All such code deals with this global variable in one of three ways.
Sometimes the same functions use it in more than one of these ways
at the same time.
First, sometimes it's an implicit argument to one or more functions
being called in xlog.c or elsewhere, and must be set to the
appropriate value before calling those functions lest they
misbehave. In those cases, it is now passed as an explicit argument
instead.
Second, sometimes it's used to obtain the current timeline after
the end of recovery, i.e. the timeline to which WAL is being
written and flushed. Such code now calls GetWALInsertionTimeLine()
or relies on the new out parameter added to GetFlushRecPtr().
Third, sometimes it's used during recovery to store the current
replay timeline. That can change, so such code must generally
update the value before each use. It can still do that, but must
now use a local variable instead.
The net effect of these changes is to reduce by a fair amount the
amount of code that is directly accessing this global variable.
That's good, because history has shown that we don't always think
clearly about which timeline ID it's supposed to contain at any
given point in time, or indeed, whether it has been or needs to
be initialized at any given point in the code.
Patch by me, reviewed and tested by Michael Paquier, Amul Sul, and
Álvaro Herrera.
Discussion: https://postgr.es/m/CA+TgmobfAAqhfWa1kaFBBFvX+5CjM=7TE=n4r4Q1o2bjbGYBpA@mail.gmail.com
The base backup code has accumulated a healthy number of new
features over the years, but it's becoming increasingly difficult
to maintain and further enhance that code because there's no
real separation of concerns. For example, the code that
understands knows the details of how we send data to the client
using the libpq protocol is scattered throughout basebackup.c,
rather than being centralized in one place.
To try to improve this situation, introduce a new 'bbsink' object
which acts as a recipient for archives generated during the base
backup progress and also for the backup manifest. This commit
introduces three types of bbsink: a 'copytblspc' bbsink forwards the
backup to the client using one COPY OUT operation per tablespace and
another for the manifest, a 'progress' bbsink performs command
progress reporting, and a 'throttle' bbsink performs rate-limiting.
The 'progress' and 'throttle' bbsink types also forward the data to a
successor bbsink; at present, the last bbsink in the chain will
always be of type 'copytblspc'. There are plans to add more types
of 'bbsink' in future commits.
This abstraction is a bit leaky in the case of progress reporting,
but this still seems cleaner than what we had before.
Patch by me, reviewed and tested by Andres Freund, Sumanta Mukherjee,
Dilip Kumar, Suraj Kharage, Dipesh Pandit, Tushar Ahuja, Mark Dilger,
and Jeevan Ladhe.
Discussion: https://postgr.es/m/CA+TgmoZGwR=ZVWFeecncubEyPdwghnvfkkdBe9BLccLSiqdf9Q@mail.gmail.com
Discussion: https://postgr.es/m/CA+TgmoZvqk7UuzxsX1xjJRmMGkqoUGYTZLDCH8SmU1xTPr1Xig@mail.gmail.com
Add hardening to the heapam index tuple deletion path to catch TIDs in
index pages that point to a heap item that index tuples should never
point to. The corruption we're trying to catch here is particularly
tricky to detect, since it typically involves "extra" (corrupt) index
tuples, as opposed to the absence of required index tuples in the index.
For example, a heap TID from an index page that turns out to point to an
LP_UNUSED item in the heap page has a good chance of being caught by one
of the new checks. There is a decent chance that the recently fixed
parallel VACUUM bug (see commit 9bacec15) would have been caught had
that particular check been in place for Postgres 14. No backpatch of
this extra hardening for now, though.
Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CAH2-Wzk-4_raTzawWGaiqNvkpwDXxv3y1AQhQyUeHfkU=tFCeA@mail.gmail.com
Commit b4af70cb, which simplified state managed by VACUUM, performed
refactoring of parallel VACUUM in passing. Confusion about the exact
details of the tasks that the leader process is responsible for led to
code that made it possible for parallel VACUUM to miss a subset of the
table's indexes entirely. Specifically, indexes that fell under the
min_parallel_index_scan_size size cutoff were missed. These indexes are
supposed to be vacuumed by the leader (alongside any parallel unsafe
indexes), but weren't vacuumed at all. Affected indexes could easily
end up with duplicate heap TIDs, once heap TIDs were recycled for new
heap tuples. This had generic symptoms that might be seen with almost
any index corruption involving structural inconsistencies between an
index and its table.
To fix, make sure that the parallel VACUUM leader process performs any
required index vacuuming for indexes that happen to be below the size
cutoff. Also document the design of parallel VACUUM with these
below-size-cutoff indexes.
It's unclear how many users might be affected by this bug. There had to
be at least three indexes on the table to hit the bug: a smaller index,
plus at least two additional indexes that themselves exceed the size
cutoff. Cases with just one additional index would not run into
trouble, since the parallel VACUUM cost model requires two
larger-than-cutoff indexes on the table to apply any parallel
processing. Note also that autovacuum was not affected, since it never
uses parallel processing.
Test case based on tests from a larger patch to test parallel VACUUM by
Masahiko Sawada.
Many thanks to Kamigishi Rei for her invaluable help with tracking this
problem down.
Author: Peter Geoghegan <pg@bowt.ie>
Author: Masahiko Sawada <sawada.mshk@gmail.com>
Reported-By: Kamigishi Rei <iijima.yun@koumakan.jp>
Reported-By: Andrew Gierth <andrew@tao11.riddles.org.uk>
Diagnosed-By: Andres Freund <andres@anarazel.de>
Bug: #17245
Discussion: https://postgr.es/m/17245-ddf06aaf85735f36@postgresql.org
Discussion: https://postgr.es/m/20211030023740.qbnsl2xaoh2grq3d@alap3.anarazel.de
Backpatch: 14-, where the refactoring commit appears.
As in commits 6301c3ada and e9d9ba2a4, avoid doing repetitive
list_delete_first() operations, since that would be expensive when
there are many files waiting to be unlinked. This is a slightly
larger change than in those cases. We have to keep the list state
valid for calls to AbsorbSyncRequests(), so it's necessary to invent a
"canceled" field instead of immediately deleting PendingUnlinkEntry
entries. Also, because we might not be able to process all the
entries, we need a new list primitive list_delete_first_n().
list_delete_first_n() is almost list_copy_tail(), but it modifies the
input List instead of making a new copy. I found a couple of existing
uses of the latter that could profitably use the new function. (There
might be more, but the other callers look like they probably shouldn't
overwrite the input List.)
As before, back-patch to v13.
Discussion: https://postgr.es/m/CD2F0E7F-9822-45EC-A411-AE56F14DEA9F@amazon.com
Commit 0bead9af48 introduced XLOG_INCLUDE_XID flag to indicate that the
WAL record contains subXID-to-topXID association. It uses that flag later
to mark in CurrentTransactionState that top-xid is logged so that we
should not try to log it again with the next WAL record in the current
subtransaction. However, we can use a localized variable to pass that
information.
In passing, change the related function and variable names to make them
consistent with what the code is actually doing.
Author: Dilip Kumar
Reviewed-by: Alvaro Herrera, Amit Kapila
Discussion: https://postgr.es/m/E1mSoYz-0007Fh-D9@gemulon.postgresql.org
Grant privileges on views pg_backend_memory_contexts and
pg_shmem_allocations to the role pg_read_all_stats. Also grant on the
underlying functions that those views depend on.
Author: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Reviewed-by: Nathan Bossart <bossartn@amazon.com>
Discussion: https://postgr.es/m/CALj2ACWAZo3Ar_EVsn2Zf9irG+hYK3cmh1KWhZS_Od45nd01RA@mail.gmail.com
A new option "FOR ALL TABLES IN SCHEMA" in Create/Alter Publication allows
one or more schemas to be specified, whose tables are selected by the
publisher for sending the data to the subscriber.
The new syntax allows specifying both the tables and schemas. For example:
CREATE PUBLICATION pub1 FOR TABLE t1,t2,t3, ALL TABLES IN SCHEMA s1,s2;
OR
ALTER PUBLICATION pub1 ADD TABLE t1,t2,t3, ALL TABLES IN SCHEMA s1,s2;
A new system table "pg_publication_namespace" has been added, to maintain
the schemas that the user wants to publish through the publication.
Modified the output plugin (pgoutput) to publish the changes if the
relation is part of schema publication.
Updates pg_dump to identify and dump schema publications. Updates the \d
family of commands to display schema publications and \dRp+ variant will
now display associated schemas if any.
Author: Vignesh C, Hou Zhijie, Amit Kapila
Syntax-Suggested-by: Tom Lane, Alvaro Herrera
Reviewed-by: Greg Nancarrow, Masahiko Sawada, Hou Zhijie, Amit Kapila, Haiying Tang, Ajin Cherian, Rahila Syed, Bharath Rupireddy, Mark Dilger
Tested-by: Haiying Tang
Discussion: https://www.postgresql.org/message-id/CALDaNm0OANxuJ6RXqwZsM1MSY4s19nuH3734j4a72etDwvBETQ@mail.gmail.com
Remove superuser check, allowing any user granted permissions on
pg_log_backend_memory_contexts() to log the memory contexts of any
backend.
Note that this could allow a privileged non-superuser to log the
memory contexts of a superuser backend, but as discussed, that does
not seem to be a problem.
Reviewed-by: Nathan Bossart, Bharath Rupireddy, Michael Paquier, Kyotaro Horiguchi, Andres Freund
Discussion: https://postgr.es/m/e5cf6684d17c8d1ef4904ae248605ccd6da03e72.camel@j-davis.com
Users sometimes get concerned whe they start the server and it
emits a few messages and then doesn't emit any more messages for
a long time. Generally, what's happening is either that the
system is taking a long time to apply WAL, or it's taking a
long time to reset unlogged relations, or it's taking a long
time to fsync the data directory, but it's not easy to tell
which is the case.
To fix that, add a new 'log_startup_progress_interval' setting,
by default 10s. When an operation that is known to be potentially
long-running takes more than this amount of time, we'll log a
status update each time this interval elapses.
To avoid undesirable log chatter, don't log anything about WAL
replay when in standby mode.
Nitin Jadhav and Robert Haas, reviewed by Amul Sul, Bharath
Rupireddy, Justin Pryzby, Michael Paquier, and Álvaro Herrera.
Discussion: https://postgr.es/m/CA+TgmoaHQrgDFOBwgY16XCoMtXxsrVGFB2jNCvb7-ubuEe1MGg@mail.gmail.com
Discussion: https://postgr.es/m/CAMm1aWaHF7VE69572_OLQ+MgpT5RUiUDgF1x5RrtkJBLdpRj3Q@mail.gmail.com
The command is supported for physical slots for now, and returns the
type of slot, its restart_lsn and its restart_tli.
This will be useful for an upcoming patch related to pg_receivewal, to
allow the tool to be able to stream from the position of a slot, rather
than the last WAL position flushed by the backend (as reported by
IDENTIFY_SYSTEM) if the archive directory is found as empty, which would
be an advantage in the case of switching to a different archive
locations with the same slot used to avoid holes in WAL segment
archives.
Author: Ronan Dunklau
Reviewed-by: Kyotaro Horiguchi, Michael Paquier, Bharath Rupireddy
Discussion: https://postgr.es/m/18708360.4lzOvYHigE@aivenronan
The purpose of commit 8a54e12a38 was to
fix this, and it sufficed when the PREPARE TRANSACTION completed before
the CIC looked for lock conflicts. Otherwise, things still broke. As
before, in a cluster having used CIC while having enabled prepared
transactions, queries that use the resulting index can silently fail to
find rows. It may be necessary to reindex to recover from past
occurrences; REINDEX CONCURRENTLY suffices. Fix this for future index
builds by making CIC wait for arbitrarily-recent prepared transactions
and for ordinary transactions that may yet PREPARE TRANSACTION. As part
of that, have PREPARE TRANSACTION transfer locks to its dummy PGPROC
before it calls ProcArrayClearTransaction(). Back-patch to 9.6 (all
supported versions).
Andrey Borodin, reviewed (in earlier versions) by Andres Freund.
Discussion: https://postgr.es/m/01824242-AA92-4FE9-9BA7-AEBAFFEA3D0C@yandex-team.ru
CIC and REINDEX CONCURRENTLY assume backends see their catalog changes
no later than each backend's next transaction start. That failed to
hold when a backend absorbed a relevant invalidation in the middle of
running RelationBuildDesc() on the CIC index. Queries that use the
resulting index can silently fail to find rows. Fix this for future
index builds by making RelationBuildDesc() loop until it finishes
without accepting a relevant invalidation. It may be necessary to
reindex to recover from past occurrences; REINDEX CONCURRENTLY suffices.
Back-patch to 9.6 (all supported versions).
Noah Misch and Andrey Borodin, reviewed (in earlier versions) by Andres
Freund.
Discussion: https://postgr.es/m/20210730022548.GA1940096@gust.leadboat.com
The code does not expect sh_error() to return, but the patch
that made this header usable in frontend didn't get that memo.
While here, plaster unlikely() on the tests that decide whether
to invoke sh_error(), and add our standard copyright notice.
Noted by Andres Freund. Back-patch to v13 where this frontend
support came in.
Discussion: https://postgr.es/m/0D54435C-1199-4361-9D74-2FBDCF8EA164@anarazel.de
I just got burnt by trying to use pg_malloc instead of pg_malloc0
with this. Save the next hacker some time by not leaving this
API detail undocumented.
All the tape functions, like LogicalTapeRead and LogicalTapeWrite, now
take a LogicalTape as argument, instead of LogicalTapeSet+tape number.
You can create any number of LogicalTapes in a single LogicalTapeSet, and
you don't need to decide the number upfront, when you create the tape set.
This makes the tape management in hash agg spilling in nodeAgg.c simpler.
Discussion: https://www.postgresql.org/message-id/420a0ec7-602c-d406-1e75-1ef7ddc58d83%40iki.fi
Reviewed-by: Peter Geoghegan, Zhihong Yu, John Naylor
During a replication slot creation, an ERROR generated in the same
transaction as the one creating a to-be-exported snapshot would have
left the backend in an inconsistent state, as the associated static
export snapshot state was not being reset on transaction abort, but only
on the follow-up command received by the WAL sender that created this
snapshot on replication slot creation. This would trigger inconsistency
failures if this session tried to export again a snapshot, like during
the creation of a replication slot.
Note that a snapshot export cannot happen in a transaction block, so
there is no need to worry resetting this state for subtransaction
aborts. Also, this inconsistent state would very unlikely show up to
users. For example, one case where this could happen is an
out-of-memory error when building the initial snapshot to-be-exported.
Dilip found this problem while poking at a different patch, that caused
an error in this code path for reasons unrelated to HEAD.
Author: Dilip Kumar
Reviewed-by: Michael Paquier, Zhihong Yu
Discussion: https://postgr.es/m/CAFiTN-s0zA1Kj0ozGHwkYkHwa5U0zUE94RSc_g81WrpcETB5=w@mail.gmail.com
Backpatch-through: 9.6
Do not update shm_mq's mq_bytes_written until we have written
an amount of data greater than 1/4th of the ring size, unless
the caller of shm_mq_send(v) requests a flush at the end of
the message. This reduces the number of calls to SetLatch(),
and also the number of CPU cache misses, considerably, and thus
makes shm_mq significantly faster.
Dilip Kumar, reviewed by Zhihong Yu and Tomas Vondra. Some
minor cosmetic changes by me.
Discussion: http://postgr.es/m/CAFiTN-tVXqn_OG7tHNeSkBbN+iiCZTiQ83uakax43y1sQb2OBA@mail.gmail.com
windows.h includes a lot of other headers, slowing down compilation
significantly. WIN32_LEAN_AND_MEAN reduces that a bit. It'd be better to
remove the include of windows.h (as well as indirect inclusions of it) from such
a central place, but until then...
Discussion: https://postgr.es/m/20210921193035.pqzay43vpyv7in43@alap3.anarazel.de
Prior to v14, we insisted that the query in RETURN QUERY be of a type
that returns tuples. (For instance, INSERT RETURNING was allowed,
but not plain INSERT.) That happened indirectly because we opened a
cursor for the query, so spi.c checked SPI_is_cursor_plan(). As a
consequence, the error message wasn't terribly on-point, but at least
it was there.
Commit 2f48ede08 lost this detail. Instead, plain RETURN QUERY
insisted that the query be a SELECT (by checking for SPI_OK_SELECT)
while RETURN QUERY EXECUTE failed to check the query type at all.
Neither of these changes was intended.
The only convenient place to check this in the EXECUTE case is inside
_SPI_execute_plan, because we haven't done parse analysis until then.
So we need to pass down a flag saying whether to enforce that the
query returns tuples. Fortunately, we can squeeze another boolean
into struct SPIExecuteOptions without an ABI break, since there's
padding space there. (It's unlikely that any extensions would
already be using this new struct, but preserving ABI in v14 seems
like a smart idea anyway.)
Within spi.c, it seemed like _SPI_execute_plan's parameter list
was already ridiculously long, and I didn't want to make it longer.
So I thought of passing SPIExecuteOptions down as-is, allowing that
parameter list to become much shorter. This makes the patch a bit
more invasive than it might otherwise be, but it's all internal to
spi.c, so that seems fine.
Per report from Marc Bachmann. Back-patch to v14 where the
faulty code came in.
Discussion: https://postgr.es/m/1F2F75F0-27DF-406F-848D-8B50C7EEF06A@gmail.com
Commit 84f5c2908 forgot to consider the possibility that
EnsurePortalSnapshotExists could run inside a subtransaction with
lifespan shorter than the Portal's. In that case, the new active
snapshot would be popped at the end of the subtransaction, leaving
a dangling pointer in the Portal, with mayhem ensuing.
To fix, make sure the ActiveSnapshot stack entry is marked with
the same subtransaction nesting level as the associated Portal.
It's certainly safe to do so since we won't be here at all unless
the stack is empty; hence we can't create an out-of-order stack.
Let's also apply this logic in the case where PortalRunUtility
sets portalSnapshot, just to be sure that path can't cause similar
problems. It's slightly less clear that that path can't create
an out-of-order stack, so add an assertion guarding it.
Report and patch by Bertrand Drouvot (with kibitzing by me).
Back-patch to v11, like the previous commit.
Discussion: https://postgr.es/m/ff82b8c5-77f4-3fe7-6028-fcf3303e82dd@amazon.com
This field was recently added in db632fbca, however that commit missed one
place where it should have initialized the new field to NULL. The missed
location is where the PartitionBoundInfo is created for partition-wise
join relations. Technically there could be interleaved partitions in a
partition-wise join relation, but currently the only optimization we use
this field for only does so for base rels and other member rels. So just
document that we don't populate this field for join rels.
Reported-by: Amit Langote
Author: Amit Langote, David Rowley
Reviewed-by: Amit Langote, David Rowley
Discussion: https://postgr.es/m/CA+HiwqE76Rps24kwHsd2Cr82Ua07tJC9t9reG0c7ScX9n_xrEA@mail.gmail.com
Add ETIMEDOUT to ALL_CONNECTION_FAILURE_ERRNOS' list of "errnos that
identify hard failure of a previously-established network connection".
While one could imagine that this is sometimes recoverable, the same
could be said of other entries such as ENETDOWN.
In support of this, handle ETIMEDOUT on par with other socket errors
in relevant infrastructure, such as TranslateSocketError().
(I made a couple of cosmetic adjustments in TranslateSocketError(),
too.) The code now assumes that ETIMEDOUT is defined everywhere,
which it should be given that POSIX has required it since SUSv2.
Perhaps this should be back-patched, but I'm hesitant to do so given
the lack of previous complaints, and the hazard that there's a small
ABI break on Windows from redefining the symbol. Even if we decide
to do that, it'd be prudent to let this bake awhile in HEAD first.
Jelte Fennema
Discussion: https://postgr.es/m/AM5PR83MB01782BFF2978505F6D6C559AF7AA9@AM5PR83MB0178.EURPRD83.prod.outlook.com
Physical replication always ships WAL segment files to replicas once
they are complete. This is a problem if one WAL record is split across
a segment boundary and the primary server crashes before writing down
the segment with the next portion of the WAL record: WAL writing after
crash recovery would happily resume at the point where the broken record
started, overwriting that record ... but any standby or backup may have
already received a copy of that segment, and they are not rewinding.
This causes standbys to stop following the primary after the latter
crashes:
LOG: invalid contrecord length 7262 at A8/D9FFFBC8
because the standby is still trying to read the continuation record
(contrecord) for the original long WAL record, but it is not there and
it will never be. A workaround is to stop the replica, delete the WAL
file, and restart it -- at which point a fresh copy is brought over from
the primary. But that's pretty labor intensive, and I bet many users
would just give up and re-clone the standby instead.
A fix for this problem was already attempted in commit 515e3d84a0, but
it only addressed the case for the scenario of WAL archiving, so
streaming replication would still be a problem (as well as other things
such as taking a filesystem-level backup while the server is down after
having crashed), and it had performance scalability problems too; so it
had to be reverted.
This commit fixes the problem using an approach suggested by Andres
Freund, whereby the initial portion(s) of the split-up WAL record are
kept, and a special type of WAL record is written where the contrecord
was lost, so that WAL replay in the replica knows to skip the broken
parts. With this approach, we can continue to stream/archive segment
files as soon as they are complete, and replay of the broken records
will proceed across the crash point without a hitch.
Because a new type of WAL record is added, users should be careful to
upgrade standbys first, primaries later. Otherwise they risk the standby
being unable to start if the primary happens to write such a record.
A new TAP test that exercises this is added, but the portability of it
is yet to be seen.
This has been wrong since the introduction of physical replication, so
backpatch all the way back. In stable branches, keep the new
XLogReaderState members at the end of the struct, to avoid an ABI
break.
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Reviewed-by: Nathan Bossart <bossartn@amazon.com>
Discussion: https://postgr.es/m/202108232252.dh7uxf6oxwcy@alvherre.pgsql
That allows to include just visibilitymapdefs.h from file.c, and in turn,
remove include of postgres.h from relcache.h.
Reported-by: Andres Freund
Discussion: https://postgr.es/m/20210913232614.czafiubr435l6egi%40alap3.anarazel.de
Author: Alexander Korotkov
Reviewed-by: Andres Freund, Tom Lane, Alvaro Herrera
Backpatch-through: 13
Updates/Deletes on a partition were allowed even without replica identity
after the parent table was added to a publication. This would later lead
to an error on subscribers. The reason was that we were not invalidating
the partition's relcache and the publication information for partitions
was not getting rebuilt. Similarly, we were not invalidating the
partitions' relcache after dropping a partitioned table from a publication
which will prohibit Updates/Deletes on its partition without replica
identity even without any publication.
Reported-by: Haiying Tang
Author: Hou Zhijie and Vignesh C
Reviewed-by: Vignesh C and Amit Kapila
Backpatch-through: 13
Discussion: https://postgr.es/m/OS0PR01MB6113D77F583C922F1CEAA1C3FBD29@OS0PR01MB6113.jpnprd01.prod.outlook.com
It is not appropriate for deduplication to apply single value strategy
when triggered by a bottom-up index deletion pass. This wastes cycles
because later bottom-up deletion passes will overinterpret older
duplicate tuples that deduplication actually just skipped over "by
design". It also makes bottom-up deletion much less effective for low
cardinality indexes that happen to cross a meaningless "index has single
key value per leaf page" threshold.
To fix, slightly narrow the conditions under which deduplication's
single value strategy is considered. We already avoided the strategy
for a unique index, since our high level goal must just be to buy time
for VACUUM to run (not to buy space). We'll now also avoid it when we
just had a bottom-up pass that reported failure. The two cases share
the same high level goal, and already overlapped significantly, so this
approach is quite natural.
Oversight in commit d168b666, which added bottom-up index deletion.
Author: Peter Geoghegan <pg@bowt.ie>
Discussion: https://postgr.es/m/CAH2-WznaOvM+Gyj-JQ0X=JxoMDxctDTYjiEuETdAGbF5EUc3MA@mail.gmail.com
Backpatch: 14-, where bottom-up deletion was introduced.
I noticed that commit 0bead9af48 left this flag undocumented in
XLogSetRecordFlags, which led me to discover that the flag doesn't
actually do what the one comment on it said it does. Improve the
situation by adding some more comments.
Backpatch to 14, where the aforementioned commit appears.
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/202109212119.c3nhfp64t2ql@alvherre.pgsql
This runtime-computed GUC shows the number of huge pages required
for the server's main shared memory area, taking advantage of the
work done in 0c39c29 and 0bd305e. This is useful for users to estimate
the amount of huge pages required for a server as it becomes possible to
do an estimation without having to start the server and potentially
allocate a large chunk of shared memory.
The number of huge pages is calculated based on the existing GUC
huge_page_size if set, or by using the system's default by looking at
/proc/meminfo on Linux. There is nothing new here as this commit reuses
the existing calculation methods, and just exposes this information
directly to the user. The routine calculating the huge page size is
refactored to limit the number of files with platform-specific flags.
This new GUC's name was the most popular choice based on the discussion
done. This is only supported on Linux.
I have taken the time to test the change on Linux, Windows and MacOS,
though for the last two ones large pages are not supported. The first
one calculates correctly the number of pages depending on the existing
GUC huge_page_size or the system's default.
Thanks to Andres Freund, Robert Haas, Kyotaro Horiguchi, Tom Lane,
Justin Pryzby (and anybody forgotten here) for the discussion.
Author: Nathan Bossart
Discussion: https://postgr.es/m/F2772387-CE0F-46BF-B5F1-CC55516EB885@amazon.com
The upcoming shared memory stats patch drops stats for dropped objects in a
transactional manner, rather than removing them later as part of vacuum. This
means that stats for DROP inside a transaction needs to handle aborted
(sub-)transactions similar to TRUNCATE: The stats up to the DROP should be
restored.
Rename the existing infrastructure in preparation.
Author: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20210405092914.mmxqe7j56lsjfsej@alap3.anarazel.de
It was harder than necessary to understand PostgresMain() because the code for
a normal backend was interspersed with single-user mode specific code. Split
most of the single-user mode code into its own function
PostgresSingleUserMain(), that does all the necessary setup for single-user
mode, and then hands off after that to PostgresMain().
There still is some single-user mode code in InitPostgres(), and it'd likely
be worth moving at least some of it out. But that's for later.
Reviewed-By: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Author: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20210802164124.ufo5buo4apl6yuvs@alap3.anarazel.de
Session statistics, as introduced by 960869da08, had several shortcomings:
- an additional GetCurrentTimestamp() call that also impaired the accuracy of
the data collected
This can be avoided by passing the current timestamp we already have in
pgstat_report_stat().
- an additional statistics UDP packet sent every 500ms
This is solved by adding the new statistics to PgStat_MsgTabstat.
This is conceptually ugly, because session statistics are not
table statistics. But the struct already contains data unrelated
to tables, so there is not much damage done.
Connection and disconnection are reported in separate messages, which
reduces the number of additional messages to two messages per session and a
slight increase in PgStat_MsgTabstat size (but the same number of table
stats fit).
- Session time computation could overflow on systems where long is 32 bit.
Reported-By: Andres Freund <andres@anarazel.de>
Author: Andres Freund <andres@anarazel.de>
Author: Laurenz Albe <laurenz.albe@cybertec.at>
Discussion: https://postgr.es/m/20210801205501.nyxzxoelqoo4x2qc%40alap3.anarazel.de
Backpatch: 14-, where the feature was introduced.
Until now, the -C option of postgres was handled before a small subset
of GUCs computed at runtime are initialized, leading to incorrect
results as GUC machinery would fall back to default values for such
parameters.
For example, data_checksums could report "off" for a cluster as the
control file is not loaded yet. Or wal_segment_size would show a
segment size at 16MB even if initdb --wal-segsize used something else.
Worse, the command would fail to properly report the recently-introduced
shared_memory, that requires to load shared_preload_libraries as these
could ask for a chunk of shared memory.
Support for runtime GUCs comes with a limitation, as the operation is
now allowed on a running server. One notable reason for this is that
_PG_init() functions of loadable libraries are called before all
runtime-computed GUCs are initialized, and this is not guaranteed to be
safe to do on running servers. For the case of shared_memory_size,
where we want to know how much memory would be used without allocating
it, this limitation is fine. Another case where this will help is for
huge pages, with the introduction of a different GUC to evaluate the
amount of huge pages required for a server before starting it, without
having to allocate large chunks of memory.
This feature is controlled with a new GUC flag, and four parameters are
classified as runtime-computed as of this change:
- data_checksums
- shared_memory_size
- data_directory_mode
- wal_segment_size
Some TAP tests are added to provide some coverage here, using
data_checksums in the tests of pg_checksums.
Per discussion with Andres Freund, Justin Pryzby, Magnus Hagander and
more.
Author: Nathan Bossart
Discussion: https://postgr.es/m/F2772387-CE0F-46BF-B5F1-CC55516EB885@amazon.com
Up to now the size of a query's rangetable has been limited by the
constants INNER_VAR et al, which mustn't be equal to any real
rangetable index. 65000 doubtless seemed like enough for anybody,
and it still is orders of magnitude larger than the number of joins
we can realistically handle. However, we need a rangetable entry
for each child partition that is (or might be) processed by a query.
Queries with a few thousand partitions are getting more realistic,
so that the day when that limit becomes a problem is in sight,
even if it's not here yet. Hence, let's raise the limit.
Rather than just increase the values of INNER_VAR et al, this patch
adopts the approach of making them small negative values, so that
rangetables could theoretically become as long as INT_MAX.
The bulk of the patch is concerned with changing Var.varno and some
related variables from "Index" (unsigned int) to plain "int". This
is basically cosmetic, with little actual effect other than to help
debuggers print their values nicely. As such, I've only bothered
with changing places that could actually see INNER_VAR et al, which
the parser and most of the planner don't. We do have to be careful
in places that are performing less/greater comparisons on varnos,
but there are very few such places, other than the IS_SPECIAL_VARNO
macro itself.
A notable side effect of this patch is that while it used to be
possible to add INNER_VAR et al to a Bitmapset, that will now
draw an error. I don't see any likelihood that it wouldn't be a
bug to include these fake varnos in a bitmapset of real varnos,
so I think this is all to the good.
Although this touches outfuncs/readfuncs, I don't think a catversion
bump is required, since stored rules would never contain Vars
with these fake varnos.
Andrey Lepikhov and Tom Lane, after a suggestion by Peter Eisentraut
Discussion: https://postgr.es/m/43c7f2f5-1e27-27aa-8c65-c91859d15190@postgrespro.ru
Formerly, we sent signals for outgoing NOTIFY messages within
ProcessCompletedNotifies, which was also responsible for sending
relevant ones of those messages to our connected client. It therefore
had to run during the main-loop processing that occurs just before
going idle. This arrangement had two big disadvantages:
* Now that procedures allow intra-command COMMITs, it would be
useful to send NOTIFYs to other sessions immediately at COMMIT
(though, for reasons of wire-protocol stability, we still shouldn't
forward them to our client until end of command).
* Background processes such as replication workers would not send
NOTIFYs at all, since they never execute the client communication
loop. We've had requests to allow triggers running in replication
workers to send NOTIFYs, so that's a problem.
To fix these things, move transmission of outgoing NOTIFY signals
into AtCommit_Notify, where it will happen during CommitTransaction.
Also move the possible call of asyncQueueAdvanceTail there, to
ensure we don't bloat the async SLRU if a background worker sends
many NOTIFYs with no one listening.
We can also drop the call of asyncQueueReadAllNotifications,
allowing ProcessCompletedNotifies to go away entirely. That's
because commit 790026972 added a call of ProcessNotifyInterrupt
adjacent to PostgresMain's call of ProcessCompletedNotifies,
and that does its own call of asyncQueueReadAllNotifications,
meaning that we were uselessly doing two such calls (inside two
separate transactions) whenever inbound notify signals coincided
with an outbound notify. We need only set notifyInterruptPending
to ensure that ProcessNotifyInterrupt runs, and we're done.
The existing documentation suggests that custom background workers
should call ProcessCompletedNotifies if they want to send NOTIFY
messages. To avoid an ABI break in the back branches, reduce it
to an empty routine rather than removing it entirely. Removal
will occur in v15.
Although the problems mentioned above have existed for awhile,
I don't feel comfortable back-patching this any further than v13.
There was quite a bit of churn in adjacent code between 12 and 13.
At minimum we'd have to also backpatch 51004c717, and a good deal
of other adjustment would also be needed, so the benefit-to-risk
ratio doesn't look attractive.
Per bug #15293 from Michael Powers (and similar gripes from others).
Artur Zakirov and Tom Lane
Discussion: https://postgr.es/m/153243441449.1404.2274116228506175596@wrigleys.postgresql.org
It's possible for us to copy an AlternativeSubPlan expression node
into multiple places, for example the scan quals of several
partition children. Then it's possible that we choose a different
one of the alternatives as optimal in each place. Commit 41efb8340
failed to consider this scenario, so its attempt to remove "unused"
subplans could remove subplans that were still used elsewhere.
Fix by delaying the removal logic until we've examined all the
AlternativeSubPlans in a given query level. (This does assume that
AlternativeSubPlans couldn't get copied to other query levels, but
for the foreseeable future that's fine; cf qual_is_pushdown_safe.)
Per report from Rajkumar Raghuwanshi. Back-patch to v14
where the faulty logic came in.
Discussion: https://postgr.es/m/CAKcux6==O3NNZC3bZ2prRYv3cjm3_Zw1GfzmOjEVqYN4jub2+Q@mail.gmail.com
If an allocation failed within LLVM it is not safe to call back into LLVM as
LLVM is not generally safe against exceptions / stack-unwinding. Thus errors
while in LLVM code are promoted to FATAL. However llvm_shutdown() did call
back into LLVM even in such cases, while llvm_release_context() was careful
not to do so.
We cannot generally skip shutting down LLVM, as that can break profiling. But
it's OK to do so if there was an error from within LLVM.
Reported-By: Jelte Fennema <Jelte.Fennema@microsoft.com>
Author: Andres Freund <andres@anarazel.de>
Author: Justin Pryzby <pryzby@telsasoft.com>
Discussion: https://postgr.es/m/AM5PR83MB0178C52CCA0A8DEA0207DC14F7FF9@AM5PR83MB0178.EURPRD83.prod.outlook.com
Backpatch: 11-, where jit was introduced
Two functions, both named check_permissions(), used the same checks to
verify if a user had required privileges to work on replication slots.
This commit removes the duplication, and moves the function doing the
checks to slot.c to be centralized.
Author: Bharath Rupireddy
Reviewed-by: Nathan Bossart, Euler Taveira
Discussion: https://postgr.es/m/CALj2ACUPpVw1u7sQocFVWrSs0n10pt_G_4NPZKSxXK6cW1dErw@mail.gmail.com
The previous protocol expected a set of matching characters to check if
a message sent was the last one or not, that changed depending on the
destination wanted:
- 't' and 'f' tracked the last message of a log sent to stderr.
- 'T' and 'F' tracked the last message of a log sent to csvlog.
This could be extended with more characters when introducing new
destinations, but using a bitmask is much more elegant. This commit
changes the protocol so as a bitmask is used in the header of a log
chunk message sent to the syslogger, with the following options
available for now:
- log_destination as stderr.
- log_destination as csvlog.
- if a message is the last chunk of a message.
Sehrope found this issue in a patch set to introduce JSON as an option
for log_destination, but his patch made the size of the protocol header
larger. This commit keeps the same size as the original, and adapts the
protocol as wanted.
Thanks also to Andrew Dunstan and Greg Stark for the discussion.
Author: Michael Paquier, Sehrope Sarkuni
Discussion: https://postgr.es/m/CAH7T-aqswBM6JWe4pDehi1uOiufqe06DJWaU5=X7dDLyqUExHg@mail.gmail.com
This switches the default ACL to what the documentation has recommended
since CVE-2018-1058. Upgrades will carry forward any old ownership and
ACL. Sites that declined the 2018 recommendation should take a fresh
look. Recipes for commissioning a new database cluster from scratch may
need to create a schema, grant more privileges, etc. Out-of-tree test
suites may require such updates.
Reviewed by Peter Eisentraut.
Discussion: https://postgr.es/m/20201031163518.GB4039133@rfd.leadboat.com
The Value node struct is a weird construct. It is its own node type,
but most of the time, it actually has a node type of Integer, Float,
String, or BitString. As a consequence, the struct name and the node
type don't match most of the time, and so it has to be treated
specially a lot. There doesn't seem to be any value in the special
construct. There is very little code that wants to accept all Value
variants but nothing else (and even if it did, this doesn't provide
any convenient way to check it), and most code wants either just one
particular node type (usually String), or it accepts a broader set of
node types besides just Value.
This change removes the Value struct and node type and replaces them
by separate Integer, Float, String, and BitString node types that are
proper node types and structs of their own and behave mostly like
normal node types.
Also, this removes the T_Null node tag, which was previously also a
possible variant of Value but wasn't actually used outside of the
Value contained in A_Const. Replace that by an isnull field in
A_Const.
Reviewed-by: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/5ba6bc5b-3f95-04f2-2419-f8ddb4c046fb@enterprisedb.com
Robert Haas
Peter Geoghegan
Tom Lane
Amit Kapila
Jeff Davis
Michael Paquier
Noah Misch
Heikki Linnakangas
Andres Freund
Daniel Gustafsson
David Rowley
Alvaro Herrera
Peter Eisentraut
Alexander Korotkov