved handling of conflicts, deadlock detection and query cancellation. Changes to VACUUM FULL are also required.
Simon Riggs, with significant and lengthy review by Heikki Linnakangas, including streamlined redesign of snapshot creation and two-phase commit.
Important contributions from Florian Pflug, Mark Kirkwood, Merlin Moncure, Greg Stark, Gianni Ciolli, Gabriele Bartolini, Hannu Krosing, Robert Haas, Tatsuo Ishii, Hiroyuki Yamada plus support and feedback from many other community members.
2009-12-19 02:32:45 +01:00
|
|
|
TransactionId latestRemovedXid;
|
2001-07-14 00:55:59 +02:00
|
|
|
} LVRelStats;
|
|
|
|
|
|
|
|
|
2007-05-30 22:12:03 +02:00
|
|
|
/* A few variables that don't seem worth passing around as parameters */
|
2002-09-04 22:31:48 +02:00
|
|
|
static int elevel = -1;
|
2001-07-14 00:55:59 +02:00
|
|
|
|
Fix recently-understood problems with handling of XID freezing, particularly
in PITR scenarios. We now WAL-log the replacement of old XIDs with
FrozenTransactionId, so that such replacement is guaranteed to propagate to
PITR slave databases. Also, rather than relying on hint-bit updates to be
preserved, pg_clog is not truncated until all instances of an XID are known to
have been replaced by FrozenTransactionId. Add new GUC variables and
pg_autovacuum columns to allow management of the freezing policy, so that
users can trade off the size of pg_clog against the amount of freezing work
done. Revise the already-existing code that forces autovacuum of tables
approaching the wraparound point to make it more bulletproof; also, revise the
autovacuum logic so that anti-wraparound vacuuming is done per-table rather
than per-database. initdb forced because of changes in pg_class, pg_database,
and pg_autovacuum catalogs. Heikki Linnakangas, Simon Riggs, and Tom Lane.
2006-11-05 23:42:10 +01:00
|
|
|
static TransactionId OldestXmin;
|
|
|
|
static TransactionId FreezeLimit;
|
|
|
|
|
2007-05-30 22:12:03 +02:00
|
|
|
static BufferAccessStrategy vac_strategy;
|
|
|
|
|
2001-07-14 00:55:59 +02:00
|
|
|
|
|
|
|
/* non-export function prototypes */
|
|
|
|
static void lazy_scan_heap(Relation onerel, LVRelStats *vacrelstats,
|
2008-12-03 14:05:22 +01:00
|
|
|
Relation *Irel, int nindexes, bool scan_all);
|
2001-07-14 00:55:59 +02:00
|
|
|
static void lazy_vacuum_heap(Relation onerel, LVRelStats *vacrelstats);
|
2004-12-01 20:00:56 +01:00
|
|
|
static void lazy_vacuum_index(Relation indrel,
|
2006-10-04 02:30:14 +02:00
|
|
|
IndexBulkDeleteResult **stats,
|
|
|
|
LVRelStats *vacrelstats);
|
2006-05-03 00:25:10 +02:00
|
|
|
static void lazy_cleanup_index(Relation indrel,
|
2006-10-04 02:30:14 +02:00
|
|
|
IndexBulkDeleteResult *stats,
|
|
|
|
LVRelStats *vacrelstats);
|
2001-10-25 07:50:21 +02:00
|
|
|
static int lazy_vacuum_page(Relation onerel, BlockNumber blkno, Buffer buffer,
|
|
|
|
int tupindex, LVRelStats *vacrelstats);
|
2010-02-09 22:43:30 +01:00
|
|
|
static void lazy_truncate_heap(Relation onerel, LVRelStats *vacrelstats);
|
2001-07-14 00:55:59 +02:00
|
|
|
static BlockNumber count_nondeletable_pages(Relation onerel,
|
Fix recently-understood problems with handling of XID freezing, particularly
in PITR scenarios. We now WAL-log the replacement of old XIDs with
FrozenTransactionId, so that such replacement is guaranteed to propagate to
PITR slave databases. Also, rather than relying on hint-bit updates to be
preserved, pg_clog is not truncated until all instances of an XID are known to
have been replaced by FrozenTransactionId. Add new GUC variables and
pg_autovacuum columns to allow management of the freezing policy, so that
users can trade off the size of pg_clog against the amount of freezing work
done. Revise the already-existing code that forces autovacuum of tables
approaching the wraparound point to make it more bulletproof; also, revise the
autovacuum logic so that anti-wraparound vacuuming is done per-table rather
than per-database. initdb forced because of changes in pg_class, pg_database,
and pg_autovacuum catalogs. Heikki Linnakangas, Simon Riggs, and Tom Lane.
2006-11-05 23:42:10 +01:00
|
|
|
LVRelStats *vacrelstats);
|
2006-09-13 19:47:08 +02:00
|
|
|
static void lazy_space_alloc(LVRelStats *vacrelstats, BlockNumber relblocks);
|
2001-07-14 00:55:59 +02:00
|
|
|
static void lazy_record_dead_tuple(LVRelStats *vacrelstats,
|
2001-10-25 07:50:21 +02:00
|
|
|
ItemPointer itemptr);
|
Restructure index AM interface for index building and index tuple deletion,
per previous discussion on pghackers. Most of the duplicate code in
different AMs' ambuild routines has been moved out to a common routine
in index.c; this means that all index types now do the right things about
inserting recently-dead tuples, etc. (I also removed support for EXTEND
INDEX in the ambuild routines, since that's about to go away anyway, and
it cluttered the code a lot.) The retail indextuple deletion routines have
been replaced by a "bulk delete" routine in which the indexscan is inside
the access method. I haven't pushed this change as far as it should go yet,
but it should allow considerable simplification of the internal bookkeeping
for deletions. Also, add flag columns to pg_am to eliminate various
hardcoded tests on AM OIDs, and remove unused pg_am columns.
Fix rtree and gist index types to not attempt to store NULLs; before this,
gist usually crashed, while rtree managed not to crash but computed wacko
bounding boxes for NULL entries (which might have had something to do with
the performance problems we've heard about occasionally).
Add AtEOXact routines to hash, rtree, and gist, all of which have static
state that needs to be reset after an error. We discovered this need long
ago for btree, but missed the other guys.
Oh, one more thing: concurrent VACUUM is now the default.
2001-07-16 00:48:19 +02:00
|
|
|
static bool lazy_tid_reaped(ItemPointer itemptr, void *state);
|
2001-07-14 00:55:59 +02:00
|
|
|
static int vac_cmp_itemptr(const void *left, const void *right);
|
|
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
* lazy_vacuum_rel() -- perform LAZY VACUUM for one heap relation
|
|
|
|
*
|
|
|
|
* This routine vacuums a single heap, cleans out its indexes, and
|
Fix recently-understood problems with handling of XID freezing, particularly
in PITR scenarios. We now WAL-log the replacement of old XIDs with
FrozenTransactionId, so that such replacement is guaranteed to propagate to
PITR slave databases. Also, rather than relying on hint-bit updates to be
preserved, pg_clog is not truncated until all instances of an XID are known to
have been replaced by FrozenTransactionId. Add new GUC variables and
pg_autovacuum columns to allow management of the freezing policy, so that
users can trade off the size of pg_clog against the amount of freezing work
done. Revise the already-existing code that forces autovacuum of tables
approaching the wraparound point to make it more bulletproof; also, revise the
autovacuum logic so that anti-wraparound vacuuming is done per-table rather
than per-database. initdb forced because of changes in pg_class, pg_database,
and pg_autovacuum catalogs. Heikki Linnakangas, Simon Riggs, and Tom Lane.
2006-11-05 23:42:10 +01:00
|
|
|
* updates its relpages and reltuples statistics.
|
2001-07-14 00:55:59 +02:00
|
|
|
*
|
|
|
|
* At entry, we have already established a transaction and opened
|
|
|
|
* and locked the relation.
|
|
|
|
*/
|
2010-02-09 22:43:30 +01:00
|
|
|
void
|
2007-05-30 22:12:03 +02:00
|
|
|
lazy_vacuum_rel(Relation onerel, VacuumStmt *vacstmt,
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
BufferAccessStrategy bstrategy)
|
2001-07-14 00:55:59 +02:00
|
|
|
{
|
|
|
|
LVRelStats *vacrelstats;
|
|
|
|
Relation *Irel;
|
|
|
|
int nindexes;
|
2001-10-25 07:50:21 +02:00
|
|
|
BlockNumber possibly_freeable;
|
2007-04-18 18:44:18 +02:00
|
|
|
PGRUsage ru0;
|
2007-11-15 22:14:46 +01:00
|
|
|
TimestampTz starttime = 0;
|
2009-01-16 14:27:24 +01:00
|
|
|
bool scan_all;
|
|
|
|
TransactionId freezeTableLimit;
|
Fix a missed case in code for "moving average" estimate of reltuples.
It is possible for VACUUM to scan no pages at all, if the visibility map
shows that all pages are all-visible. In this situation VACUUM has no new
information to report about the relation's tuple density, so it wasn't
changing pg_class.reltuples ... but it updated pg_class.relpages anyway.
That's wrong in general, since there is no evidence to justify changing the
density ratio reltuples/relpages, but it's particularly bad if the previous
state was relpages=reltuples=0, which means "unknown tuple density".
We just replaced "unknown" with "zero". ANALYZE would eventually recover
from this, but it could take a lot of repetitions of ANALYZE to do so if
the relation size is much larger than the maximum number of pages ANALYZE
will scan, because of the moving-average behavior introduced by commit
b4b6923e03f4d29636a94f6f4cc2f5cf6298b8c8.
The only known situation where we could have relpages=reltuples=0 and yet
the visibility map asserts everything's visible is immediately following
a pg_upgrade. It might be advisable for pg_upgrade to try to preserve the
relpages/reltuples statistics; but in any case this code is wrong on its
own terms, so fix it. Per report from Sergey Koposov.
Back-patch to 8.4, where the visibility map was introduced, same as the
previous change.
2011-08-30 20:49:45 +02:00
|
|
|
BlockNumber new_rel_pages;
|
|
|
|
double new_rel_tuples;
|
|
|
|
TransactionId new_frozen_xid;
|
2007-04-18 18:44:18 +02:00
|
|
|
|
|
|
|
/* measure elapsed time iff autovacuum logging requires it */
|
2011-08-18 15:55:04 +02:00
|
|
|
if (IsAutoVacuumWorkerProcess() && Log_autovacuum_min_duration >= 0)
|
|
|
|
{
|
|
|
|
pg_rusage_init(&ru0);
|
|
|
|
if (Log_autovacuum_min_duration > 0)
|
|
|
|
starttime = GetCurrentTimestamp();
|
|
|
|
}
|
2001-07-14 00:55:59 +02:00
|
|
|
|
2009-11-16 22:32:07 +01:00
|
|
|
if (vacstmt->options & VACOPT_VERBOSE)
|
Commit to match discussed elog() changes. Only update is that LOG is
now just below FATAL in server_min_messages. Added more text to
highlight ordering difference between it and client_min_messages.
---------------------------------------------------------------------------
REALLYFATAL => PANIC
STOP => PANIC
New INFO level the prints to client by default
New LOG level the prints to server log by default
Cause VACUUM information to print only to the client
NOTICE => INFO where purely information messages are sent
DEBUG => LOG for purely server status messages
DEBUG removed, kept as backward compatible
DEBUG5, DEBUG4, DEBUG3, DEBUG2, DEBUG1 added
DebugLvl removed in favor of new DEBUG[1-5] symbols
New server_min_messages GUC parameter with values:
DEBUG[5-1], INFO, NOTICE, ERROR, LOG, FATAL, PANIC
New client_min_messages GUC parameter with values:
DEBUG[5-1], LOG, INFO, NOTICE, ERROR, FATAL, PANIC
Server startup now logged with LOG instead of DEBUG
Remove debug_level GUC parameter
elog() numbers now start at 10
Add test to print error message if older elog() values are passed to elog()
Bootstrap mode now has a -d that requires an argument, like postmaster
2002-03-02 22:39:36 +01:00
|
|
|
elevel = INFO;
|
2001-07-14 00:55:59 +02:00
|
|
|
else
|
2003-05-27 19:49:47 +02:00
|
|
|
elevel = DEBUG2;
|
2002-03-06 07:10:59 +01:00
|
|
|
|
2007-05-30 22:12:03 +02:00
|
|
|
vac_strategy = bstrategy;
|
|
|
|
|
2009-01-16 14:27:24 +01:00
|
|
|
vacuum_set_xid_limits(vacstmt->freeze_min_age, vacstmt->freeze_table_age,
|
|
|
|
onerel->rd_rel->relisshared,
|
|
|
|
&OldestXmin, &FreezeLimit, &freezeTableLimit);
|
|
|
|
scan_all = TransactionIdPrecedesOrEquals(onerel->rd_rel->relfrozenxid,
|
|
|
|
freezeTableLimit);
|
2001-07-14 00:55:59 +02:00
|
|
|
|
2002-11-13 01:39:48 +01:00
|
|
|
vacrelstats = (LVRelStats *) palloc0(sizeof(LVRelStats));
|
2001-07-14 00:55:59 +02:00
|
|
|
|
Fix a missed case in code for "moving average" estimate of reltuples.
It is possible for VACUUM to scan no pages at all, if the visibility map
shows that all pages are all-visible. In this situation VACUUM has no new
information to report about the relation's tuple density, so it wasn't
changing pg_class.reltuples ... but it updated pg_class.relpages anyway.
That's wrong in general, since there is no evidence to justify changing the
density ratio reltuples/relpages, but it's particularly bad if the previous
state was relpages=reltuples=0, which means "unknown tuple density".
We just replaced "unknown" with "zero". ANALYZE would eventually recover
from this, but it could take a lot of repetitions of ANALYZE to do so if
the relation size is much larger than the maximum number of pages ANALYZE
will scan, because of the moving-average behavior introduced by commit
b4b6923e03f4d29636a94f6f4cc2f5cf6298b8c8.
The only known situation where we could have relpages=reltuples=0 and yet
the visibility map asserts everything's visible is immediately following
a pg_upgrade. It might be advisable for pg_upgrade to try to preserve the
relpages/reltuples statistics; but in any case this code is wrong on its
own terms, so fix it. Per report from Sergey Koposov.
Back-patch to 8.4, where the visibility map was introduced, same as the
previous change.
2011-08-30 20:49:45 +02:00
|
|
|
vacrelstats->old_rel_pages = onerel->rd_rel->relpages;
|
2009-06-07 00:13:52 +02:00
|
|
|
vacrelstats->old_rel_tuples = onerel->rd_rel->reltuples;
|
|
|
|
vacrelstats->num_index_scans = 0;
|
2007-04-18 18:44:18 +02:00
|
|
|
|
2001-07-14 00:55:59 +02:00
|
|
|
/* Open all indexes of the relation */
|
2006-07-31 22:09:10 +02:00
|
|
|
vac_open_indexes(onerel, RowExclusiveLock, &nindexes, &Irel);
|
2006-09-13 19:47:08 +02:00
|
|
|
vacrelstats->hasindex = (nindexes > 0);
|
2009-06-11 16:49:15 +02:00
|
|
|
|
2001-07-14 00:55:59 +02:00
|
|
|
/* Do the vacuuming */
|
2009-01-16 14:27:24 +01:00
|
|
|
lazy_scan_heap(onerel, vacrelstats, Irel, nindexes, scan_all);
|
2001-07-14 00:55:59 +02:00
|
|
|
|
|
|
|
/* Done with indexes */
|
2004-10-01 01:21:26 +02:00
|
|
|
vac_close_indexes(nindexes, Irel, NoLock);
|
2001-07-14 00:55:59 +02:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Optionally truncate the relation.
|
|
|
|
*
|
2001-10-25 07:50:21 +02:00
|
|
|
* Don't even think about it unless we have a shot at releasing a goodly
|
|
|
|
* number of pages. Otherwise, the time taken isn't worth it.
|
2001-07-14 00:55:59 +02:00
|
|
|
*/
|
|
|
|
possibly_freeable = vacrelstats->rel_pages - vacrelstats->nonempty_pages;
|
2009-01-06 15:55:37 +01:00
|
|
|
if (possibly_freeable > 0 &&
|
|
|
|
(possibly_freeable >= REL_TRUNCATE_MINIMUM ||
|
|
|
|
possibly_freeable >= vacrelstats->rel_pages / REL_TRUNCATE_FRACTION))
|
2010-02-09 22:43:30 +01:00
|
|
|
lazy_truncate_heap(onerel, vacrelstats);
|
|
|
|
|
|
|
|
/* Vacuum the Free Space Map */
|
|
|
|
FreeSpaceMapVacuum(onerel);
|
2007-02-21 23:15:21 +01:00
|
|
|
|
2008-12-03 14:05:22 +01:00
|
|
|
/*
|
Fix a missed case in code for "moving average" estimate of reltuples.
It is possible for VACUUM to scan no pages at all, if the visibility map
shows that all pages are all-visible. In this situation VACUUM has no new
information to report about the relation's tuple density, so it wasn't
changing pg_class.reltuples ... but it updated pg_class.relpages anyway.
That's wrong in general, since there is no evidence to justify changing the
density ratio reltuples/relpages, but it's particularly bad if the previous
state was relpages=reltuples=0, which means "unknown tuple density".
We just replaced "unknown" with "zero". ANALYZE would eventually recover
from this, but it could take a lot of repetitions of ANALYZE to do so if
the relation size is much larger than the maximum number of pages ANALYZE
will scan, because of the moving-average behavior introduced by commit
b4b6923e03f4d29636a94f6f4cc2f5cf6298b8c8.
The only known situation where we could have relpages=reltuples=0 and yet
the visibility map asserts everything's visible is immediately following
a pg_upgrade. It might be advisable for pg_upgrade to try to preserve the
relpages/reltuples statistics; but in any case this code is wrong on its
own terms, so fix it. Per report from Sergey Koposov.
Back-patch to 8.4, where the visibility map was introduced, same as the
previous change.
2011-08-30 20:49:45 +02:00
|
|
|
* Update statistics in pg_class.
|
|
|
|
*
|
|
|
|
* A corner case here is that if we scanned no pages at all because every
|
|
|
|
* page is all-visible, we should not update relpages/reltuples, because
|
|
|
|
* we have no new information to contribute. In particular this keeps
|
|
|
|
* us from replacing relpages=reltuples=0 (which means "unknown tuple
|
|
|
|
* density") with nonzero relpages and reltuples=0 (which means "zero
|
|
|
|
* tuple density") unless there's some actual evidence for the latter.
|
|
|
|
*
|
|
|
|
* Also, don't change relfrozenxid if we skipped any pages, since then
|
|
|
|
* we don't know for certain that all tuples have a newer xmin.
|
2008-12-03 14:05:22 +01:00
|
|
|
*/
|
Fix a missed case in code for "moving average" estimate of reltuples.
It is possible for VACUUM to scan no pages at all, if the visibility map
shows that all pages are all-visible. In this situation VACUUM has no new
information to report about the relation's tuple density, so it wasn't
changing pg_class.reltuples ... but it updated pg_class.relpages anyway.
That's wrong in general, since there is no evidence to justify changing the
density ratio reltuples/relpages, but it's particularly bad if the previous
state was relpages=reltuples=0, which means "unknown tuple density".
We just replaced "unknown" with "zero". ANALYZE would eventually recover
from this, but it could take a lot of repetitions of ANALYZE to do so if
the relation size is much larger than the maximum number of pages ANALYZE
will scan, because of the moving-average behavior introduced by commit
b4b6923e03f4d29636a94f6f4cc2f5cf6298b8c8.
The only known situation where we could have relpages=reltuples=0 and yet
the visibility map asserts everything's visible is immediately following
a pg_upgrade. It might be advisable for pg_upgrade to try to preserve the
relpages/reltuples statistics; but in any case this code is wrong on its
own terms, so fix it. Per report from Sergey Koposov.
Back-patch to 8.4, where the visibility map was introduced, same as the
previous change.
2011-08-30 20:49:45 +02:00
|
|
|
new_rel_pages = vacrelstats->rel_pages;
|
|
|
|
new_rel_tuples = vacrelstats->new_rel_tuples;
|
|
|
|
if (vacrelstats->scanned_pages == 0 && new_rel_pages > 0)
|
|
|
|
{
|
|
|
|
new_rel_pages = vacrelstats->old_rel_pages;
|
|
|
|
new_rel_tuples = vacrelstats->old_rel_tuples;
|
|
|
|
}
|
|
|
|
|
|
|
|
new_frozen_xid = FreezeLimit;
|
|
|
|
if (vacrelstats->scanned_pages < vacrelstats->rel_pages)
|
|
|
|
new_frozen_xid = InvalidTransactionId;
|
|
|
|
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
vac_update_relstats(onerel,
|
Fix a missed case in code for "moving average" estimate of reltuples.
It is possible for VACUUM to scan no pages at all, if the visibility map
shows that all pages are all-visible. In this situation VACUUM has no new
information to report about the relation's tuple density, so it wasn't
changing pg_class.reltuples ... but it updated pg_class.relpages anyway.
That's wrong in general, since there is no evidence to justify changing the
density ratio reltuples/relpages, but it's particularly bad if the previous
state was relpages=reltuples=0, which means "unknown tuple density".
We just replaced "unknown" with "zero". ANALYZE would eventually recover
from this, but it could take a lot of repetitions of ANALYZE to do so if
the relation size is much larger than the maximum number of pages ANALYZE
will scan, because of the moving-average behavior introduced by commit
b4b6923e03f4d29636a94f6f4cc2f5cf6298b8c8.
The only known situation where we could have relpages=reltuples=0 and yet
the visibility map asserts everything's visible is immediately following
a pg_upgrade. It might be advisable for pg_upgrade to try to preserve the
relpages/reltuples statistics; but in any case this code is wrong on its
own terms, so fix it. Per report from Sergey Koposov.
Back-patch to 8.4, where the visibility map was introduced, same as the
previous change.
2011-08-30 20:49:45 +02:00
|
|
|
new_rel_pages, new_rel_tuples,
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
vacrelstats->hasindex,
|
Fix a missed case in code for "moving average" estimate of reltuples.
It is possible for VACUUM to scan no pages at all, if the visibility map
shows that all pages are all-visible. In this situation VACUUM has no new
information to report about the relation's tuple density, so it wasn't
changing pg_class.reltuples ... but it updated pg_class.relpages anyway.
That's wrong in general, since there is no evidence to justify changing the
density ratio reltuples/relpages, but it's particularly bad if the previous
state was relpages=reltuples=0, which means "unknown tuple density".
We just replaced "unknown" with "zero". ANALYZE would eventually recover
from this, but it could take a lot of repetitions of ANALYZE to do so if
the relation size is much larger than the maximum number of pages ANALYZE
will scan, because of the moving-average behavior introduced by commit
b4b6923e03f4d29636a94f6f4cc2f5cf6298b8c8.
The only known situation where we could have relpages=reltuples=0 and yet
the visibility map asserts everything's visible is immediately following
a pg_upgrade. It might be advisable for pg_upgrade to try to preserve the
relpages/reltuples statistics; but in any case this code is wrong on its
own terms, so fix it. Per report from Sergey Koposov.
Back-patch to 8.4, where the visibility map was introduced, same as the
previous change.
2011-08-30 20:49:45 +02:00
|
|
|
new_frozen_xid);
|
2005-07-14 07:13:45 +02:00
|
|
|
|
|
|
|
/* report results to the stats collector, too */
|
2008-12-17 10:15:03 +01:00
|
|
|
pgstat_report_vacuum(RelationGetRelid(onerel),
|
|
|
|
onerel->rd_rel->relisshared,
|
Fix a missed case in code for "moving average" estimate of reltuples.
It is possible for VACUUM to scan no pages at all, if the visibility map
shows that all pages are all-visible. In this situation VACUUM has no new
information to report about the relation's tuple density, so it wasn't
changing pg_class.reltuples ... but it updated pg_class.relpages anyway.
That's wrong in general, since there is no evidence to justify changing the
density ratio reltuples/relpages, but it's particularly bad if the previous
state was relpages=reltuples=0, which means "unknown tuple density".
We just replaced "unknown" with "zero". ANALYZE would eventually recover
from this, but it could take a lot of repetitions of ANALYZE to do so if
the relation size is much larger than the maximum number of pages ANALYZE
will scan, because of the moving-average behavior introduced by commit
b4b6923e03f4d29636a94f6f4cc2f5cf6298b8c8.
The only known situation where we could have relpages=reltuples=0 and yet
the visibility map asserts everything's visible is immediately following
a pg_upgrade. It might be advisable for pg_upgrade to try to preserve the
relpages/reltuples statistics; but in any case this code is wrong on its
own terms, so fix it. Per report from Sergey Koposov.
Back-patch to 8.4, where the visibility map was introduced, same as the
previous change.
2011-08-30 20:49:45 +02:00
|
|
|
new_rel_tuples);
|
2007-04-18 18:44:18 +02:00
|
|
|
|
|
|
|
/* and log the action if appropriate */
|
2007-09-24 05:12:23 +02:00
|
|
|
if (IsAutoVacuumWorkerProcess() && Log_autovacuum_min_duration >= 0)
|
2007-04-18 18:44:18 +02:00
|
|
|
{
|
2007-09-24 05:12:23 +02:00
|
|
|
if (Log_autovacuum_min_duration == 0 ||
|
2007-04-30 05:23:49 +02:00
|
|
|
TimestampDifferenceExceeds(starttime, GetCurrentTimestamp(),
|
2007-09-24 05:12:23 +02:00
|
|
|
Log_autovacuum_min_duration))
|
2007-04-18 18:44:18 +02:00
|
|
|
ereport(LOG,
|
|
|
|
(errmsg("automatic vacuum of table \"%s.%s.%s\": index scans: %d\n"
|
|
|
|
"pages: %d removed, %d remain\n"
|
|
|
|
"tuples: %.0f removed, %.0f remain\n"
|
|
|
|
"system usage: %s",
|
|
|
|
get_database_name(MyDatabaseId),
|
|
|
|
get_namespace_name(RelationGetNamespace(onerel)),
|
|
|
|
RelationGetRelationName(onerel),
|
|
|
|
vacrelstats->num_index_scans,
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
vacrelstats->pages_removed,
|
|
|
|
vacrelstats->rel_pages,
|
|
|
|
vacrelstats->tuples_deleted,
|
Fix a missed case in code for "moving average" estimate of reltuples.
It is possible for VACUUM to scan no pages at all, if the visibility map
shows that all pages are all-visible. In this situation VACUUM has no new
information to report about the relation's tuple density, so it wasn't
changing pg_class.reltuples ... but it updated pg_class.relpages anyway.
That's wrong in general, since there is no evidence to justify changing the
density ratio reltuples/relpages, but it's particularly bad if the previous
state was relpages=reltuples=0, which means "unknown tuple density".
We just replaced "unknown" with "zero". ANALYZE would eventually recover
from this, but it could take a lot of repetitions of ANALYZE to do so if
the relation size is much larger than the maximum number of pages ANALYZE
will scan, because of the moving-average behavior introduced by commit
b4b6923e03f4d29636a94f6f4cc2f5cf6298b8c8.
The only known situation where we could have relpages=reltuples=0 and yet
the visibility map asserts everything's visible is immediately following
a pg_upgrade. It might be advisable for pg_upgrade to try to preserve the
relpages/reltuples statistics; but in any case this code is wrong on its
own terms, so fix it. Per report from Sergey Koposov.
Back-patch to 8.4, where the visibility map was introduced, same as the
previous change.
2011-08-30 20:49:45 +02:00
|
|
|
new_rel_tuples,
|
2007-04-18 18:44:18 +02:00
|
|
|
pg_rusage_show(&ru0))));
|
|
|
|
}
|
2001-07-14 00:55:59 +02:00
|
|
|
}
|
|
|
|
|
Allow read only connections during recovery, known as Hot Standby.
Enabled by recovery_connections = on (default) and forcing archive recovery using a recovery.conf. Recovery processing now emulates the original transactions as they are replayed, providing full locking and MVCC behaviour for read only queries. Recovery must enter consistent state before connections are allowed, so there is a delay, typically short, before connections succeed. Replay of recovering transactions can conflict and in some cases deadlock with queries during recovery; these result in query cancellation after max_standby_delay seconds have expired. Infrastructure changes have minor effects on normal running, though introduce four new types of WAL record.
New test mode "make standbycheck" allows regression tests of static command behaviour on a standby server while in recovery. Typical and extreme dynamic behaviours have been checked via code inspection and manual testing. Few port specific behaviours have been utilised, though primary testing has been on Linux only so far.
This commit is the basic patch. Additional changes will follow in this release to enhance some aspects of behaviour, notably improved handling of conflicts, deadlock detection and query cancellation. Changes to VACUUM FULL are also required.
Simon Riggs, with significant and lengthy review by Heikki Linnakangas, including streamlined redesign of snapshot creation and two-phase commit.
Important contributions from Florian Pflug, Mark Kirkwood, Merlin Moncure, Greg Stark, Gianni Ciolli, Gabriele Bartolini, Hannu Krosing, Robert Haas, Tatsuo Ishii, Hiroyuki Yamada plus support and feedback from many other community members.
2009-12-19 02:32:45 +01:00
|
|
|
/*
|
|
|
|
* For Hot Standby we need to know the highest transaction id that will
|
|
|
|
* be removed by any change. VACUUM proceeds in a number of passes so
|
|
|
|
* we need to consider how each pass operates. The first phase runs
|
|
|
|
* heap_page_prune(), which can issue XLOG_HEAP2_CLEAN records as it
|
|
|
|
* progresses - these will have a latestRemovedXid on each record.
|
|
|
|
* In some cases this removes all of the tuples to be removed, though
|
|
|
|
* often we have dead tuples with index pointers so we must remember them
|
|
|
|
* for removal in phase 3. Index records for those rows are removed
|
|
|
|
* in phase 2 and index blocks do not have MVCC information attached.
|
|
|
|
* So before we can allow removal of any index tuples we need to issue
|
|
|
|
* a WAL record containing the latestRemovedXid of rows that will be
|
|
|
|
* removed in phase three. This allows recovery queries to block at the
|
|
|
|
* correct place, i.e. before phase two, rather than during phase three
|
|
|
|
* which would be after the rows have become inaccessible.
|
|
|
|
*/
|
|
|
|
static void
|
|
|
|
vacuum_log_cleanup_info(Relation rel, LVRelStats *vacrelstats)
|
|
|
|
{
|
|
|
|
/*
|
2010-12-13 18:34:26 +01:00
|
|
|
* Skip this for relations for which no WAL is to be written, or if we're
|
|
|
|
* not trying to support archive recovery.
|
Allow read only connections during recovery, known as Hot Standby.
Enabled by recovery_connections = on (default) and forcing archive recovery using a recovery.conf. Recovery processing now emulates the original transactions as they are replayed, providing full locking and MVCC behaviour for read only queries. Recovery must enter consistent state before connections are allowed, so there is a delay, typically short, before connections succeed. Replay of recovering transactions can conflict and in some cases deadlock with queries during recovery; these result in query cancellation after max_standby_delay seconds have expired. Infrastructure changes have minor effects on normal running, though introduce four new types of WAL record.
New test mode "make standbycheck" allows regression tests of static command behaviour on a standby server while in recovery. Typical and extreme dynamic behaviours have been checked via code inspection and manual testing. Few port specific behaviours have been utilised, though primary testing has been on Linux only so far.
This commit is the basic patch. Additional changes will follow in this release to enhance some aspects of behaviour, notably improved handling of conflicts, deadlock detection and query cancellation. Changes to VACUUM FULL are also required.
Simon Riggs, with significant and lengthy review by Heikki Linnakangas, including streamlined redesign of snapshot creation and two-phase commit.
Important contributions from Florian Pflug, Mark Kirkwood, Merlin Moncure, Greg Stark, Gianni Ciolli, Gabriele Bartolini, Hannu Krosing, Robert Haas, Tatsuo Ishii, Hiroyuki Yamada plus support and feedback from many other community members.
2009-12-19 02:32:45 +01:00
|
|
|
*/
|
2010-12-13 18:34:26 +01:00
|
|
|
if (!RelationNeedsWAL(rel) || !XLogIsNeeded())
|
Allow read only connections during recovery, known as Hot Standby.
Enabled by recovery_connections = on (default) and forcing archive recovery using a recovery.conf. Recovery processing now emulates the original transactions as they are replayed, providing full locking and MVCC behaviour for read only queries. Recovery must enter consistent state before connections are allowed, so there is a delay, typically short, before connections succeed. Replay of recovering transactions can conflict and in some cases deadlock with queries during recovery; these result in query cancellation after max_standby_delay seconds have expired. Infrastructure changes have minor effects on normal running, though introduce four new types of WAL record.
New test mode "make standbycheck" allows regression tests of static command behaviour on a standby server while in recovery. Typical and extreme dynamic behaviours have been checked via code inspection and manual testing. Few port specific behaviours have been utilised, though primary testing has been on Linux only so far.
This commit is the basic patch. Additional changes will follow in this release to enhance some aspects of behaviour, notably improved handling of conflicts, deadlock detection and query cancellation. Changes to VACUUM FULL are also required.
Simon Riggs, with significant and lengthy review by Heikki Linnakangas, including streamlined redesign of snapshot creation and two-phase commit.
Important contributions from Florian Pflug, Mark Kirkwood, Merlin Moncure, Greg Stark, Gianni Ciolli, Gabriele Bartolini, Hannu Krosing, Robert Haas, Tatsuo Ishii, Hiroyuki Yamada plus support and feedback from many other community members.
2009-12-19 02:32:45 +01:00
|
|
|
return;
|
|
|
|
|
2010-04-22 04:15:45 +02:00
|
|
|
/*
|
|
|
|
* No need to write the record at all unless it contains a valid value
|
|
|
|
*/
|
|
|
|
if (TransactionIdIsValid(vacrelstats->latestRemovedXid))
|
2010-04-21 21:53:24 +02:00
|
|
|
(void) log_heap_cleanup_info(rel->rd_node, vacrelstats->latestRemovedXid);
|
Allow read only connections during recovery, known as Hot Standby.
Enabled by recovery_connections = on (default) and forcing archive recovery using a recovery.conf. Recovery processing now emulates the original transactions as they are replayed, providing full locking and MVCC behaviour for read only queries. Recovery must enter consistent state before connections are allowed, so there is a delay, typically short, before connections succeed. Replay of recovering transactions can conflict and in some cases deadlock with queries during recovery; these result in query cancellation after max_standby_delay seconds have expired. Infrastructure changes have minor effects on normal running, though introduce four new types of WAL record.
New test mode "make standbycheck" allows regression tests of static command behaviour on a standby server while in recovery. Typical and extreme dynamic behaviours have been checked via code inspection and manual testing. Few port specific behaviours have been utilised, though primary testing has been on Linux only so far.
This commit is the basic patch. Additional changes will follow in this release to enhance some aspects of behaviour, notably improved handling of conflicts, deadlock detection and query cancellation. Changes to VACUUM FULL are also required.
Simon Riggs, with significant and lengthy review by Heikki Linnakangas, including streamlined redesign of snapshot creation and two-phase commit.
Important contributions from Florian Pflug, Mark Kirkwood, Merlin Moncure, Greg Stark, Gianni Ciolli, Gabriele Bartolini, Hannu Krosing, Robert Haas, Tatsuo Ishii, Hiroyuki Yamada plus support and feedback from many other community members.
2009-12-19 02:32:45 +01:00
|
|
|
}
|
2001-07-14 00:55:59 +02:00
|
|
|
|
|
|
|
/*
|
|
|
|
* lazy_scan_heap() -- scan an open heap relation
|
|
|
|
*
|
|
|
|
* This routine sets commit status bits, builds lists of dead tuples
|
|
|
|
* and pages with free space, and calculates statistics on the number
|
|
|
|
* of live tuples in the heap. When done, or when we run low on space
|
2006-09-13 19:47:08 +02:00
|
|
|
* for dead-tuple TIDs, invoke vacuuming of indexes and heap.
|
2006-07-10 18:20:52 +02:00
|
|
|
*
|
2006-09-13 19:47:08 +02:00
|
|
|
* If there are no indexes then we just vacuum each dirty page as we
|
|
|
|
* process it, since there's no point in gathering many tuples.
|
2001-07-14 00:55:59 +02:00
|
|
|
*/
|
|
|
|
static void
|
|
|
|
lazy_scan_heap(Relation onerel, LVRelStats *vacrelstats,
|
2008-12-03 14:05:22 +01:00
|
|
|
Relation *Irel, int nindexes, bool scan_all)
|
2001-07-14 00:55:59 +02:00
|
|
|
{
|
|
|
|
BlockNumber nblocks,
|
|
|
|
blkno;
|
|
|
|
HeapTupleData tuple;
|
|
|
|
char *relname;
|
2006-09-13 19:47:08 +02:00
|
|
|
BlockNumber empty_pages,
|
|
|
|
vacuumed_pages;
|
2001-07-14 00:55:59 +02:00
|
|
|
double num_tuples,
|
|
|
|
tups_vacuumed,
|
|
|
|
nkeep,
|
|
|
|
nunused;
|
2006-05-03 00:25:10 +02:00
|
|
|
IndexBulkDeleteResult **indstats;
|
2001-07-14 00:55:59 +02:00
|
|
|
int i;
|
2005-10-04 00:52:26 +02:00
|
|
|
PGRUsage ru0;
|
2008-12-03 14:05:22 +01:00
|
|
|
Buffer vmbuffer = InvalidBuffer;
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
BlockNumber next_not_all_visible_block;
|
|
|
|
bool skipping_all_visible_blocks;
|
2001-07-14 00:55:59 +02:00
|
|
|
|
2005-10-04 00:52:26 +02:00
|
|
|
pg_rusage_init(&ru0);
|
2001-07-14 00:55:59 +02:00
|
|
|
|
|
|
|
relname = RelationGetRelationName(onerel);
|
2003-07-20 23:56:35 +02:00
|
|
|
ereport(elevel,
|
|
|
|
(errmsg("vacuuming \"%s.%s\"",
|
|
|
|
get_namespace_name(RelationGetNamespace(onerel)),
|
|
|
|
relname)));
|
2001-07-14 00:55:59 +02:00
|
|
|
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
empty_pages = vacuumed_pages = 0;
|
2001-07-14 00:55:59 +02:00
|
|
|
num_tuples = tups_vacuumed = nkeep = nunused = 0;
|
|
|
|
|
2006-05-03 00:25:10 +02:00
|
|
|
indstats = (IndexBulkDeleteResult **)
|
|
|
|
palloc0(nindexes * sizeof(IndexBulkDeleteResult *));
|
2004-12-01 20:00:56 +01:00
|
|
|
|
2001-07-14 00:55:59 +02:00
|
|
|
nblocks = RelationGetNumberOfBlocks(onerel);
|
|
|
|
vacrelstats->rel_pages = nblocks;
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
vacrelstats->scanned_pages = 0;
|
2001-07-14 00:55:59 +02:00
|
|
|
vacrelstats->nonempty_pages = 0;
|
Allow read only connections during recovery, known as Hot Standby.
Enabled by recovery_connections = on (default) and forcing archive recovery using a recovery.conf. Recovery processing now emulates the original transactions as they are replayed, providing full locking and MVCC behaviour for read only queries. Recovery must enter consistent state before connections are allowed, so there is a delay, typically short, before connections succeed. Replay of recovering transactions can conflict and in some cases deadlock with queries during recovery; these result in query cancellation after max_standby_delay seconds have expired. Infrastructure changes have minor effects on normal running, though introduce four new types of WAL record.
New test mode "make standbycheck" allows regression tests of static command behaviour on a standby server while in recovery. Typical and extreme dynamic behaviours have been checked via code inspection and manual testing. Few port specific behaviours have been utilised, though primary testing has been on Linux only so far.
This commit is the basic patch. Additional changes will follow in this release to enhance some aspects of behaviour, notably improved handling of conflicts, deadlock detection and query cancellation. Changes to VACUUM FULL are also required.
Simon Riggs, with significant and lengthy review by Heikki Linnakangas, including streamlined redesign of snapshot creation and two-phase commit.
Important contributions from Florian Pflug, Mark Kirkwood, Merlin Moncure, Greg Stark, Gianni Ciolli, Gabriele Bartolini, Hannu Krosing, Robert Haas, Tatsuo Ishii, Hiroyuki Yamada plus support and feedback from many other community members.
2009-12-19 02:32:45 +01:00
|
|
|
vacrelstats->latestRemovedXid = InvalidTransactionId;
|
2001-07-14 00:55:59 +02:00
|
|
|
|
2006-09-13 19:47:08 +02:00
|
|
|
lazy_space_alloc(vacrelstats, nblocks);
|
2001-07-14 00:55:59 +02:00
|
|
|
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
/*
|
|
|
|
* We want to skip pages that don't require vacuuming according to the
|
|
|
|
* visibility map, but only when we can skip at least SKIP_PAGES_THRESHOLD
|
|
|
|
* consecutive pages. Since we're reading sequentially, the OS should be
|
|
|
|
* doing readahead for us, so there's no gain in skipping a page now and
|
|
|
|
* then; that's likely to disable readahead and so be counterproductive.
|
|
|
|
* Also, skipping even a single page means that we can't update
|
|
|
|
* relfrozenxid, so we only want to do it if we can skip a goodly number
|
|
|
|
* of pages.
|
|
|
|
*
|
|
|
|
* Before entering the main loop, establish the invariant that
|
2011-06-09 20:32:50 +02:00
|
|
|
* next_not_all_visible_block is the next block number >= blkno that's not
|
|
|
|
* all-visible according to the visibility map, or nblocks if there's no
|
|
|
|
* such block. Also, we set up the skipping_all_visible_blocks flag,
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
* which is needed because we need hysteresis in the decision: once we've
|
|
|
|
* started skipping blocks, we may as well skip everything up to the next
|
|
|
|
* not-all-visible block.
|
|
|
|
*
|
|
|
|
* Note: if scan_all is true, we won't actually skip any pages; but we
|
|
|
|
* maintain next_not_all_visible_block anyway, so as to set up the
|
|
|
|
* all_visible_according_to_vm flag correctly for each page.
|
|
|
|
*/
|
|
|
|
for (next_not_all_visible_block = 0;
|
|
|
|
next_not_all_visible_block < nblocks;
|
|
|
|
next_not_all_visible_block++)
|
|
|
|
{
|
|
|
|
if (!visibilitymap_test(onerel, next_not_all_visible_block, &vmbuffer))
|
|
|
|
break;
|
|
|
|
vacuum_delay_point();
|
|
|
|
}
|
|
|
|
if (next_not_all_visible_block >= SKIP_PAGES_THRESHOLD)
|
|
|
|
skipping_all_visible_blocks = true;
|
|
|
|
else
|
|
|
|
skipping_all_visible_blocks = false;
|
|
|
|
|
2001-07-14 00:55:59 +02:00
|
|
|
for (blkno = 0; blkno < nblocks; blkno++)
|
|
|
|
{
|
|
|
|
Buffer buf;
|
|
|
|
Page page;
|
|
|
|
OffsetNumber offnum,
|
|
|
|
maxoff;
|
Fix recently-understood problems with handling of XID freezing, particularly
in PITR scenarios. We now WAL-log the replacement of old XIDs with
FrozenTransactionId, so that such replacement is guaranteed to propagate to
PITR slave databases. Also, rather than relying on hint-bit updates to be
preserved, pg_clog is not truncated until all instances of an XID are known to
have been replaced by FrozenTransactionId. Add new GUC variables and
pg_autovacuum columns to allow management of the freezing policy, so that
users can trade off the size of pg_clog against the amount of freezing work
done. Revise the already-existing code that forces autovacuum of tables
approaching the wraparound point to make it more bulletproof; also, revise the
autovacuum logic so that anti-wraparound vacuuming is done per-table rather
than per-database. initdb forced because of changes in pg_class, pg_database,
and pg_autovacuum catalogs. Heikki Linnakangas, Simon Riggs, and Tom Lane.
2006-11-05 23:42:10 +01:00
|
|
|
bool tupgone,
|
2001-07-14 00:55:59 +02:00
|
|
|
hastup;
|
|
|
|
int prev_dead_count;
|
Fix recently-understood problems with handling of XID freezing, particularly
in PITR scenarios. We now WAL-log the replacement of old XIDs with
FrozenTransactionId, so that such replacement is guaranteed to propagate to
PITR slave databases. Also, rather than relying on hint-bit updates to be
preserved, pg_clog is not truncated until all instances of an XID are known to
have been replaced by FrozenTransactionId. Add new GUC variables and
pg_autovacuum columns to allow management of the freezing policy, so that
users can trade off the size of pg_clog against the amount of freezing work
done. Revise the already-existing code that forces autovacuum of tables
approaching the wraparound point to make it more bulletproof; also, revise the
autovacuum logic so that anti-wraparound vacuuming is done per-table rather
than per-database. initdb forced because of changes in pg_class, pg_database,
and pg_autovacuum catalogs. Heikki Linnakangas, Simon Riggs, and Tom Lane.
2006-11-05 23:42:10 +01:00
|
|
|
OffsetNumber frozen[MaxOffsetNumber];
|
|
|
|
int nfrozen;
|
2008-09-30 12:52:14 +02:00
|
|
|
Size freespace;
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
bool all_visible_according_to_vm;
|
2008-12-03 14:05:22 +01:00
|
|
|
bool all_visible;
|
2011-03-08 19:13:52 +01:00
|
|
|
bool has_dead_tuples;
|
2008-12-03 14:05:22 +01:00
|
|
|
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
if (blkno == next_not_all_visible_block)
|
2008-12-03 14:05:22 +01:00
|
|
|
{
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
/* Time to advance next_not_all_visible_block */
|
|
|
|
for (next_not_all_visible_block++;
|
|
|
|
next_not_all_visible_block < nblocks;
|
|
|
|
next_not_all_visible_block++)
|
2008-12-03 14:05:22 +01:00
|
|
|
{
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
if (!visibilitymap_test(onerel, next_not_all_visible_block,
|
|
|
|
&vmbuffer))
|
|
|
|
break;
|
|
|
|
vacuum_delay_point();
|
2008-12-03 14:05:22 +01:00
|
|
|
}
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
|
|
|
|
/*
|
|
|
|
* We know we can't skip the current block. But set up
|
|
|
|
* skipping_all_visible_blocks to do the right thing at the
|
|
|
|
* following blocks.
|
|
|
|
*/
|
|
|
|
if (next_not_all_visible_block - blkno > SKIP_PAGES_THRESHOLD)
|
|
|
|
skipping_all_visible_blocks = true;
|
2009-01-22 20:25:00 +01:00
|
|
|
else
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
skipping_all_visible_blocks = false;
|
|
|
|
all_visible_according_to_vm = false;
|
|
|
|
}
|
|
|
|
else
|
|
|
|
{
|
|
|
|
/* Current block is all-visible */
|
|
|
|
if (skipping_all_visible_blocks && !scan_all)
|
|
|
|
continue;
|
|
|
|
all_visible_according_to_vm = true;
|
2008-12-03 14:05:22 +01:00
|
|
|
}
|
2001-07-14 00:55:59 +02:00
|
|
|
|
2004-02-10 04:42:45 +01:00
|
|
|
vacuum_delay_point();
|
2004-02-06 20:36:18 +01:00
|
|
|
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
vacrelstats->scanned_pages++;
|
2008-12-03 14:05:22 +01:00
|
|
|
|
2001-07-14 00:55:59 +02:00
|
|
|
/*
|
2005-10-15 04:49:52 +02:00
|
|
|
* If we are close to overrunning the available space for dead-tuple
|
|
|
|
* TIDs, pause and do a cycle of vacuuming before we tackle this page.
|
2001-07-14 00:55:59 +02:00
|
|
|
*/
|
2005-09-02 21:02:20 +02:00
|
|
|
if ((vacrelstats->max_dead_tuples - vacrelstats->num_dead_tuples) < MaxHeapTuplesPerPage &&
|
2001-07-14 00:55:59 +02:00
|
|
|
vacrelstats->num_dead_tuples > 0)
|
|
|
|
{
|
Allow read only connections during recovery, known as Hot Standby.
Enabled by recovery_connections = on (default) and forcing archive recovery using a recovery.conf. Recovery processing now emulates the original transactions as they are replayed, providing full locking and MVCC behaviour for read only queries. Recovery must enter consistent state before connections are allowed, so there is a delay, typically short, before connections succeed. Replay of recovering transactions can conflict and in some cases deadlock with queries during recovery; these result in query cancellation after max_standby_delay seconds have expired. Infrastructure changes have minor effects on normal running, though introduce four new types of WAL record.
New test mode "make standbycheck" allows regression tests of static command behaviour on a standby server while in recovery. Typical and extreme dynamic behaviours have been checked via code inspection and manual testing. Few port specific behaviours have been utilised, though primary testing has been on Linux only so far.
This commit is the basic patch. Additional changes will follow in this release to enhance some aspects of behaviour, notably improved handling of conflicts, deadlock detection and query cancellation. Changes to VACUUM FULL are also required.
Simon Riggs, with significant and lengthy review by Heikki Linnakangas, including streamlined redesign of snapshot creation and two-phase commit.
Important contributions from Florian Pflug, Mark Kirkwood, Merlin Moncure, Greg Stark, Gianni Ciolli, Gabriele Bartolini, Hannu Krosing, Robert Haas, Tatsuo Ishii, Hiroyuki Yamada plus support and feedback from many other community members.
2009-12-19 02:32:45 +01:00
|
|
|
/* Log cleanup info before we touch indexes */
|
|
|
|
vacuum_log_cleanup_info(onerel, vacrelstats);
|
|
|
|
|
2001-07-14 00:55:59 +02:00
|
|
|
/* Remove index entries */
|
|
|
|
for (i = 0; i < nindexes; i++)
|
2004-12-01 20:00:56 +01:00
|
|
|
lazy_vacuum_index(Irel[i],
|
2006-05-03 00:25:10 +02:00
|
|
|
&indstats[i],
|
2004-12-01 20:00:56 +01:00
|
|
|
vacrelstats);
|
2001-07-14 00:55:59 +02:00
|
|
|
/* Remove tuples from heap */
|
|
|
|
lazy_vacuum_heap(onerel, vacrelstats);
|
2010-07-06 21:19:02 +02:00
|
|
|
|
2010-04-21 19:20:56 +02:00
|
|
|
/*
|
|
|
|
* Forget the now-vacuumed tuples, and press on, but be careful
|
2010-07-06 21:19:02 +02:00
|
|
|
* not to reset latestRemovedXid since we want that value to be
|
|
|
|
* valid.
|
2010-04-21 19:20:56 +02:00
|
|
|
*/
|
2001-07-14 00:55:59 +02:00
|
|
|
vacrelstats->num_dead_tuples = 0;
|
2007-04-18 18:44:18 +02:00
|
|
|
vacrelstats->num_index_scans++;
|
2001-07-14 00:55:59 +02:00
|
|
|
}
|
|
|
|
|
Unite ReadBufferWithFork, ReadBufferWithStrategy, and ZeroOrReadBuffer
functions into one ReadBufferExtended function, that takes the strategy
and mode as argument. There's three modes, RBM_NORMAL which is the default
used by plain ReadBuffer(), RBM_ZERO, which replaces ZeroOrReadBuffer, and
a new mode RBM_ZERO_ON_ERROR, which allows callers to read corrupt pages
without throwing an error. The FSM needs the new mode to recover from
corrupt pages, which could happend if we crash after extending an FSM file,
and the new page is "torn".
Add fork number to some error messages in bufmgr.c, that still lacked it.
2008-10-31 16:05:00 +01:00
|
|
|
buf = ReadBufferExtended(onerel, MAIN_FORKNUM, blkno,
|
|
|
|
RBM_NORMAL, vac_strategy);
|
2001-07-14 00:55:59 +02:00
|
|
|
|
2007-09-20 19:56:33 +02:00
|
|
|
/* We need buffer cleanup lock so that we can prune HOT chains. */
|
|
|
|
LockBufferForCleanup(buf);
|
2001-07-14 00:55:59 +02:00
|
|
|
|
|
|
|
page = BufferGetPage(buf);
|
|
|
|
|
|
|
|
if (PageIsNew(page))
|
|
|
|
{
|
2005-05-07 23:32:24 +02:00
|
|
|
/*
|
2005-10-15 04:49:52 +02:00
|
|
|
* An all-zeroes page could be left over if a backend extends the
|
|
|
|
* relation but crashes before initializing the page. Reclaim such
|
|
|
|
* pages for use.
|
2005-05-07 23:32:24 +02:00
|
|
|
*
|
2005-11-22 19:17:34 +01:00
|
|
|
* We have to be careful here because we could be looking at a
|
|
|
|
* page that someone has just added to the relation and not yet
|
|
|
|
* been able to initialize (see RelationGetBufferForTuple). To
|
2007-09-20 19:56:33 +02:00
|
|
|
* protect against that, release the buffer lock, grab the
|
2007-11-15 22:14:46 +01:00
|
|
|
* relation extension lock momentarily, and re-lock the buffer. If
|
|
|
|
* the page is still uninitialized by then, it must be left over
|
|
|
|
* from a crashed backend, and we can initialize it.
|
2005-05-07 23:32:24 +02:00
|
|
|
*
|
2005-11-22 19:17:34 +01:00
|
|
|
* We don't really need the relation lock when this is a new or
|
|
|
|
* temp relation, but it's probably not worth the code space to
|
|
|
|
* check that, since this surely isn't a critical path.
|
2005-05-07 23:32:24 +02:00
|
|
|
*
|
2005-11-22 19:17:34 +01:00
|
|
|
* Note: the comparable code in vacuum.c need not worry because
|
|
|
|
* it's got exclusive lock on the whole relation.
|
2005-05-07 23:32:24 +02:00
|
|
|
*/
|
2001-07-14 00:55:59 +02:00
|
|
|
LockBuffer(buf, BUFFER_LOCK_UNLOCK);
|
2005-05-07 23:32:24 +02:00
|
|
|
LockRelationForExtension(onerel, ExclusiveLock);
|
|
|
|
UnlockRelationForExtension(onerel, ExclusiveLock);
|
2007-09-20 19:56:33 +02:00
|
|
|
LockBufferForCleanup(buf);
|
2001-07-14 00:55:59 +02:00
|
|
|
if (PageIsNew(page))
|
|
|
|
{
|
2003-07-20 23:56:35 +02:00
|
|
|
ereport(WARNING,
|
2005-10-15 04:49:52 +02:00
|
|
|
(errmsg("relation \"%s\" page %u is uninitialized --- fixing",
|
|
|
|
relname, blkno)));
|
2001-07-14 00:55:59 +02:00
|
|
|
PageInit(page, BufferGetPageSize(buf), 0);
|
2003-07-20 23:56:35 +02:00
|
|
|
empty_pages++;
|
2001-07-14 00:55:59 +02:00
|
|
|
}
|
2008-09-30 12:52:14 +02:00
|
|
|
freespace = PageGetHeapFreeSpace(page);
|
2006-04-01 01:32:07 +02:00
|
|
|
MarkBufferDirty(buf);
|
|
|
|
UnlockReleaseBuffer(buf);
|
2008-09-30 12:52:14 +02:00
|
|
|
|
|
|
|
RecordPageWithFreeSpace(onerel, blkno, freespace);
|
2001-07-14 00:55:59 +02:00
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (PageIsEmpty(page))
|
|
|
|
{
|
|
|
|
empty_pages++;
|
2008-09-30 12:52:14 +02:00
|
|
|
freespace = PageGetHeapFreeSpace(page);
|
2008-12-03 14:05:22 +01:00
|
|
|
|
|
|
|
if (!PageIsAllVisible(page))
|
|
|
|
{
|
|
|
|
PageSetAllVisible(page);
|
2009-08-24 04:18:32 +02:00
|
|
|
SetBufferCommitInfoNeedsSave(buf);
|
2008-12-03 14:05:22 +01:00
|
|
|
}
|
|
|
|
|
|
|
|
LockBuffer(buf, BUFFER_LOCK_UNLOCK);
|
|
|
|
|
|
|
|
/* Update the visibility map */
|
|
|
|
if (!all_visible_according_to_vm)
|
|
|
|
{
|
|
|
|
visibilitymap_pin(onerel, blkno, &vmbuffer);
|
|
|
|
LockBuffer(buf, BUFFER_LOCK_SHARE);
|
|
|
|
if (PageIsAllVisible(page))
|
Make the visibility map crash-safe.
This involves two main changes from the previous behavior. First,
when we set a bit in the visibility map, emit a new WAL record of type
XLOG_HEAP2_VISIBLE. Replay sets the page-level PD_ALL_VISIBLE bit and
the visibility map bit. Second, when inserting, updating, or deleting
a tuple, we can no longer get away with clearing the visibility map
bit after releasing the lock on the corresponding heap page, because
an intervening crash might leave the visibility map bit set and the
page-level bit clear. Making this work requires a bit of interface
refactoring.
In passing, a few minor but related cleanups: change the test in
visibilitymap_set and visibilitymap_clear to throw an error if the
wrong page (or no page) is pinned, rather than silently doing nothing;
this case should never occur. Also, remove duplicate definitions of
InvalidXLogRecPtr.
Patch by me, review by Noah Misch.
2011-06-22 05:04:40 +02:00
|
|
|
visibilitymap_set(onerel, blkno, InvalidXLogRecPtr,
|
|
|
|
vmbuffer);
|
2008-12-03 14:05:22 +01:00
|
|
|
LockBuffer(buf, BUFFER_LOCK_UNLOCK);
|
|
|
|
}
|
|
|
|
|
|
|
|
ReleaseBuffer(buf);
|
2008-09-30 12:52:14 +02:00
|
|
|
RecordPageWithFreeSpace(onerel, blkno, freespace);
|
2001-07-14 00:55:59 +02:00
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
2007-11-15 22:14:46 +01:00
|
|
|
/*
|
2007-09-20 19:56:33 +02:00
|
|
|
* Prune all HOT-update chains in this page.
|
|
|
|
*
|
|
|
|
* We count tuples removed by the pruning step as removed by VACUUM.
|
|
|
|
*/
|
2010-04-21 19:20:56 +02:00
|
|
|
tups_vacuumed += heap_page_prune(onerel, buf, OldestXmin, false,
|
2010-07-06 21:19:02 +02:00
|
|
|
&vacrelstats->latestRemovedXid);
|
|
|
|
|
2007-09-20 19:56:33 +02:00
|
|
|
/*
|
2007-11-15 22:14:46 +01:00
|
|
|
* Now scan the page to collect vacuumable items and check for tuples
|
|
|
|
* requiring freezing.
|
2007-09-20 19:56:33 +02:00
|
|
|
*/
|
2008-12-03 14:05:22 +01:00
|
|
|
all_visible = true;
|
2011-03-08 19:13:52 +01:00
|
|
|
has_dead_tuples = false;
|
Fix recently-understood problems with handling of XID freezing, particularly
in PITR scenarios. We now WAL-log the replacement of old XIDs with
FrozenTransactionId, so that such replacement is guaranteed to propagate to
PITR slave databases. Also, rather than relying on hint-bit updates to be
preserved, pg_clog is not truncated until all instances of an XID are known to
have been replaced by FrozenTransactionId. Add new GUC variables and
pg_autovacuum columns to allow management of the freezing policy, so that
users can trade off the size of pg_clog against the amount of freezing work
done. Revise the already-existing code that forces autovacuum of tables
approaching the wraparound point to make it more bulletproof; also, revise the
autovacuum logic so that anti-wraparound vacuuming is done per-table rather
than per-database. initdb forced because of changes in pg_class, pg_database,
and pg_autovacuum catalogs. Heikki Linnakangas, Simon Riggs, and Tom Lane.
2006-11-05 23:42:10 +01:00
|
|
|
nfrozen = 0;
|
2001-07-14 00:55:59 +02:00
|
|
|
hastup = false;
|
|
|
|
prev_dead_count = vacrelstats->num_dead_tuples;
|
|
|
|
maxoff = PageGetMaxOffsetNumber(page);
|
|
|
|
for (offnum = FirstOffsetNumber;
|
|
|
|
offnum <= maxoff;
|
|
|
|
offnum = OffsetNumberNext(offnum))
|
|
|
|
{
|
|
|
|
ItemId itemid;
|
|
|
|
|
|
|
|
itemid = PageGetItemId(page, offnum);
|
|
|
|
|
2007-09-20 19:56:33 +02:00
|
|
|
/* Unused items require no processing, but we count 'em */
|
2001-07-14 00:55:59 +02:00
|
|
|
if (!ItemIdIsUsed(itemid))
|
|
|
|
{
|
|
|
|
nunused += 1;
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
2007-09-20 19:56:33 +02:00
|
|
|
/* Redirect items mustn't be touched */
|
2007-11-15 22:14:46 +01:00
|
|
|
if (ItemIdIsRedirected(itemid))
|
|
|
|
{
|
2007-09-20 19:56:33 +02:00
|
|
|
hastup = true; /* this page won't be truncatable */
|
2007-11-15 22:14:46 +01:00
|
|
|
continue;
|
|
|
|
}
|
2007-09-20 19:56:33 +02:00
|
|
|
|
2007-11-15 22:14:46 +01:00
|
|
|
ItemPointerSet(&(tuple.t_self), blkno, offnum);
|
2007-09-20 19:56:33 +02:00
|
|
|
|
|
|
|
/*
|
|
|
|
* DEAD item pointers are to be vacuumed normally; but we don't
|
2007-11-15 22:14:46 +01:00
|
|
|
* count them in tups_vacuumed, else we'd be double-counting (at
|
|
|
|
* least in the common case where heap_page_prune() just freed up
|
|
|
|
* a non-HOT tuple).
|
2007-09-20 19:56:33 +02:00
|
|
|
*/
|
|
|
|
if (ItemIdIsDead(itemid))
|
|
|
|
{
|
|
|
|
lazy_record_dead_tuple(vacrelstats, &(tuple.t_self));
|
2008-12-03 14:05:22 +01:00
|
|
|
all_visible = false;
|
2007-09-20 19:56:33 +02:00
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
|
|
|
Assert(ItemIdIsNormal(itemid));
|
|
|
|
|
2001-07-14 00:55:59 +02:00
|
|
|
tuple.t_data = (HeapTupleHeader) PageGetItem(page, itemid);
|
|
|
|
tuple.t_len = ItemIdGetLength(itemid);
|
|
|
|
|
|
|
|
tupgone = false;
|
|
|
|
|
2004-10-16 00:40:29 +02:00
|
|
|
switch (HeapTupleSatisfiesVacuum(tuple.t_data, OldestXmin, buf))
|
2001-07-14 00:55:59 +02:00
|
|
|
{
|
|
|
|
case HEAPTUPLE_DEAD:
|
2007-11-15 22:14:46 +01:00
|
|
|
|
2007-09-20 19:56:33 +02:00
|
|
|
/*
|
|
|
|
* Ordinarily, DEAD tuples would have been removed by
|
|
|
|
* heap_page_prune(), but it's possible that the tuple
|
|
|
|
* state changed since heap_page_prune() looked. In
|
|
|
|
* particular an INSERT_IN_PROGRESS tuple could have
|
|
|
|
* changed to DEAD if the inserter aborted. So this
|
|
|
|
* cannot be considered an error condition.
|
|
|
|
*
|
|
|
|
* If the tuple is HOT-updated then it must only be
|
2007-11-15 22:14:46 +01:00
|
|
|
* removed by a prune operation; so we keep it just as if
|
|
|
|
* it were RECENTLY_DEAD. Also, if it's a heap-only
|
|
|
|
* tuple, we choose to keep it, because it'll be a lot
|
|
|
|
* cheaper to get rid of it in the next pruning pass than
|
|
|
|
* to treat it like an indexed tuple.
|
2007-09-20 19:56:33 +02:00
|
|
|
*/
|
|
|
|
if (HeapTupleIsHotUpdated(&tuple) ||
|
|
|
|
HeapTupleIsHeapOnly(&tuple))
|
|
|
|
nkeep += 1;
|
|
|
|
else
|
2007-11-15 22:14:46 +01:00
|
|
|
tupgone = true; /* we can delete the tuple */
|
2008-12-03 14:05:22 +01:00
|
|
|
all_visible = false;
|
2001-07-14 00:55:59 +02:00
|
|
|
break;
|
|
|
|
case HEAPTUPLE_LIVE:
|
Fix recently-understood problems with handling of XID freezing, particularly
in PITR scenarios. We now WAL-log the replacement of old XIDs with
FrozenTransactionId, so that such replacement is guaranteed to propagate to
PITR slave databases. Also, rather than relying on hint-bit updates to be
preserved, pg_clog is not truncated until all instances of an XID are known to
have been replaced by FrozenTransactionId. Add new GUC variables and
pg_autovacuum columns to allow management of the freezing policy, so that
users can trade off the size of pg_clog against the amount of freezing work
done. Revise the already-existing code that forces autovacuum of tables
approaching the wraparound point to make it more bulletproof; also, revise the
autovacuum logic so that anti-wraparound vacuuming is done per-table rather
than per-database. initdb forced because of changes in pg_class, pg_database,
and pg_autovacuum catalogs. Heikki Linnakangas, Simon Riggs, and Tom Lane.
2006-11-05 23:42:10 +01:00
|
|
|
/* Tuple is good --- but let's do some validity checks */
|
2004-02-12 06:39:55 +01:00
|
|
|
if (onerel->rd_rel->relhasoids &&
|
|
|
|
!OidIsValid(HeapTupleGetOid(&tuple)))
|
|
|
|
elog(WARNING, "relation \"%s\" TID %u/%u: OID is invalid",
|
|
|
|
relname, blkno, offnum);
|
2008-12-03 14:05:22 +01:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Is the tuple definitely visible to all transactions?
|
|
|
|
*
|
|
|
|
* NB: Like with per-tuple hint bits, we can't set the
|
|
|
|
* PD_ALL_VISIBLE flag if the inserter committed
|
|
|
|
* asynchronously. See SetHintBits for more info. Check
|
|
|
|
* that the HEAP_XMIN_COMMITTED hint bit is set because of
|
|
|
|
* that.
|
|
|
|
*/
|
|
|
|
if (all_visible)
|
|
|
|
{
|
|
|
|
TransactionId xmin;
|
|
|
|
|
|
|
|
if (!(tuple.t_data->t_infomask & HEAP_XMIN_COMMITTED))
|
|
|
|
{
|
|
|
|
all_visible = false;
|
|
|
|
break;
|
|
|
|
}
|
2009-06-11 16:49:15 +02:00
|
|
|
|
2008-12-03 14:05:22 +01:00
|
|
|
/*
|
2009-06-11 16:49:15 +02:00
|
|
|
* The inserter definitely committed. But is it old
|
|
|
|
* enough that everyone sees it as committed?
|
2008-12-03 14:05:22 +01:00
|
|
|
*/
|
|
|
|
xmin = HeapTupleHeaderGetXmin(tuple.t_data);
|
|
|
|
if (!TransactionIdPrecedes(xmin, OldestXmin))
|
|
|
|
{
|
|
|
|
all_visible = false;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
}
|
2001-07-14 00:55:59 +02:00
|
|
|
break;
|
|
|
|
case HEAPTUPLE_RECENTLY_DEAD:
|
2001-10-25 07:50:21 +02:00
|
|
|
|
2001-07-14 00:55:59 +02:00
|
|
|
/*
|
2005-10-15 04:49:52 +02:00
|
|
|
* If tuple is recently deleted then we must not remove it
|
|
|
|
* from relation.
|
2001-07-14 00:55:59 +02:00
|
|
|
*/
|
|
|
|
nkeep += 1;
|
2008-12-03 14:05:22 +01:00
|
|
|
all_visible = false;
|
2001-07-14 00:55:59 +02:00
|
|
|
break;
|
|
|
|
case HEAPTUPLE_INSERT_IN_PROGRESS:
|
|
|
|
/* This is an expected case during concurrent vacuum */
|
2008-12-03 14:05:22 +01:00
|
|
|
all_visible = false;
|
2001-07-14 00:55:59 +02:00
|
|
|
break;
|
|
|
|
case HEAPTUPLE_DELETE_IN_PROGRESS:
|
|
|
|
/* This is an expected case during concurrent vacuum */
|
2008-12-03 14:05:22 +01:00
|
|
|
all_visible = false;
|
2001-07-14 00:55:59 +02:00
|
|
|
break;
|
|
|
|
default:
|
2003-07-20 23:56:35 +02:00
|
|
|
elog(ERROR, "unexpected HeapTupleSatisfiesVacuum result");
|
2001-07-14 00:55:59 +02:00
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (tupgone)
|
|
|
|
{
|
|
|
|
lazy_record_dead_tuple(vacrelstats, &(tuple.t_self));
|
Allow read only connections during recovery, known as Hot Standby.
Enabled by recovery_connections = on (default) and forcing archive recovery using a recovery.conf. Recovery processing now emulates the original transactions as they are replayed, providing full locking and MVCC behaviour for read only queries. Recovery must enter consistent state before connections are allowed, so there is a delay, typically short, before connections succeed. Replay of recovering transactions can conflict and in some cases deadlock with queries during recovery; these result in query cancellation after max_standby_delay seconds have expired. Infrastructure changes have minor effects on normal running, though introduce four new types of WAL record.
New test mode "make standbycheck" allows regression tests of static command behaviour on a standby server while in recovery. Typical and extreme dynamic behaviours have been checked via code inspection and manual testing. Few port specific behaviours have been utilised, though primary testing has been on Linux only so far.
This commit is the basic patch. Additional changes will follow in this release to enhance some aspects of behaviour, notably improved handling of conflicts, deadlock detection and query cancellation. Changes to VACUUM FULL are also required.
Simon Riggs, with significant and lengthy review by Heikki Linnakangas, including streamlined redesign of snapshot creation and two-phase commit.
Important contributions from Florian Pflug, Mark Kirkwood, Merlin Moncure, Greg Stark, Gianni Ciolli, Gabriele Bartolini, Hannu Krosing, Robert Haas, Tatsuo Ishii, Hiroyuki Yamada plus support and feedback from many other community members.
2009-12-19 02:32:45 +01:00
|
|
|
HeapTupleHeaderAdvanceLatestRemovedXid(tuple.t_data,
|
2010-02-26 03:01:40 +01:00
|
|
|
&vacrelstats->latestRemovedXid);
|
2001-07-14 00:55:59 +02:00
|
|
|
tups_vacuumed += 1;
|
2011-03-08 19:13:52 +01:00
|
|
|
has_dead_tuples = true;
|
2001-07-14 00:55:59 +02:00
|
|
|
}
|
|
|
|
else
|
|
|
|
{
|
|
|
|
num_tuples += 1;
|
|
|
|
hastup = true;
|
2006-07-10 18:20:52 +02:00
|
|
|
|
2006-10-04 02:30:14 +02:00
|
|
|
/*
|
2007-11-15 22:14:46 +01:00
|
|
|
* Each non-removable tuple must be checked to see if it needs
|
|
|
|
* freezing. Note we already have exclusive buffer lock.
|
2006-07-10 18:20:52 +02:00
|
|
|
*/
|
Fix recently-understood problems with handling of XID freezing, particularly
in PITR scenarios. We now WAL-log the replacement of old XIDs with
FrozenTransactionId, so that such replacement is guaranteed to propagate to
PITR slave databases. Also, rather than relying on hint-bit updates to be
preserved, pg_clog is not truncated until all instances of an XID are known to
have been replaced by FrozenTransactionId. Add new GUC variables and
pg_autovacuum columns to allow management of the freezing policy, so that
users can trade off the size of pg_clog against the amount of freezing work
done. Revise the already-existing code that forces autovacuum of tables
approaching the wraparound point to make it more bulletproof; also, revise the
autovacuum logic so that anti-wraparound vacuuming is done per-table rather
than per-database. initdb forced because of changes in pg_class, pg_database,
and pg_autovacuum catalogs. Heikki Linnakangas, Simon Riggs, and Tom Lane.
2006-11-05 23:42:10 +01:00
|
|
|
if (heap_freeze_tuple(tuple.t_data, FreezeLimit,
|
2007-09-20 19:56:33 +02:00
|
|
|
InvalidBuffer))
|
Fix recently-understood problems with handling of XID freezing, particularly
in PITR scenarios. We now WAL-log the replacement of old XIDs with
FrozenTransactionId, so that such replacement is guaranteed to propagate to
PITR slave databases. Also, rather than relying on hint-bit updates to be
preserved, pg_clog is not truncated until all instances of an XID are known to
have been replaced by FrozenTransactionId. Add new GUC variables and
pg_autovacuum columns to allow management of the freezing policy, so that
users can trade off the size of pg_clog against the amount of freezing work
done. Revise the already-existing code that forces autovacuum of tables
approaching the wraparound point to make it more bulletproof; also, revise the
autovacuum logic so that anti-wraparound vacuuming is done per-table rather
than per-database. initdb forced because of changes in pg_class, pg_database,
and pg_autovacuum catalogs. Heikki Linnakangas, Simon Riggs, and Tom Lane.
2006-11-05 23:42:10 +01:00
|
|
|
frozen[nfrozen++] = offnum;
|
2001-07-14 00:55:59 +02:00
|
|
|
}
|
2001-10-25 07:50:21 +02:00
|
|
|
} /* scan along page */
|
2001-07-14 00:55:59 +02:00
|
|
|
|
Fix recently-understood problems with handling of XID freezing, particularly
in PITR scenarios. We now WAL-log the replacement of old XIDs with
FrozenTransactionId, so that such replacement is guaranteed to propagate to
PITR slave databases. Also, rather than relying on hint-bit updates to be
preserved, pg_clog is not truncated until all instances of an XID are known to
have been replaced by FrozenTransactionId. Add new GUC variables and
pg_autovacuum columns to allow management of the freezing policy, so that
users can trade off the size of pg_clog against the amount of freezing work
done. Revise the already-existing code that forces autovacuum of tables
approaching the wraparound point to make it more bulletproof; also, revise the
autovacuum logic so that anti-wraparound vacuuming is done per-table rather
than per-database. initdb forced because of changes in pg_class, pg_database,
and pg_autovacuum catalogs. Heikki Linnakangas, Simon Riggs, and Tom Lane.
2006-11-05 23:42:10 +01:00
|
|
|
/*
|
|
|
|
* If we froze any tuples, mark the buffer dirty, and write a WAL
|
|
|
|
* record recording the changes. We must log the changes to be
|
|
|
|
* crash-safe against future truncation of CLOG.
|
|
|
|
*/
|
|
|
|
if (nfrozen > 0)
|
|
|
|
{
|
|
|
|
MarkBufferDirty(buf);
|
2010-12-13 18:34:26 +01:00
|
|
|
if (RelationNeedsWAL(onerel))
|
Fix recently-understood problems with handling of XID freezing, particularly
in PITR scenarios. We now WAL-log the replacement of old XIDs with
FrozenTransactionId, so that such replacement is guaranteed to propagate to
PITR slave databases. Also, rather than relying on hint-bit updates to be
preserved, pg_clog is not truncated until all instances of an XID are known to
have been replaced by FrozenTransactionId. Add new GUC variables and
pg_autovacuum columns to allow management of the freezing policy, so that
users can trade off the size of pg_clog against the amount of freezing work
done. Revise the already-existing code that forces autovacuum of tables
approaching the wraparound point to make it more bulletproof; also, revise the
autovacuum logic so that anti-wraparound vacuuming is done per-table rather
than per-database. initdb forced because of changes in pg_class, pg_database,
and pg_autovacuum catalogs. Heikki Linnakangas, Simon Riggs, and Tom Lane.
2006-11-05 23:42:10 +01:00
|
|
|
{
|
|
|
|
XLogRecPtr recptr;
|
|
|
|
|
|
|
|
recptr = log_heap_freeze(onerel, buf, FreezeLimit,
|
|
|
|
frozen, nfrozen);
|
|
|
|
PageSetLSN(page, recptr);
|
|
|
|
PageSetTLI(page, ThisTimeLineID);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2006-09-13 19:47:08 +02:00
|
|
|
/*
|
|
|
|
* If there are no indexes then we can vacuum the page right now
|
|
|
|
* instead of doing a second scan.
|
|
|
|
*/
|
|
|
|
if (nindexes == 0 &&
|
|
|
|
vacrelstats->num_dead_tuples > 0)
|
|
|
|
{
|
|
|
|
/* Remove tuples from heap */
|
|
|
|
lazy_vacuum_page(onerel, blkno, buf, 0, vacrelstats);
|
2010-07-06 21:19:02 +02:00
|
|
|
|
2010-04-21 19:20:56 +02:00
|
|
|
/*
|
|
|
|
* Forget the now-vacuumed tuples, and press on, but be careful
|
2010-07-06 21:19:02 +02:00
|
|
|
* not to reset latestRemovedXid since we want that value to be
|
|
|
|
* valid.
|
2010-04-21 19:20:56 +02:00
|
|
|
*/
|
2006-09-13 19:47:08 +02:00
|
|
|
vacrelstats->num_dead_tuples = 0;
|
|
|
|
vacuumed_pages++;
|
|
|
|
}
|
|
|
|
|
2008-09-30 12:52:14 +02:00
|
|
|
freespace = PageGetHeapFreeSpace(page);
|
|
|
|
|
2008-12-03 14:05:22 +01:00
|
|
|
/* Update the all-visible flag on the page */
|
|
|
|
if (!PageIsAllVisible(page) && all_visible)
|
|
|
|
{
|
|
|
|
PageSetAllVisible(page);
|
2009-08-24 04:18:32 +02:00
|
|
|
SetBufferCommitInfoNeedsSave(buf);
|
2008-12-03 14:05:22 +01:00
|
|
|
}
|
2011-04-10 17:42:00 +02:00
|
|
|
|
2011-03-08 19:13:52 +01:00
|
|
|
/*
|
|
|
|
* It's possible for the value returned by GetOldestXmin() to move
|
|
|
|
* backwards, so it's not wrong for us to see tuples that appear to
|
|
|
|
* not be visible to everyone yet, while PD_ALL_VISIBLE is already
|
|
|
|
* set. The real safe xmin value never moves backwards, but
|
|
|
|
* GetOldestXmin() is conservative and sometimes returns a value
|
2011-04-10 17:42:00 +02:00
|
|
|
* that's unnecessarily small, so if we see that contradiction it just
|
|
|
|
* means that the tuples that we think are not visible to everyone yet
|
|
|
|
* actually are, and the PD_ALL_VISIBLE flag is correct.
|
2011-03-08 19:13:52 +01:00
|
|
|
*
|
|
|
|
* There should never be dead tuples on a page with PD_ALL_VISIBLE
|
|
|
|
* set, however.
|
|
|
|
*/
|
|
|
|
else if (PageIsAllVisible(page) && has_dead_tuples)
|
2008-12-03 14:05:22 +01:00
|
|
|
{
|
2011-03-08 19:13:52 +01:00
|
|
|
elog(WARNING, "page containing dead tuples is marked as all-visible in relation \"%s\" page %u",
|
2009-08-24 04:18:32 +02:00
|
|
|
relname, blkno);
|
2008-12-03 14:05:22 +01:00
|
|
|
PageClearAllVisible(page);
|
2009-08-24 04:18:32 +02:00
|
|
|
SetBufferCommitInfoNeedsSave(buf);
|
2008-12-03 14:05:22 +01:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Normally, we would drop the lock on the heap page before
|
2009-08-24 04:18:32 +02:00
|
|
|
* updating the visibility map, but since this case shouldn't
|
|
|
|
* happen anyway, don't worry about that.
|
2008-12-03 14:05:22 +01:00
|
|
|
*/
|
Make the visibility map crash-safe.
This involves two main changes from the previous behavior. First,
when we set a bit in the visibility map, emit a new WAL record of type
XLOG_HEAP2_VISIBLE. Replay sets the page-level PD_ALL_VISIBLE bit and
the visibility map bit. Second, when inserting, updating, or deleting
a tuple, we can no longer get away with clearing the visibility map
bit after releasing the lock on the corresponding heap page, because
an intervening crash might leave the visibility map bit set and the
page-level bit clear. Making this work requires a bit of interface
refactoring.
In passing, a few minor but related cleanups: change the test in
visibilitymap_set and visibilitymap_clear to throw an error if the
wrong page (or no page) is pinned, rather than silently doing nothing;
this case should never occur. Also, remove duplicate definitions of
InvalidXLogRecPtr.
Patch by me, review by Noah Misch.
2011-06-22 05:04:40 +02:00
|
|
|
visibilitymap_pin(onerel, blkno, &vmbuffer);
|
|
|
|
visibilitymap_clear(onerel, blkno, vmbuffer);
|
2008-12-03 14:05:22 +01:00
|
|
|
}
|
|
|
|
|
|
|
|
LockBuffer(buf, BUFFER_LOCK_UNLOCK);
|
|
|
|
|
|
|
|
/* Update the visibility map */
|
|
|
|
if (!all_visible_according_to_vm && all_visible)
|
|
|
|
{
|
|
|
|
visibilitymap_pin(onerel, blkno, &vmbuffer);
|
|
|
|
LockBuffer(buf, BUFFER_LOCK_SHARE);
|
|
|
|
if (PageIsAllVisible(page))
|
Make the visibility map crash-safe.
This involves two main changes from the previous behavior. First,
when we set a bit in the visibility map, emit a new WAL record of type
XLOG_HEAP2_VISIBLE. Replay sets the page-level PD_ALL_VISIBLE bit and
the visibility map bit. Second, when inserting, updating, or deleting
a tuple, we can no longer get away with clearing the visibility map
bit after releasing the lock on the corresponding heap page, because
an intervening crash might leave the visibility map bit set and the
page-level bit clear. Making this work requires a bit of interface
refactoring.
In passing, a few minor but related cleanups: change the test in
visibilitymap_set and visibilitymap_clear to throw an error if the
wrong page (or no page) is pinned, rather than silently doing nothing;
this case should never occur. Also, remove duplicate definitions of
InvalidXLogRecPtr.
Patch by me, review by Noah Misch.
2011-06-22 05:04:40 +02:00
|
|
|
visibilitymap_set(onerel, blkno, InvalidXLogRecPtr, vmbuffer);
|
2008-12-03 14:05:22 +01:00
|
|
|
LockBuffer(buf, BUFFER_LOCK_UNLOCK);
|
|
|
|
}
|
|
|
|
|
|
|
|
ReleaseBuffer(buf);
|
|
|
|
|
2008-09-30 12:52:14 +02:00
|
|
|
/* Remember the location of the last page with nonremovable tuples */
|
|
|
|
if (hastup)
|
|
|
|
vacrelstats->nonempty_pages = blkno + 1;
|
|
|
|
|
2001-07-14 00:55:59 +02:00
|
|
|
/*
|
2001-10-25 07:50:21 +02:00
|
|
|
* If we remembered any tuples for deletion, then the page will be
|
2005-10-15 04:49:52 +02:00
|
|
|
* visited again by lazy_vacuum_heap, which will compute and record
|
|
|
|
* its post-compaction free space. If not, then we're done with this
|
2006-10-04 02:30:14 +02:00
|
|
|
* page, so remember its free space as-is. (This path will always be
|
|
|
|
* taken if there are no indexes.)
|
2001-07-14 00:55:59 +02:00
|
|
|
*/
|
|
|
|
if (vacrelstats->num_dead_tuples == prev_dead_count)
|
2008-09-30 12:52:14 +02:00
|
|
|
RecordPageWithFreeSpace(onerel, blkno, freespace);
|
2001-07-14 00:55:59 +02:00
|
|
|
}
|
|
|
|
|
2001-07-18 02:46:25 +02:00
|
|
|
/* save stats for use later */
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
vacrelstats->scanned_tuples = num_tuples;
|
2004-12-01 20:00:56 +01:00
|
|
|
vacrelstats->tuples_deleted = tups_vacuumed;
|
2001-07-18 02:46:25 +02:00
|
|
|
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
/* now we can compute the new value for pg_class.reltuples */
|
|
|
|
vacrelstats->new_rel_tuples = vac_estimate_reltuples(onerel, false,
|
|
|
|
nblocks,
|
2011-06-09 20:32:50 +02:00
|
|
|
vacrelstats->scanned_pages,
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
num_tuples);
|
|
|
|
|
2001-07-14 00:55:59 +02:00
|
|
|
/* If any tuples need to be deleted, perform final vacuum cycle */
|
2003-02-22 01:45:05 +01:00
|
|
|
/* XXX put a threshold on min number of tuples here? */
|
2001-07-14 00:55:59 +02:00
|
|
|
if (vacrelstats->num_dead_tuples > 0)
|
|
|
|
{
|
Allow read only connections during recovery, known as Hot Standby.
Enabled by recovery_connections = on (default) and forcing archive recovery using a recovery.conf. Recovery processing now emulates the original transactions as they are replayed, providing full locking and MVCC behaviour for read only queries. Recovery must enter consistent state before connections are allowed, so there is a delay, typically short, before connections succeed. Replay of recovering transactions can conflict and in some cases deadlock with queries during recovery; these result in query cancellation after max_standby_delay seconds have expired. Infrastructure changes have minor effects on normal running, though introduce four new types of WAL record.
New test mode "make standbycheck" allows regression tests of static command behaviour on a standby server while in recovery. Typical and extreme dynamic behaviours have been checked via code inspection and manual testing. Few port specific behaviours have been utilised, though primary testing has been on Linux only so far.
This commit is the basic patch. Additional changes will follow in this release to enhance some aspects of behaviour, notably improved handling of conflicts, deadlock detection and query cancellation. Changes to VACUUM FULL are also required.
Simon Riggs, with significant and lengthy review by Heikki Linnakangas, including streamlined redesign of snapshot creation and two-phase commit.
Important contributions from Florian Pflug, Mark Kirkwood, Merlin Moncure, Greg Stark, Gianni Ciolli, Gabriele Bartolini, Hannu Krosing, Robert Haas, Tatsuo Ishii, Hiroyuki Yamada plus support and feedback from many other community members.
2009-12-19 02:32:45 +01:00
|
|
|
/* Log cleanup info before we touch indexes */
|
|
|
|
vacuum_log_cleanup_info(onerel, vacrelstats);
|
|
|
|
|
2001-07-14 00:55:59 +02:00
|
|
|
/* Remove index entries */
|
|
|
|
for (i = 0; i < nindexes; i++)
|
2004-12-01 20:00:56 +01:00
|
|
|
lazy_vacuum_index(Irel[i],
|
2006-05-03 00:25:10 +02:00
|
|
|
&indstats[i],
|
2004-12-01 20:00:56 +01:00
|
|
|
vacrelstats);
|
2001-07-14 00:55:59 +02:00
|
|
|
/* Remove tuples from heap */
|
|
|
|
lazy_vacuum_heap(onerel, vacrelstats);
|
2007-04-18 18:44:18 +02:00
|
|
|
vacrelstats->num_index_scans++;
|
2001-07-14 00:55:59 +02:00
|
|
|
}
|
2006-05-03 00:25:10 +02:00
|
|
|
|
2008-12-03 14:05:22 +01:00
|
|
|
/* Release the pin on the visibility map page */
|
|
|
|
if (BufferIsValid(vmbuffer))
|
|
|
|
{
|
|
|
|
ReleaseBuffer(vmbuffer);
|
|
|
|
vmbuffer = InvalidBuffer;
|
|
|
|
}
|
|
|
|
|
2006-05-03 00:25:10 +02:00
|
|
|
/* Do post-vacuum cleanup and statistics update for each index */
|
|
|
|
for (i = 0; i < nindexes; i++)
|
|
|
|
lazy_cleanup_index(Irel[i], indstats[i], vacrelstats);
|
2001-07-14 00:55:59 +02:00
|
|
|
|
2006-09-13 19:47:08 +02:00
|
|
|
/* If no indexes, make log report that lazy_vacuum_heap would've made */
|
|
|
|
if (vacuumed_pages)
|
|
|
|
ereport(elevel,
|
|
|
|
(errmsg("\"%s\": removed %.0f row versions in %u pages",
|
|
|
|
RelationGetRelationName(onerel),
|
|
|
|
tups_vacuumed, vacuumed_pages)));
|
|
|
|
|
2003-07-20 23:56:35 +02:00
|
|
|
ereport(elevel,
|
2008-12-03 14:05:22 +01:00
|
|
|
(errmsg("\"%s\": found %.0f removable, %.0f nonremovable row versions in %u out of %u pages",
|
2003-07-20 23:56:35 +02:00
|
|
|
RelationGetRelationName(onerel),
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
tups_vacuumed, num_tuples,
|
|
|
|
vacrelstats->scanned_pages, nblocks),
|
2003-09-25 08:58:07 +02:00
|
|
|
errdetail("%.0f dead row versions cannot be removed yet.\n"
|
2003-07-20 23:56:35 +02:00
|
|
|
"There were %.0f unused item pointers.\n"
|
|
|
|
"%u pages are entirely empty.\n"
|
2005-10-04 00:52:26 +02:00
|
|
|
"%s.",
|
2003-07-20 23:56:35 +02:00
|
|
|
nkeep,
|
|
|
|
nunused,
|
|
|
|
empty_pages,
|
2005-10-04 00:52:26 +02:00
|
|
|
pg_rusage_show(&ru0))));
|
2001-07-14 00:55:59 +02:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
* lazy_vacuum_heap() -- second pass over the heap
|
|
|
|
*
|
|
|
|
* This routine marks dead tuples as unused and compacts out free
|
|
|
|
* space on their pages. Pages not having dead tuples recorded from
|
|
|
|
* lazy_scan_heap are not visited at all.
|
|
|
|
*
|
|
|
|
* Note: the reason for doing this as a second pass is we cannot remove
|
|
|
|
* the tuples until we've removed their index entries, and we want to
|
|
|
|
* process index entry removal in batches as large as possible.
|
|
|
|
*/
|
|
|
|
static void
|
|
|
|
lazy_vacuum_heap(Relation onerel, LVRelStats *vacrelstats)
|
|
|
|
{
|
|
|
|
int tupindex;
|
|
|
|
int npages;
|
2005-10-04 00:52:26 +02:00
|
|
|
PGRUsage ru0;
|
2001-07-14 00:55:59 +02:00
|
|
|
|
2005-10-04 00:52:26 +02:00
|
|
|
pg_rusage_init(&ru0);
|
2001-07-14 00:55:59 +02:00
|
|
|
npages = 0;
|
|
|
|
|
|
|
|
tupindex = 0;
|
|
|
|
while (tupindex < vacrelstats->num_dead_tuples)
|
|
|
|
{
|
2001-10-25 07:50:21 +02:00
|
|
|
BlockNumber tblk;
|
2001-07-14 00:55:59 +02:00
|
|
|
Buffer buf;
|
|
|
|
Page page;
|
2008-09-30 12:52:14 +02:00
|
|
|
Size freespace;
|
2001-07-14 00:55:59 +02:00
|
|
|
|
2004-02-10 04:42:45 +01:00
|
|
|
vacuum_delay_point();
|
2004-02-06 20:36:18 +01:00
|
|
|
|
2001-07-14 00:55:59 +02:00
|
|
|
tblk = ItemPointerGetBlockNumber(&vacrelstats->dead_tuples[tupindex]);
|
Unite ReadBufferWithFork, ReadBufferWithStrategy, and ZeroOrReadBuffer
functions into one ReadBufferExtended function, that takes the strategy
and mode as argument. There's three modes, RBM_NORMAL which is the default
used by plain ReadBuffer(), RBM_ZERO, which replaces ZeroOrReadBuffer, and
a new mode RBM_ZERO_ON_ERROR, which allows callers to read corrupt pages
without throwing an error. The FSM needs the new mode to recover from
corrupt pages, which could happend if we crash after extending an FSM file,
and the new page is "torn".
Add fork number to some error messages in bufmgr.c, that still lacked it.
2008-10-31 16:05:00 +01:00
|
|
|
buf = ReadBufferExtended(onerel, MAIN_FORKNUM, tblk, RBM_NORMAL,
|
|
|
|
vac_strategy);
|
2001-07-14 00:55:59 +02:00
|
|
|
LockBufferForCleanup(buf);
|
|
|
|
tupindex = lazy_vacuum_page(onerel, tblk, buf, tupindex, vacrelstats);
|
2008-09-30 12:52:14 +02:00
|
|
|
|
2001-07-14 00:55:59 +02:00
|
|
|
/* Now that we've compacted the page, record its available space */
|
|
|
|
page = BufferGetPage(buf);
|
2008-09-30 12:52:14 +02:00
|
|
|
freespace = PageGetHeapFreeSpace(page);
|
|
|
|
|
2006-04-01 01:32:07 +02:00
|
|
|
UnlockReleaseBuffer(buf);
|
2008-09-30 12:52:14 +02:00
|
|
|
RecordPageWithFreeSpace(onerel, tblk, freespace);
|
2001-07-14 00:55:59 +02:00
|
|
|
npages++;
|
|
|
|
}
|
|
|
|
|
2003-07-20 23:56:35 +02:00
|
|
|
ereport(elevel,
|
2003-09-25 08:58:07 +02:00
|
|
|
(errmsg("\"%s\": removed %d row versions in %d pages",
|
2003-07-20 23:56:35 +02:00
|
|
|
RelationGetRelationName(onerel),
|
|
|
|
tupindex, npages),
|
2005-10-04 00:52:26 +02:00
|
|
|
errdetail("%s.",
|
|
|
|
pg_rusage_show(&ru0))));
|
2001-07-14 00:55:59 +02:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* lazy_vacuum_page() -- free dead tuples on a page
|
|
|
|
* and repair its fragmentation.
|
|
|
|
*
|
2007-09-20 19:56:33 +02:00
|
|
|
* Caller must hold pin and buffer cleanup lock on the buffer.
|
2001-07-14 00:55:59 +02:00
|
|
|
*
|
|
|
|
* tupindex is the index in vacrelstats->dead_tuples of the first dead
|
|
|
|
* tuple for this page. We assume the rest follow sequentially.
|
|
|
|
* The return value is the first tupindex after the tuples of this page.
|
|
|
|
*/
|
|
|
|
static int
|
|
|
|
lazy_vacuum_page(Relation onerel, BlockNumber blkno, Buffer buffer,
|
|
|
|
int tupindex, LVRelStats *vacrelstats)
|
|
|
|
{
|
|
|
|
Page page = BufferGetPage(buffer);
|
2007-09-20 19:56:33 +02:00
|
|
|
OffsetNumber unused[MaxOffsetNumber];
|
|
|
|
int uncnt = 0;
|
2001-07-14 00:55:59 +02:00
|
|
|
|
|
|
|
START_CRIT_SECTION();
|
2006-04-01 01:32:07 +02:00
|
|
|
|
2001-07-14 00:55:59 +02:00
|
|
|
for (; tupindex < vacrelstats->num_dead_tuples; tupindex++)
|
|
|
|
{
|
2001-10-25 07:50:21 +02:00
|
|
|
BlockNumber tblk;
|
|
|
|
OffsetNumber toff;
|
2007-09-20 19:56:33 +02:00
|
|
|
ItemId itemid;
|
2001-07-14 00:55:59 +02:00
|
|
|
|
|
|
|
tblk = ItemPointerGetBlockNumber(&vacrelstats->dead_tuples[tupindex]);
|
|
|
|
if (tblk != blkno)
|
|
|
|
break; /* past end of tuples for this block */
|
|
|
|
toff = ItemPointerGetOffsetNumber(&vacrelstats->dead_tuples[tupindex]);
|
|
|
|
itemid = PageGetItemId(page, toff);
|
2007-09-13 00:10:26 +02:00
|
|
|
ItemIdSetUnused(itemid);
|
2007-09-20 19:56:33 +02:00
|
|
|
unused[uncnt++] = toff;
|
2001-07-14 00:55:59 +02:00
|
|
|
}
|
|
|
|
|
2007-09-20 19:56:33 +02:00
|
|
|
PageRepairFragmentation(page);
|
2001-07-14 00:55:59 +02:00
|
|
|
|
2006-04-01 01:32:07 +02:00
|
|
|
MarkBufferDirty(buffer);
|
|
|
|
|
2002-08-06 04:36:35 +02:00
|
|
|
/* XLOG stuff */
|
2010-12-13 18:34:26 +01:00
|
|
|
if (RelationNeedsWAL(onerel))
|
2001-07-14 00:55:59 +02:00
|
|
|
{
|
|
|
|
XLogRecPtr recptr;
|
|
|
|
|
2007-09-20 19:56:33 +02:00
|
|
|
recptr = log_heap_clean(onerel, buffer,
|
|
|
|
NULL, 0, NULL, 0,
|
|
|
|
unused, uncnt,
|
2010-02-08 05:33:55 +01:00
|
|
|
vacrelstats->latestRemovedXid);
|
2001-07-14 00:55:59 +02:00
|
|
|
PageSetLSN(page, recptr);
|
2004-07-22 00:31:26 +02:00
|
|
|
PageSetTLI(page, ThisTimeLineID);
|
2001-07-14 00:55:59 +02:00
|
|
|
}
|
2002-08-06 04:36:35 +02:00
|
|
|
|
2001-07-14 00:55:59 +02:00
|
|
|
END_CRIT_SECTION();
|
|
|
|
|
|
|
|
return tupindex;
|
|
|
|
}
|
|
|
|
|
2001-07-18 02:46:25 +02:00
|
|
|
/*
|
2006-05-03 00:25:10 +02:00
|
|
|
* lazy_vacuum_index() -- vacuum one index relation.
|
2001-07-18 02:46:25 +02:00
|
|
|
*
|
2006-05-03 00:25:10 +02:00
|
|
|
* Delete all the index entries pointing to tuples listed in
|
|
|
|
* vacrelstats->dead_tuples, and update running statistics.
|
2001-07-18 02:46:25 +02:00
|
|
|
*/
|
|
|
|
static void
|
2006-05-03 00:25:10 +02:00
|
|
|
lazy_vacuum_index(Relation indrel,
|
|
|
|
IndexBulkDeleteResult **stats,
|
|
|
|
LVRelStats *vacrelstats)
|
2001-07-18 02:46:25 +02:00
|
|
|
{
|
2006-05-03 00:25:10 +02:00
|
|
|
IndexVacuumInfo ivinfo;
|
2005-10-04 00:52:26 +02:00
|
|
|
PGRUsage ru0;
|
2001-07-18 02:46:25 +02:00
|
|
|
|
2005-10-04 00:52:26 +02:00
|
|
|
pg_rusage_init(&ru0);
|
2001-07-18 02:46:25 +02:00
|
|
|
|
2006-05-03 00:25:10 +02:00
|
|
|
ivinfo.index = indrel;
|
2009-03-24 21:17:18 +01:00
|
|
|
ivinfo.analyze_only = false;
|
2009-06-07 00:13:52 +02:00
|
|
|
ivinfo.estimated_count = true;
|
2006-05-03 00:25:10 +02:00
|
|
|
ivinfo.message_level = elevel;
|
2009-06-07 00:13:52 +02:00
|
|
|
ivinfo.num_heap_tuples = vacrelstats->old_rel_tuples;
|
2007-05-30 22:12:03 +02:00
|
|
|
ivinfo.strategy = vac_strategy;
|
2003-02-22 01:45:05 +01:00
|
|
|
|
2006-05-03 00:25:10 +02:00
|
|
|
/* Do bulk deletion */
|
|
|
|
*stats = index_bulk_delete(&ivinfo, *stats,
|
|
|
|
lazy_tid_reaped, (void *) vacrelstats);
|
2003-02-22 01:45:05 +01:00
|
|
|
|
2003-07-20 23:56:35 +02:00
|
|
|
ereport(elevel,
|
2006-05-03 00:25:10 +02:00
|
|
|
(errmsg("scanned index \"%s\" to remove %d row versions",
|
2005-10-15 04:49:52 +02:00
|
|
|
RelationGetRelationName(indrel),
|
2006-05-03 00:25:10 +02:00
|
|
|
vacrelstats->num_dead_tuples),
|
|
|
|
errdetail("%s.", pg_rusage_show(&ru0))));
|
2001-07-18 02:46:25 +02:00
|
|
|
}
|
|
|
|
|
2001-07-14 00:55:59 +02:00
|
|
|
/*
|
2006-05-03 00:25:10 +02:00
|
|
|
* lazy_cleanup_index() -- do post-vacuum cleanup for one index relation.
|
2001-07-14 00:55:59 +02:00
|
|
|
*/
|
|
|
|
static void
|
2006-05-03 00:25:10 +02:00
|
|
|
lazy_cleanup_index(Relation indrel,
|
|
|
|
IndexBulkDeleteResult *stats,
|
|
|
|
LVRelStats *vacrelstats)
|
2001-07-14 00:55:59 +02:00
|
|
|
{
|
2006-05-03 00:25:10 +02:00
|
|
|
IndexVacuumInfo ivinfo;
|
2005-10-04 00:52:26 +02:00
|
|
|
PGRUsage ru0;
|
2001-07-14 00:55:59 +02:00
|
|
|
|
2005-10-04 00:52:26 +02:00
|
|
|
pg_rusage_init(&ru0);
|
2001-07-14 00:55:59 +02:00
|
|
|
|
2006-05-03 00:25:10 +02:00
|
|
|
ivinfo.index = indrel;
|
2009-03-24 21:17:18 +01:00
|
|
|
ivinfo.analyze_only = false;
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
ivinfo.estimated_count = (vacrelstats->scanned_pages < vacrelstats->rel_pages);
|
2006-05-03 00:25:10 +02:00
|
|
|
ivinfo.message_level = elevel;
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
ivinfo.num_heap_tuples = vacrelstats->new_rel_tuples;
|
2007-05-30 22:12:03 +02:00
|
|
|
ivinfo.strategy = vac_strategy;
|
2003-02-22 01:45:05 +01:00
|
|
|
|
2006-05-03 00:25:10 +02:00
|
|
|
stats = index_vacuum_cleanup(&ivinfo, stats);
|
2003-02-22 01:45:05 +01:00
|
|
|
|
|
|
|
if (!stats)
|
|
|
|
return;
|
|
|
|
|
2009-06-07 00:13:52 +02:00
|
|
|
/*
|
2009-06-11 16:49:15 +02:00
|
|
|
* Now update statistics in pg_class, but only if the index says the count
|
|
|
|
* is accurate.
|
2009-06-07 00:13:52 +02:00
|
|
|
*/
|
|
|
|
if (!stats->estimated_count)
|
|
|
|
vac_update_relstats(indrel,
|
|
|
|
stats->num_pages, stats->num_index_tuples,
|
|
|
|
false, InvalidTransactionId);
|
Restructure index AM interface for index building and index tuple deletion,
per previous discussion on pghackers. Most of the duplicate code in
different AMs' ambuild routines has been moved out to a common routine
in index.c; this means that all index types now do the right things about
inserting recently-dead tuples, etc. (I also removed support for EXTEND
INDEX in the ambuild routines, since that's about to go away anyway, and
it cluttered the code a lot.) The retail indextuple deletion routines have
been replaced by a "bulk delete" routine in which the indexscan is inside
the access method. I haven't pushed this change as far as it should go yet,
but it should allow considerable simplification of the internal bookkeeping
for deletions. Also, add flag columns to pg_am to eliminate various
hardcoded tests on AM OIDs, and remove unused pg_am columns.
Fix rtree and gist index types to not attempt to store NULLs; before this,
gist usually crashed, while rtree managed not to crash but computed wacko
bounding boxes for NULL entries (which might have had something to do with
the performance problems we've heard about occasionally).
Add AtEOXact routines to hash, rtree, and gist, all of which have static
state that needs to be reset after an error. We discovered this need long
ago for btree, but missed the other guys.
Oh, one more thing: concurrent VACUUM is now the default.
2001-07-16 00:48:19 +02:00
|
|
|
|
2003-07-20 23:56:35 +02:00
|
|
|
ereport(elevel,
|
2005-10-15 04:49:52 +02:00
|
|
|
(errmsg("index \"%s\" now contains %.0f row versions in %u pages",
|
|
|
|
RelationGetRelationName(indrel),
|
|
|
|
stats->num_index_tuples,
|
|
|
|
stats->num_pages),
|
|
|
|
errdetail("%.0f index row versions were removed.\n"
|
|
|
|
"%u index pages have been deleted, %u are currently reusable.\n"
|
|
|
|
"%s.",
|
|
|
|
stats->tuples_removed,
|
|
|
|
stats->pages_deleted, stats->pages_free,
|
|
|
|
pg_rusage_show(&ru0))));
|
Restructure index AM interface for index building and index tuple deletion,
per previous discussion on pghackers. Most of the duplicate code in
different AMs' ambuild routines has been moved out to a common routine
in index.c; this means that all index types now do the right things about
inserting recently-dead tuples, etc. (I also removed support for EXTEND
INDEX in the ambuild routines, since that's about to go away anyway, and
it cluttered the code a lot.) The retail indextuple deletion routines have
been replaced by a "bulk delete" routine in which the indexscan is inside
the access method. I haven't pushed this change as far as it should go yet,
but it should allow considerable simplification of the internal bookkeeping
for deletions. Also, add flag columns to pg_am to eliminate various
hardcoded tests on AM OIDs, and remove unused pg_am columns.
Fix rtree and gist index types to not attempt to store NULLs; before this,
gist usually crashed, while rtree managed not to crash but computed wacko
bounding boxes for NULL entries (which might have had something to do with
the performance problems we've heard about occasionally).
Add AtEOXact routines to hash, rtree, and gist, all of which have static
state that needs to be reset after an error. We discovered this need long
ago for btree, but missed the other guys.
Oh, one more thing: concurrent VACUUM is now the default.
2001-07-16 00:48:19 +02:00
|
|
|
|
2003-02-22 01:45:05 +01:00
|
|
|
pfree(stats);
|
2001-07-14 00:55:59 +02:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* lazy_truncate_heap - try to truncate off any empty pages at the end
|
|
|
|
*/
|
2010-02-09 22:43:30 +01:00
|
|
|
static void
|
Fix recently-understood problems with handling of XID freezing, particularly
in PITR scenarios. We now WAL-log the replacement of old XIDs with
FrozenTransactionId, so that such replacement is guaranteed to propagate to
PITR slave databases. Also, rather than relying on hint-bit updates to be
preserved, pg_clog is not truncated until all instances of an XID are known to
have been replaced by FrozenTransactionId. Add new GUC variables and
pg_autovacuum columns to allow management of the freezing policy, so that
users can trade off the size of pg_clog against the amount of freezing work
done. Revise the already-existing code that forces autovacuum of tables
approaching the wraparound point to make it more bulletproof; also, revise the
autovacuum logic so that anti-wraparound vacuuming is done per-table rather
than per-database. initdb forced because of changes in pg_class, pg_database,
and pg_autovacuum catalogs. Heikki Linnakangas, Simon Riggs, and Tom Lane.
2006-11-05 23:42:10 +01:00
|
|
|
lazy_truncate_heap(Relation onerel, LVRelStats *vacrelstats)
|
2001-07-14 00:55:59 +02:00
|
|
|
{
|
2001-10-25 07:50:21 +02:00
|
|
|
BlockNumber old_rel_pages = vacrelstats->rel_pages;
|
|
|
|
BlockNumber new_rel_pages;
|
2005-10-04 00:52:26 +02:00
|
|
|
PGRUsage ru0;
|
2001-07-14 00:55:59 +02:00
|
|
|
|
2005-10-04 00:52:26 +02:00
|
|
|
pg_rusage_init(&ru0);
|
2001-07-14 00:55:59 +02:00
|
|
|
|
|
|
|
/*
|
2005-10-15 04:49:52 +02:00
|
|
|
* We need full exclusive lock on the relation in order to do truncation.
|
|
|
|
* If we can't get it, give up rather than waiting --- we don't want to
|
|
|
|
* block other backends, and we don't want to deadlock (which is quite
|
|
|
|
* possible considering we already hold a lower-grade lock).
|
2001-07-14 00:55:59 +02:00
|
|
|
*/
|
2001-10-25 07:50:21 +02:00
|
|
|
if (!ConditionalLockRelation(onerel, AccessExclusiveLock))
|
2010-02-09 22:43:30 +01:00
|
|
|
return;
|
2001-07-14 00:55:59 +02:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Now that we have exclusive lock, look to see if the rel has grown
|
2005-10-15 04:49:52 +02:00
|
|
|
* whilst we were vacuuming with non-exclusive lock. If so, give up; the
|
|
|
|
* newly added pages presumably contain non-deletable tuples.
|
2001-07-14 00:55:59 +02:00
|
|
|
*/
|
|
|
|
new_rel_pages = RelationGetNumberOfBlocks(onerel);
|
|
|
|
if (new_rel_pages != old_rel_pages)
|
|
|
|
{
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
/*
|
2011-06-09 20:32:50 +02:00
|
|
|
* Note: we intentionally don't update vacrelstats->rel_pages with the
|
|
|
|
* new rel size here. If we did, it would amount to assuming that the
|
|
|
|
* new pages are empty, which is unlikely. Leaving the numbers alone
|
|
|
|
* amounts to assuming that the new pages have the same tuple density
|
|
|
|
* as existing ones, which is less unlikely.
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
*/
|
2001-07-14 00:55:59 +02:00
|
|
|
UnlockRelation(onerel, AccessExclusiveLock);
|
2010-02-09 22:43:30 +01:00
|
|
|
return;
|
2001-07-14 00:55:59 +02:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Scan backwards from the end to verify that the end pages actually
|
2007-09-16 04:37:46 +02:00
|
|
|
* contain no tuples. This is *necessary*, not optional, because other
|
|
|
|
* backends could have added tuples to these pages whilst we were
|
|
|
|
* vacuuming.
|
2001-07-14 00:55:59 +02:00
|
|
|
*/
|
Fix recently-understood problems with handling of XID freezing, particularly
in PITR scenarios. We now WAL-log the replacement of old XIDs with
FrozenTransactionId, so that such replacement is guaranteed to propagate to
PITR slave databases. Also, rather than relying on hint-bit updates to be
preserved, pg_clog is not truncated until all instances of an XID are known to
have been replaced by FrozenTransactionId. Add new GUC variables and
pg_autovacuum columns to allow management of the freezing policy, so that
users can trade off the size of pg_clog against the amount of freezing work
done. Revise the already-existing code that forces autovacuum of tables
approaching the wraparound point to make it more bulletproof; also, revise the
autovacuum logic so that anti-wraparound vacuuming is done per-table rather
than per-database. initdb forced because of changes in pg_class, pg_database,
and pg_autovacuum catalogs. Heikki Linnakangas, Simon Riggs, and Tom Lane.
2006-11-05 23:42:10 +01:00
|
|
|
new_rel_pages = count_nondeletable_pages(onerel, vacrelstats);
|
2001-07-14 00:55:59 +02:00
|
|
|
|
|
|
|
if (new_rel_pages >= old_rel_pages)
|
|
|
|
{
|
|
|
|
/* can't do anything after all */
|
|
|
|
UnlockRelation(onerel, AccessExclusiveLock);
|
2010-02-09 22:43:30 +01:00
|
|
|
return;
|
2001-07-14 00:55:59 +02:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
2010-02-09 22:43:30 +01:00
|
|
|
* Okay to truncate.
|
2001-07-14 00:55:59 +02:00
|
|
|
*/
|
2010-02-09 22:43:30 +01:00
|
|
|
RelationTruncate(onerel, new_rel_pages);
|
2008-12-17 10:15:03 +01:00
|
|
|
|
2007-09-20 23:43:27 +02:00
|
|
|
/*
|
2010-02-26 03:01:40 +01:00
|
|
|
* We can release the exclusive lock as soon as we have truncated. Other
|
2010-02-09 22:43:30 +01:00
|
|
|
* backends can't safely access the relation until they have processed the
|
|
|
|
* smgr invalidation that smgrtruncate sent out ... but that should happen
|
|
|
|
* as part of standard invalidation processing once they acquire lock on
|
|
|
|
* the relation.
|
2007-09-20 23:43:27 +02:00
|
|
|
*/
|
2010-02-09 22:43:30 +01:00
|
|
|
UnlockRelation(onerel, AccessExclusiveLock);
|
2007-09-10 23:40:03 +02:00
|
|
|
|
Fix VACUUM so that it always updates pg_class.reltuples/relpages.
When we added the ability for vacuum to skip heap pages by consulting the
visibility map, we made it just not update the reltuples/relpages
statistics if it skipped any pages. But this could leave us with extremely
out-of-date stats for a table that contains any unchanging areas,
especially for TOAST tables which never get processed by ANALYZE. In
particular this could result in autovacuum making poor decisions about when
to process the table, as in recent report from Florian Helmberger. And in
general it's a bad idea to not update the stats at all. Instead, use the
previous values of reltuples/relpages as an estimate of the tuple density
in unvisited pages. This approach results in a "moving average" estimate
of reltuples, which should converge to the correct value over multiple
VACUUM and ANALYZE cycles even when individual measurements aren't very
good.
This new method for updating reltuples is used by both VACUUM and ANALYZE,
with the result that we no longer need the grotty interconnections that
caused ANALYZE to not update the stats depending on what had happened
in the parent VACUUM command.
Also, fix the logic for skipping all-visible pages during VACUUM so that it
looks ahead rather than behind to decide what to do, as per a suggestion
from Greg Stark. This eliminates useless scanning of all-visible pages at
the start of the relation or just after a not-all-visible page. In
particular, the first few pages of the relation will not be invariably
included in the scanned pages, which seems to help in not overweighting
them in the reltuples estimate.
Back-patch to 8.4, where the visibility map was introduced.
2011-05-30 23:05:26 +02:00
|
|
|
/*
|
|
|
|
* Update statistics. Here, it *is* correct to adjust rel_pages without
|
|
|
|
* also touching reltuples, since the tuple count wasn't changed by the
|
|
|
|
* truncation.
|
|
|
|
*/
|
2004-12-01 20:00:56 +01:00
|
|
|
vacrelstats->rel_pages = new_rel_pages;
|
|
|
|
vacrelstats->pages_removed = old_rel_pages - new_rel_pages;
|
|
|
|
|
2003-07-20 23:56:35 +02:00
|
|
|
ereport(elevel,
|
|
|
|
(errmsg("\"%s\": truncated %u to %u pages",
|
|
|
|
RelationGetRelationName(onerel),
|
|
|
|
old_rel_pages, new_rel_pages),
|
2005-10-04 00:52:26 +02:00
|
|
|
errdetail("%s.",
|
|
|
|
pg_rusage_show(&ru0))));
|
2001-07-14 00:55:59 +02:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
2007-09-16 04:37:46 +02:00
|
|
|
* Rescan end pages to verify that they are (still) empty of tuples.
|
2001-07-14 00:55:59 +02:00
|
|
|
*
|
|
|
|
* Returns number of nondeletable pages (last nonempty page + 1).
|
|
|
|
*/
|
|
|
|
static BlockNumber
|
Fix recently-understood problems with handling of XID freezing, particularly
in PITR scenarios. We now WAL-log the replacement of old XIDs with
FrozenTransactionId, so that such replacement is guaranteed to propagate to
PITR slave databases. Also, rather than relying on hint-bit updates to be
preserved, pg_clog is not truncated until all instances of an XID are known to
have been replaced by FrozenTransactionId. Add new GUC variables and
pg_autovacuum columns to allow management of the freezing policy, so that
users can trade off the size of pg_clog against the amount of freezing work
done. Revise the already-existing code that forces autovacuum of tables
approaching the wraparound point to make it more bulletproof; also, revise the
autovacuum logic so that anti-wraparound vacuuming is done per-table rather
than per-database. initdb forced because of changes in pg_class, pg_database,
and pg_autovacuum catalogs. Heikki Linnakangas, Simon Riggs, and Tom Lane.
2006-11-05 23:42:10 +01:00
|
|
|
count_nondeletable_pages(Relation onerel, LVRelStats *vacrelstats)
|
2001-07-14 00:55:59 +02:00
|
|
|
{
|
|
|
|
BlockNumber blkno;
|
|
|
|
|
|
|
|
/* Strange coding of loop control is needed because blkno is unsigned */
|
|
|
|
blkno = vacrelstats->rel_pages;
|
|
|
|
while (blkno > vacrelstats->nonempty_pages)
|
|
|
|
{
|
|
|
|
Buffer buf;
|
|
|
|
Page page;
|
|
|
|
OffsetNumber offnum,
|
|
|
|
maxoff;
|
2007-09-16 04:37:46 +02:00
|
|
|
bool hastup;
|
2001-07-14 00:55:59 +02:00
|
|
|
|
2007-09-10 19:58:45 +02:00
|
|
|
/*
|
|
|
|
* We don't insert a vacuum delay point here, because we have an
|
2007-11-15 22:14:46 +01:00
|
|
|
* exclusive lock on the table which we want to hold for as short a
|
|
|
|
* time as possible. We still need to check for interrupts however.
|
2007-09-10 19:58:45 +02:00
|
|
|
*/
|
2007-09-12 04:05:48 +02:00
|
|
|
CHECK_FOR_INTERRUPTS();
|
2004-02-06 20:36:18 +01:00
|
|
|
|
2001-07-14 00:55:59 +02:00
|
|
|
blkno--;
|
|
|
|
|
Unite ReadBufferWithFork, ReadBufferWithStrategy, and ZeroOrReadBuffer
functions into one ReadBufferExtended function, that takes the strategy
and mode as argument. There's three modes, RBM_NORMAL which is the default
used by plain ReadBuffer(), RBM_ZERO, which replaces ZeroOrReadBuffer, and
a new mode RBM_ZERO_ON_ERROR, which allows callers to read corrupt pages
without throwing an error. The FSM needs the new mode to recover from
corrupt pages, which could happend if we crash after extending an FSM file,
and the new page is "torn".
Add fork number to some error messages in bufmgr.c, that still lacked it.
2008-10-31 16:05:00 +01:00
|
|
|
buf = ReadBufferExtended(onerel, MAIN_FORKNUM, blkno,
|
|
|
|
RBM_NORMAL, vac_strategy);
|
2001-07-14 00:55:59 +02:00
|
|
|
|
|
|
|
/* In this phase we only need shared access to the buffer */
|
|
|
|
LockBuffer(buf, BUFFER_LOCK_SHARE);
|
|
|
|
|
|
|
|
page = BufferGetPage(buf);
|
|
|
|
|
|
|
|
if (PageIsNew(page) || PageIsEmpty(page))
|
|
|
|
{
|
2004-04-26 01:50:58 +02:00
|
|
|
/* PageIsNew probably shouldn't happen... */
|
2006-04-01 01:32:07 +02:00
|
|
|
UnlockReleaseBuffer(buf);
|
2001-07-14 00:55:59 +02:00
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
|
|
|
hastup = false;
|
|
|
|
maxoff = PageGetMaxOffsetNumber(page);
|
|
|
|
for (offnum = FirstOffsetNumber;
|
|
|
|
offnum <= maxoff;
|
|
|
|
offnum = OffsetNumberNext(offnum))
|
|
|
|
{
|
|
|
|
ItemId itemid;
|
|
|
|
|
|
|
|
itemid = PageGetItemId(page, offnum);
|
|
|
|
|
2007-09-16 04:37:46 +02:00
|
|
|
/*
|
|
|
|
* Note: any non-unused item should be taken as a reason to keep
|
|
|
|
* this page. We formerly thought that DEAD tuples could be
|
|
|
|
* thrown away, but that's not so, because we'd not have cleaned
|
|
|
|
* out their index entries.
|
|
|
|
*/
|
|
|
|
if (ItemIdIsUsed(itemid))
|
2001-07-14 00:55:59 +02:00
|
|
|
{
|
|
|
|
hastup = true;
|
|
|
|
break; /* can stop scanning */
|
|
|
|
}
|
2001-10-25 07:50:21 +02:00
|
|
|
} /* scan along page */
|
2001-07-14 00:55:59 +02:00
|
|
|
|
2006-04-01 01:32:07 +02:00
|
|
|
UnlockReleaseBuffer(buf);
|
2001-07-14 00:55:59 +02:00
|
|
|
|
|
|
|
/* Done scanning if we found a tuple here */
|
|
|
|
if (hastup)
|
|
|
|
return blkno + 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* If we fall out of the loop, all the previously-thought-to-be-empty
|
2007-09-16 04:37:46 +02:00
|
|
|
* pages still are; we need not bother to look at the last known-nonempty
|
2005-10-15 04:49:52 +02:00
|
|
|
* page.
|
2001-07-14 00:55:59 +02:00
|
|
|
*/
|
|
|
|
return vacrelstats->nonempty_pages;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* lazy_space_alloc - space allocation decisions for lazy vacuum
|
|
|
|
*
|
|
|
|
* See the comments at the head of this file for rationale.
|
|
|
|
*/
|
|
|
|
static void
|
2006-09-13 19:47:08 +02:00
|
|
|
lazy_space_alloc(LVRelStats *vacrelstats, BlockNumber relblocks)
|
2001-07-14 00:55:59 +02:00
|
|
|
{
|
2005-08-21 01:26:37 +02:00
|
|
|
long maxtuples;
|
2001-07-14 00:55:59 +02:00
|
|
|
|
2006-09-13 19:47:08 +02:00
|
|
|
if (vacrelstats->hasindex)
|
|
|
|
{
|
2006-09-04 23:40:23 +02:00
|
|
|
maxtuples = (maintenance_work_mem * 1024L) / sizeof(ItemPointerData);
|
|
|
|
maxtuples = Min(maxtuples, INT_MAX);
|
|
|
|
maxtuples = Min(maxtuples, MaxAllocSize / sizeof(ItemPointerData));
|
2007-09-24 05:52:55 +02:00
|
|
|
|
|
|
|
/* curious coding here to ensure the multiplication can't overflow */
|
|
|
|
if ((BlockNumber) (maxtuples / LAZY_ALLOC_TUPLES) > relblocks)
|
|
|
|
maxtuples = relblocks * LAZY_ALLOC_TUPLES;
|
|
|
|
|
2006-09-04 23:40:23 +02:00
|
|
|
/* stay sane if small maintenance_work_mem */
|
|
|
|
maxtuples = Max(maxtuples, MaxHeapTuplesPerPage);
|
2006-09-13 19:47:08 +02:00
|
|
|
}
|
|
|
|
else
|
|
|
|
{
|
2006-09-04 23:40:23 +02:00
|
|
|
maxtuples = MaxHeapTuplesPerPage;
|
|
|
|
}
|
2001-07-14 00:55:59 +02:00
|
|
|
|
|
|
|
vacrelstats->num_dead_tuples = 0;
|
2005-08-21 01:26:37 +02:00
|
|
|
vacrelstats->max_dead_tuples = (int) maxtuples;
|
2001-07-14 00:55:59 +02:00
|
|
|
vacrelstats->dead_tuples = (ItemPointer)
|
|
|
|
palloc(maxtuples * sizeof(ItemPointerData));
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* lazy_record_dead_tuple - remember one deletable tuple
|
|
|
|
*/
|
|
|
|
static void
|
|
|
|
lazy_record_dead_tuple(LVRelStats *vacrelstats,
|
|
|
|
ItemPointer itemptr)
|
|
|
|
{
|
|
|
|
/*
|
2001-10-25 07:50:21 +02:00
|
|
|
* The array shouldn't overflow under normal behavior, but perhaps it
|
2004-02-03 18:34:04 +01:00
|
|
|
* could if we are given a really small maintenance_work_mem. In that
|
2007-09-20 19:56:33 +02:00
|
|
|
* case, just forget the last few tuples (we'll get 'em next time).
|
2001-07-14 00:55:59 +02:00
|
|
|
*/
|
|
|
|
if (vacrelstats->num_dead_tuples < vacrelstats->max_dead_tuples)
|
|
|
|
{
|
|
|
|
vacrelstats->dead_tuples[vacrelstats->num_dead_tuples] = *itemptr;
|
|
|
|
vacrelstats->num_dead_tuples++;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* lazy_tid_reaped() -- is a particular tid deletable?
|
|
|
|
*
|
Restructure index AM interface for index building and index tuple deletion,
per previous discussion on pghackers. Most of the duplicate code in
different AMs' ambuild routines has been moved out to a common routine
in index.c; this means that all index types now do the right things about
inserting recently-dead tuples, etc. (I also removed support for EXTEND
INDEX in the ambuild routines, since that's about to go away anyway, and
it cluttered the code a lot.) The retail indextuple deletion routines have
been replaced by a "bulk delete" routine in which the indexscan is inside
the access method. I haven't pushed this change as far as it should go yet,
but it should allow considerable simplification of the internal bookkeeping
for deletions. Also, add flag columns to pg_am to eliminate various
hardcoded tests on AM OIDs, and remove unused pg_am columns.
Fix rtree and gist index types to not attempt to store NULLs; before this,
gist usually crashed, while rtree managed not to crash but computed wacko
bounding boxes for NULL entries (which might have had something to do with
the performance problems we've heard about occasionally).
Add AtEOXact routines to hash, rtree, and gist, all of which have static
state that needs to be reset after an error. We discovered this need long
ago for btree, but missed the other guys.
Oh, one more thing: concurrent VACUUM is now the default.
2001-07-16 00:48:19 +02:00
|
|
|
* This has the right signature to be an IndexBulkDeleteCallback.
|
|
|
|
*
|
2001-07-14 00:55:59 +02:00
|
|
|
* Assumes dead_tuples array is in sorted order.
|
|
|
|
*/
|
|
|
|
static bool
|
Restructure index AM interface for index building and index tuple deletion,
per previous discussion on pghackers. Most of the duplicate code in
different AMs' ambuild routines has been moved out to a common routine
in index.c; this means that all index types now do the right things about
inserting recently-dead tuples, etc. (I also removed support for EXTEND
INDEX in the ambuild routines, since that's about to go away anyway, and
it cluttered the code a lot.) The retail indextuple deletion routines have
been replaced by a "bulk delete" routine in which the indexscan is inside
the access method. I haven't pushed this change as far as it should go yet,
but it should allow considerable simplification of the internal bookkeeping
for deletions. Also, add flag columns to pg_am to eliminate various
hardcoded tests on AM OIDs, and remove unused pg_am columns.
Fix rtree and gist index types to not attempt to store NULLs; before this,
gist usually crashed, while rtree managed not to crash but computed wacko
bounding boxes for NULL entries (which might have had something to do with
the performance problems we've heard about occasionally).
Add AtEOXact routines to hash, rtree, and gist, all of which have static
state that needs to be reset after an error. We discovered this need long
ago for btree, but missed the other guys.
Oh, one more thing: concurrent VACUUM is now the default.
2001-07-16 00:48:19 +02:00
|
|
|
lazy_tid_reaped(ItemPointer itemptr, void *state)
|
2001-07-14 00:55:59 +02:00
|
|
|
{
|
Restructure index AM interface for index building and index tuple deletion,
per previous discussion on pghackers. Most of the duplicate code in
different AMs' ambuild routines has been moved out to a common routine
in index.c; this means that all index types now do the right things about
inserting recently-dead tuples, etc. (I also removed support for EXTEND
INDEX in the ambuild routines, since that's about to go away anyway, and
it cluttered the code a lot.) The retail indextuple deletion routines have
been replaced by a "bulk delete" routine in which the indexscan is inside
the access method. I haven't pushed this change as far as it should go yet,
but it should allow considerable simplification of the internal bookkeeping
for deletions. Also, add flag columns to pg_am to eliminate various
hardcoded tests on AM OIDs, and remove unused pg_am columns.
Fix rtree and gist index types to not attempt to store NULLs; before this,
gist usually crashed, while rtree managed not to crash but computed wacko
bounding boxes for NULL entries (which might have had something to do with
the performance problems we've heard about occasionally).
Add AtEOXact routines to hash, rtree, and gist, all of which have static
state that needs to be reset after an error. We discovered this need long
ago for btree, but missed the other guys.
Oh, one more thing: concurrent VACUUM is now the default.
2001-07-16 00:48:19 +02:00
|
|
|
LVRelStats *vacrelstats = (LVRelStats *) state;
|
2001-10-25 07:50:21 +02:00
|
|
|
ItemPointer res;
|
2001-07-14 00:55:59 +02:00
|
|
|
|
|
|
|
res = (ItemPointer) bsearch((void *) itemptr,
|
|
|
|
(void *) vacrelstats->dead_tuples,
|
|
|
|
vacrelstats->num_dead_tuples,
|
|
|
|
sizeof(ItemPointerData),
|
|
|
|
vac_cmp_itemptr);
|
|
|
|
|
|
|
|
return (res != NULL);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Comparator routines for use with qsort() and bsearch().
|
|
|
|
*/
|
|
|
|
static int
|
|
|
|
vac_cmp_itemptr(const void *left, const void *right)
|
|
|
|
{
|
|
|
|
BlockNumber lblk,
|
|
|
|
rblk;
|
|
|
|
OffsetNumber loff,
|
|
|
|
roff;
|
|
|
|
|
|
|
|
lblk = ItemPointerGetBlockNumber((ItemPointer) left);
|
|
|
|
rblk = ItemPointerGetBlockNumber((ItemPointer) right);
|
|
|
|
|
|
|
|
if (lblk < rblk)
|
|
|
|
return -1;
|
|
|
|
if (lblk > rblk)
|
|
|
|
return 1;
|
|
|
|
|
|
|
|
loff = ItemPointerGetOffsetNumber((ItemPointer) left);
|
|
|
|
roff = ItemPointerGetOffsetNumber((ItemPointer) right);
|
|
|
|
|
|
|
|
if (loff < roff)
|
|
|
|
return -1;
|
|
|
|
if (loff > roff)
|
|
|
|
return 1;
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|