The project Git server hasn't supported cloning with the Git protocol
in a very long time, but the documentation never got the memo. Remove
the mention of using the Git protocol, and while there wrap a mention
of Git in <productname> tags.
Backpatch down to all supported versions.
Author: Daniel Gustafsson <daniel@yesql.se> Reported-by: Gurjeet Singh <gurjeet@singh.im> Reviewed-by: Nathan Bossart <nathandbossart@gmail.com> Reviewed-by: Jacob Champion <jacob.champion@enterprisedb.com> Reviewed-by: Gurjeet Singh <gurjeet@singh.im> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CABwTF4WMiMb-KT2NRcib5W0C8TQF6URMb+HK9a_=rnZnY8Q42w@mail.gmail.com
Backpatch-through: 13
Tom Lane [Thu, 23 Oct 2025 16:32:06 +0000 (12:32 -0400)]
Fix off-by-one Asserts in FreePageBtreeInsertInternal/Leaf.
These two functions expect there to be room to insert another item
in the FreePageBtree's array, but their assertions were too weak
to guarantee that. This has little practical effect granting that
the callers are not buggy, but it seems to be misleading late-model
Coverity into complaining about possible array overrun.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/799984.1761150474@sss.pgh.pa.us
Backpatch-through: 13
Tom Lane [Thu, 23 Oct 2025 15:47:46 +0000 (11:47 -0400)]
Fix resource leaks in PL/Python error reporting, redux.
Commit c6f7f11d8 intended to prevent leaking any PyObject reference
counts in edge cases (such as out-of-memory during string
construction), but actually it introduced a leak in the normal case.
Repeating an error-trapping operation often enough would lead to
session-lifespan memory bloat. The problem is that I failed to
think about the fact that PyObject_GetAttrString() increments the
refcount of the returned PyObject, so that simply walking down the
list of error frame objects causes all but the first one to have
their refcount incremented.
I experimented with several more-or-less-complex ways around that,
and eventually concluded that the right fix is simply to drop the
newly-obtained refcount as soon as we walk to the next frame
object in PLy_traceback. This sounds unsafe, but it's perfectly
okay because the caller holds a refcount on the first frame object
and each frame object holds a refcount on the next one; so the
current frame object can't disappear underneath us.
By the same token, we can simplify the caller's cleanup back to
simply dropping its refcount on the first object. Cleanup of
each frame object will lead in turn to the refcount of the next
one going to zero.
I also added a couple of comments explaining why PLy_elog_impl()
doesn't try to free the strings acquired from PLy_get_spi_error_data()
or PLy_get_error_data(). That's because I got here by looking at a
Coverity complaint about how those strings might get leaked. They
are not leaked, but in testing that I discovered this other leak.
Back-patch, as c6f7f11d8 was. It's a bit nervous-making to be
putting such a fix into v13, which is only a couple weeks from its
final release; but I can't see that leaving a recently-introduced
leak in place is a better idea.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/1203918.1761184159@sss.pgh.pa.us
Backpatch-through: 13
Fujii Masao [Thu, 23 Oct 2025 04:24:56 +0000 (13:24 +0900)]
Add comments explaining overflow entries in the replication lag tracker.
Commit 883a95646a8 introduced overflow entries in the replication lag tracker
to fix an issue where lag columns in pg_stat_replication could stall when
the replay LSN stopped advancing.
This commit adds comments clarifying the purpose and behavior of overflow
entries to improve code readability and understanding.
Since commit 883a95646a8 was recently applied and backpatched to all
supported branches, this follow-up commit is also backpatched accordingly.
David Rowley [Thu, 23 Oct 2025 00:12:49 +0000 (13:12 +1300)]
Fix incorrect zero extension of Datum in JIT tuple deform code
When JIT deformed tuples (controlled via the jit_tuple_deforming GUC),
types narrower than sizeof(Datum) would be zero-extended up to Datum
width. This wasn't the same as what fetch_att() does in the standard
tuple deforming code. Logically the values are the same when fetching
via the DatumGet*() marcos, but negative numbers are not the same in
binary form.
In the report, the problem was manifesting itself with:
ERROR: could not find memoization table entry
in a query which had a "Cache Mode: binary" Memoize node. However, it's
currently unclear what else is affected. Anything that uses
datum_image_eq() or datum_image_hash() on a Datum from a tuple deformed by
JIT could be affected, but it may not be limited to that.
The fix for this is simple: use signed extension instead of zero
extension.
Many thanks to Emmanuel Touzery for reporting this issue and providing
steps and backup which allowed the problem to easily be recreated.
Tom Lane [Wed, 22 Oct 2025 17:38:37 +0000 (13:38 -0400)]
Fix memory leaks in pg_combinebackup/reconstruct.c.
One code path forgot to free the separately-malloc'd filename
part of a struct rfile. Another place freed the filename but
forgot the struct rfile itself. These seem worth fixing because
with a large backup we could be dealing with many files.
Coverity found the bug in make_rfile(). I found the other one
by manual inspection.
Tom Lane [Wed, 22 Oct 2025 15:13:00 +0000 (11:13 -0400)]
Add commit 24f6c1bd4 to v17 .abi-compliance-history.
Per buildfarm. The breakage was discussed and deemed acceptable
in the patch thread, but it was not mentioned in the commit log,
so I missed spotting this one yesterday.
Discussion: https://postgr.es/m/787065.1761144050@sss.pgh.pa.us
Backpatch-through: 17 only
Fujii Masao [Wed, 22 Oct 2025 11:11:47 +0000 (20:11 +0900)]
Make invalid primary_slot_name follow standard GUC error reporting.
Previously, if primary_slot_name was set to an invalid slot name and
the configuration file was reloaded, both the postmaster and all other
backend processes reported a WARNING. With many processes running,
this could produce a flood of duplicate messages. The problem was that
the GUC check hook for primary_slot_name reported errors at WARNING
level via ereport().
This commit changes the check hook to use GUC_check_errdetail() and
GUC_check_errhint() for error reporting. As with other GUC parameters,
this causes non-postmaster processes to log the message at DEBUG3,
so by default, only the postmaster's message appears in the log file.
Fujii Masao [Wed, 22 Oct 2025 02:27:15 +0000 (11:27 +0900)]
Fix stalled lag columns in pg_stat_replication when replay LSN stops advancing.
Previously, when the replay LSN reported in feedback messages from a standby
stopped advancing, for example, due to a recovery conflict, the write_lag and
flush_lag columns in pg_stat_replication would initially update but then stop
progressing. This prevented users from correctly monitoring replication lag.
The problem occurred because when any LSN stopped updating, the lag tracker's
cyclic buffer became full (the write head reached the slowest read head).
In that state, the lag tracker could no longer compute round-trip lag values
correctly.
This commit fixes the issue by handling the slowest read entry (the one
causing the buffer to fill) as a separate overflow entry and freeing space
so the write and other read heads can continue advancing in the buffer.
As a result, write_lag and flush_lag now continue updating even if the reported
replay LSN remains stalled.
Nathan Bossart [Tue, 21 Oct 2025 21:37:29 +0000 (16:37 -0500)]
Add .abi-compliance-history to back-branches.
This file was previously added to v18 by commits a72f7d97be and 93fb76ca4e. Unlike the v18 version of the file, the back-branch
versions set the original baseline point to the most recent ABI
break documented in the git commit history. While we'd ordinarily
set it to something just before the .0 release, we're unlikely to
act upon ABI breaks in released minor versions, so it doesn't seem
worth the trouble to construct a comprehensive history.
David Rowley [Tue, 21 Oct 2025 07:47:10 +0000 (20:47 +1300)]
Fix BRIN 32-bit counter wrap issue with huge tables
A BlockNumber (32-bit) might not be large enough to add bo_pagesPerRange
to when the table contains close to 2^32 pages. At worst, this could
result in a cancellable infinite loop during the BRIN index scan with
power-of-2 pagesPerRange, and slow (inefficient) BRIN index scans and
scanning of unneeded heap blocks for non power-of-2 pagesPerRange.
Backpatch to all supported versions.
Author: sunil s <sunilfeb26@gmail.com> Reviewed-by: David Rowley <dgrowleyml@gmail.com> Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/CAOG6S4-tGksTQhVzJM19NzLYAHusXsK2HmADPZzGQcfZABsvpA@mail.gmail.com
Backpatch-through: 13
Michael Paquier [Mon, 20 Oct 2025 23:08:35 +0000 (08:08 +0900)]
Fix POSIX compliance in pgwin32_unsetenv() for "name" argument
pgwin32_unsetenv() (compatibility routine of unsetenv() on Windows)
lacks the input validation that its sibling pgwin32_setenv() has.
Without these checks, calling unsetenv() with incorrect names crashes on
WIN32. However, invalid names should be handled, failing on EINVAL.
This commit adds the same checks as setenv() to fail with EINVAL for a
"name" set to NULL, an empty string, or if '=' is included in the value,
per POSIX requirements.
Like 7ca37fb0406b, backpatch down to v14. pgwin32_unsetenv() is defined
on REL_13_STABLE, but with the branch going EOL soon and the lack of
setenv() there for WIN32, nothing is done for v13.
Author: Bryan Green <dbryan.green@gmail.com>
Discussion: https://postgr.es/m/b6a1e52b-d808-4df7-87f7-2ff48d15003e@gmail.com
Backpatch-through: 14
The revised logic in 001_ssltests.pl would fail if openssl
doesn't work or if Perl is a 32-bit build, because it had
already overwritten $serialno with something inappropriate
to use in the eventual match. We could go back to the
previous code layout, but it seems best to introduce a
separate variable for the output of openssl.
Per failure on buildfarm member mamba, which has a 32-bit Perl.
Tom Lane [Sun, 19 Oct 2025 18:36:58 +0000 (14:36 -0400)]
Don't rely on zlib's gzgetc() macro.
It emerges that zlib's configuration logic is not robust enough
to guarantee that the macro will have the same ideas about struct
field layout as the library itself does, leading to corruption of
zlib's state struct followed by unintelligible failure messages.
This hazard has existed for a long time, but we'd not noticed
for several reasons:
(1) We only use gzgetc() when trying to read a manually-compressed
TOC file within a directory-format dump, which is a rarely-used
scenario that we weren't even testing before 20ec99589.
(2) No corruption actually occurs unless sizeof(long) is different
from sizeof(off_t) and the platform is big-endian.
(3) Some platforms have already fixed the configuration instability,
at least sufficiently for their environments.
Despite (3), it seems foolish to assume that the problem isn't
going to be present in some environments for a long time to come.
Hence, avoid relying on this macro. We can just #undef it and
fall back on the underlying function of the same name.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/2122679.1760846783@sss.pgh.pa.us
Backpatch-through: 13
Álvaro Herrera [Sat, 18 Oct 2025 16:18:19 +0000 (18:18 +0200)]
Fix determination of not-null constraint "locality" for inherited columns
It is possible to have a non-inherited not-null constraint on an
inherited column, but we were failing to preserve such constraints
during pg_upgrade where the source is 17 or older, because of a bug in
the pg_dump query for it. Oversight in commit 14e87ffa5c54. Fix that
query. In passing, touch-up a bogus nearby comment introduced by the
same commit.
In version 17, make the regression tests leave a table in this
situation, so that this scenario is tested in the cross-version upgrade
tests of 18 and up.
Álvaro Herrera [Sat, 18 Oct 2025 15:50:10 +0000 (17:50 +0200)]
Fix pg_dump sorting of foreign key constraints
Apparently, commit 04bc2c42f765 failed to notice that DO_FK_CONSTRAINT
objects require identical handling as DO_CONSTRAINT ones, which causes
some pg_upgrade tests in debug builds to fail spuriously. Add that.
Nathan Bossart [Fri, 17 Oct 2025 16:36:50 +0000 (11:36 -0500)]
Fix privilege checks for pg_prewarm() on indexes.
pg_prewarm() currently checks for SELECT privileges on the target
relation. However, indexes do not have access rights of their own,
so a role may be denied permission to prewarm an index despite
having the SELECT privilege on its parent table. This commit fixes
this by locking the parent table before the index (to avoid
deadlocks) and checking for SELECT on the parent table. Note that
the code is largely borrowed from
amcheck_lock_relation_and_check().
An obvious downside of this change is the extra AccessShareLock on
the parent table during prewarming, but that isn't expected to
cause too much trouble in practice.
Author: Ayush Vatsa <ayushvatsa1810@gmail.com> Co-authored-by: Nathan Bossart <nathandbossart@gmail.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Jeff Davis <pgsql@j-davis.com>
Discussion: https://postgr.es/m/CACX%2BKaMz2ZoOojh0nQ6QNBYx8Ak1Dkoko%3DD4FSb80BYW%2Bo8CHQ%40mail.gmail.com
Backpatch-through: 13
Avoid warnings in tests when openssl binary isn't available
The SSL tests for pg_stat_ssl tries to exactly match the serial
from the certificate by extracting it with the openssl binary.
If that fails due to the binary not being available, a fallback
match is used, but the attempt to execute a missing binary adds
a warning to the output which can confuse readers for a failure
in the test. Fix by only attempting if the openssl binary was
found by autoconf/meson.
Backpatch down to v16 where commit c8e4030d1bdd made the test
use the OPENSSL variable from autoconf/meson instead of a hard-
coded value.
Author: Daniel Gustafsson <daniel@yesql.se> Reported-by: Christoph Berg <myon@debian.org>
Discussion: https://postgr.es/m/aNPSp1-RIAs3skZm@msg.df7cb.de
Backpatch-through: 16
Michael Paquier [Fri, 17 Oct 2025 04:06:11 +0000 (13:06 +0900)]
Fix matching check in recovery test 042_low_level_backup
042_low_level_backup compared the result of a query two times with a
comparison operator based on an integer, while the result should be
compared with a string.
The outcome of the tests is currently not impacted by this change.
However, it could be possible that the tests fail to detect future
issues if the query results become different, for some reason.
Álvaro Herrera [Thu, 16 Oct 2025 18:21:05 +0000 (20:21 +0200)]
Fix update-po for the PGXS case
The original formulation failed to take into account the fact that for
the PGXS case, the source dir is not $(top_srcdir), so it ended up not
doing anything. Handle it explicitly.
Etsuro Fujita [Wed, 15 Oct 2025 08:15:02 +0000 (17:15 +0900)]
Fix EvalPlanQual handling of foreign/custom joins in ExecScanFetch.
If inside an EPQ recheck, ExecScanFetch would run the recheck method
function for foreign/custom joins even if they aren't descendant nodes
in the EPQ recheck plan tree, which is problematic at least in the
foreign-join case, because such a foreign join isn't guaranteed to have
an alternative local-join plan required for running the recheck method
function; in the postgres_fdw case this could lead to a segmentation
fault or an assert failure in an assert-enabled build when running the
recheck method function.
Even if inside an EPQ recheck, any scan nodes that aren't descendant
ones in the EPQ recheck plan tree should be normally processed by using
the access method function; fix by modifying ExecScanFetch so that if
inside an EPQ recheck, it runs the recheck method function for
foreign/custom joins that are descendant nodes in the EPQ recheck plan
tree as before and runs the access method function for foreign/custom
joins that aren't.
This fix also adds to postgres_fdw an isolation test for an EPQ recheck
that caused issues stated above.
Michael Paquier [Mon, 13 Oct 2025 23:31:25 +0000 (08:31 +0900)]
Fix version number calculation for data folder flush in pg_combinebackup
The version number calculated by read_pg_version_file() is multiplied
once by 10000, to be able to do comparisons based on PG_VERSION_NUM or
equivalents with a minor version included. However, the version number
given sync_pgdata() was multiplied by 10000 a second time, leading to an
overestimated number.
This issue was harmless (still incorrect) as pg_combinebackup does not
support versions of Postgres older than v10, and sync_pgdata() only
includes a version check due to the rename of pg_xlog/ to pg_wal/. This
folder rename happened in the development cycle of v10. This would
become a problem if in the future sync_pgdata() is changed to have more
version-specific checks.
Oversight in dc212340058b, so backpatch down to v17.
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/aOil5d0y87ZM_wsZ@paquier.xyz
Backpatch-through: 17
Tom Lane [Mon, 13 Oct 2025 21:56:45 +0000 (17:56 -0400)]
Fix incorrect message-printing in win32security.c.
log_error() would probably fail completely if used, and would
certainly print garbage for anything that needed to be interpolated
into the message, because it was failing to use the correct printing
subroutine for a va_list argument.
This bug likely went undetected because the error cases this code
is used for are rarely exercised - they only occur when Windows
security API calls fail catastrophically (out of memory, security
subsystem corruption, etc).
The FRONTEND variant can be fixed just by calling vfprintf()
instead of fprintf(). However, there was no va_list variant
of write_stderr(), so create one by refactoring that function.
Following the usual naming convention for such things, call
it vwrite_stderr().
Author: Bryan Green <dbryan.green@gmail.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAF+pBj8goe4fRmZ0V3Cs6eyWzYLvK+HvFLYEYWG=TzaM+tWPnw@mail.gmail.com
Backpatch-through: 13
David Rowley [Mon, 13 Oct 2025 20:25:57 +0000 (09:25 +1300)]
Doc: clarify n_distinct_inherited setting
There was some confusion around how to adjust the n_distinct estimates
for partitioned tables. Here we try and clarify that
n_distinct_inherited needs to be adjusted rather than n_distinct.
Also fix some slightly misleading text which was talking about table
size rather than table rows, fix a grammatical error, and adjust some
text which indicated that ANALYZE was performing calculations based on
the n_distinct settings. Really it's the query planner that does this
and ANALYZE only stores the overridden n_distinct estimate value in
pg_statistic.
Author: David Rowley <dgrowleyml@gmail.com> Reviewed-by: David G. Johnston <david.g.johnston@gmail.com> Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Backpatch-through: 13
Discussion: https://postgr.es/m/CAApHDvrL7a-ZytM1SP8Uk9nEw9bR2CPzVb+uP+bcNj=_q-ZmVw@mail.gmail.com
Tom Lane [Mon, 13 Oct 2025 16:44:20 +0000 (12:44 -0400)]
Fix issue with reading zero bytes in Gzip_read.
pg_dump expects a read request of zero bytes to be a no-op; see for
example ReadStr(). Gzip_read got this wrong and falsely supposed
that the resulting gzret == 0 indicated an error. We could complicate
that error-checking logic some more, but it seems best to just fall
out immediately when passed size == 0.
This bug breaks the nominally-supported case of manually gzip'ing
the toc.dat file within a directory-style dump, so back-patch to v16
where this code came in. (Prior branches already have a short-circuit
for size == 0 before their only gzread call.)
Author: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/3515357.1760128017@sss.pgh.pa.us
Backpatch-through: 16
Tom Lane [Sat, 11 Oct 2025 20:33:55 +0000 (16:33 -0400)]
Restore test coverage of LZ4Stream_gets().
In commit a45c78e32 I removed the only regression test case that
reaches this function, because it turns out that we only use it
if reading an LZ4-compressed blobs.toc file in a directory dump,
and that is a state that has to be created manually. That seems
like a bad thing to not test, not so much for LZ4Stream_gets()
itself as because it means the squirrely eol_flag logic in
LZ4Stream_read_internal() is not tested.
The reason for the change was that I thought the lz4 program did not
have any way to perform compression without explicit specification
of the output file name. However, it turns out that the syntax
synopsis in its man page is a lie, and if you read enough of the
man page you find out that with "-m" it will do what's needful.
So restore the manual compression step in that test case.
Noted while testing some proposed changes in pg_dump's compression
logic.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/3515357.1760128017@sss.pgh.pa.us
Backpatch-through: 17
Álvaro Herrera [Sat, 11 Oct 2025 18:30:12 +0000 (20:30 +0200)]
Stop creating constraints during DETACH CONCURRENTLY
Commit 71f4c8c6f74b (which implemented DETACH CONCURRENTLY) added code
to create a separate table constraint when a table is detached
concurrently, identical to the partition constraint, on the theory that
such a constraint was needed in case the optimizer had constructed any
query plans that depended on the constraint being there. However, that
theory was apparently bogus because any such plans would be invalidated.
For hash partitioning, those constraints are problematic, because their
expressions reference the OID of the parent partitioned table, to which
the detached table is no longer related; this causes all sorts of
problems (such as inability of restoring a pg_dump of that table, and
the table no longer working properly if the partitioned table is later
dropped).
We'd like to get rid of all those constraints. In fact, for branch
master, do that -- no longer create any substitute constraints.
However, out of fear that some users might somehow depend on these
constraints for other partitioning strategies, for stable branches
(back to 14, which added DETACH CONCURRENTLY), only do it for hash
partitioning.
(If you repeatedly DETACH CONCURRENTLY and then ATTACH a partition, then
with this constraint addition you don't need to scan the table in the
ATTACH step, which presumably is good. But if users really valued this
feature, they would have requested that it worked for non-concurrent
DETACH also.)
Author: Haiyang Li <mohen.lhy@alibaba-inc.com> Reported-by: Fei Changhong <feichanghong@qq.com> Reported-by: Haiyang Li <mohen.lhy@alibaba-inc.com>
Backpatch-through: 14
Discussion: https://postgr.es/m/18371-7fef49f63de13f02@postgresql.org
Discussion: https://postgr.es/m/19070-781326347ade7c57@postgresql.org
Álvaro Herrera [Sat, 11 Oct 2025 14:39:22 +0000 (16:39 +0200)]
dbase_redo: Fix Valgrind-reported memory leak
Introduced by my (Álvaro's) commit 9e4f914b5eba, which was itself
backpatched to pg10, though only pg15 and up contain the problem
because of commit 9c08aea6a309.
This isn't a particularly significant leak, but given the fix is
trivial, we might as well backpatch to all branches where it applies, so
do that.
Author: Nathan Bossart <nathandbossart@gmail.com> Reported-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/x4odfdlrwvsjawscnqsqjpofvauxslw7b4oyvxgt5owoyf4ysn@heafjusodrz7
Peter Geoghegan [Fri, 10 Oct 2025 18:52:21 +0000 (14:52 -0400)]
Remove overzealous _bt_killitems assertion.
An assertion in _bt_killitems expected the scan's currPos state to
contain a valid LSN, saved from when currPos's page was initially read.
The assertion failed to account for the fact that even logged relations
can have leaf pages with an invalid LSN when built with wal_level set to
"minimal". Remove the faulty assertion.
Oversight in commit e6eed40e (though note that the assertion was
backpatched to stable branches before 18 by commit 7c319f54).
Author: Peter Geoghegan <pg@bowt.ie> Reported-By: Matthijs van der Vleuten <postgresql@zr40.nl>
Bug: #19082
Discussion: https://postgr.es/m/19082-628e62160dbbc1c1@postgresql.org
Backpatch-through: 13
Michael Paquier [Fri, 10 Oct 2025 00:24:50 +0000 (09:24 +0900)]
Remove state.tmp when failing to save a replication slot
An error happening while a slot data is saved on disk in
SaveSlotToPath() could cause a state.tmp file (temporary file holding
the slot state data, renamed to its permanent name at the end of the
function) to remain around after it has been created. This temporary
file is created with O_EXCL, meaning that if an existing state.tmp is
found, its creation would fail. This would prevent the slot data to be
saved, requiring a manual intervention to remove state.tmp before being
able to save again a slot. Possible scenarios where this temporary file
could remain on disk is for example a ENOSPC case (no disk space) while
writing, syncing or renaming it. The bug reports point to a write
failure as the principal cause of the problems.
Using O_TRUNC has been argued back in 2019 as a potential solution to
discard any temporary file that could exist. This solution was rejected
as O_EXCL can also act as a safety measure when saving the slot state,
crash recovery offering cleanup guarantees post-crash. This commit uses
the alternative approach that has been suggested by Andres Freund back
in 2019. When the temporary state file cannot be written, synced,
closed or renamed (note: not when created!), an unlink() is used to
remove the temporary state file while holding the in-progress I/O
LWLock, so as any follow-up attempts to save a slot's data would not
choke on an existing file that remained around because of a previous
failure.
This problem has been reported a few times across the years, going back
to 2019, but for some reason I have never come back to do something
about it and it has been forgotten. A recent report has reminded me
that this was still a problem.
Reported-by: Kevin K Biju <kevinkbiju@gmail.com> Reported-by: Sergei Kornilov <sk@zsrv.org> Reported-by: Grigory Smolkin <g.smolkin@postgrespro.ru>
Discussion: https://postgr.es/m/CAM45KeHa32soKL_G8Vk38CWvTBeOOXcsxAPAs7Jt7yPRf2mbVA@mail.gmail.com
Discussion: https://postgr.es/m/3559061693910326@qy4q4a6esb2lebnz.sas.yp-c.yandex.net
Discussion: https://postgr.es/m/08bbfab1-a61d-3750-fc18-4ab2c1aa7f09@postgrespro.ru
Backpatch-through: 13
Masahiko Sawada [Thu, 9 Oct 2025 17:59:31 +0000 (10:59 -0700)]
Fix access-to-already-freed-memory issue in pgoutput.
While pgoutput caches relation synchronization information in
RelationSyncCache that resides in CacheMemoryContext, each entry's
information (such as row filter expressions and column lists) is
stored in the entry's private memory context (entry_cxt in
RelationSyncEntry), which is a descendant memory context of the
decoding context. If a logical decoding invoked via SQL functions like
pg_logical_slot_get_binary_changes fails with an error, subsequent
logical decoding executions could access already-freed memory of the
entry's cache, resulting in a crash.
With this change, it's ensured that RelationSyncCache is cleaned up
even in error cases by using a memory context reset callback function.
Backpatch to 15, where entry_cxt was introduced for column filtering
and row filtering.
While the backbranches v13 and v14 have a similar issue where
RelationSyncCache persists even after an error when pgoutput is used
via SQL API, we decided not to backport this fix. This decision was
made because v13 is approaching its final minor release, and we won't
have an chance to fix any new issues that might arise. Additionally,
since using pgoutput via SQL API is not a common use case, the risk
outwights the benefit. If we receive bug reports, we can consider
backporting the fixes then.
Amit Langote [Thu, 9 Oct 2025 05:07:36 +0000 (01:07 -0400)]
Fix internal error from CollateExpr in SQL/JSON DEFAULT expressions
SQL/JSON functions such as JSON_VALUE could fail with "unrecognized
node type" errors when a DEFAULT clause contained an explicit COLLATE
expression. That happened because assign_collations_walker() could
invoke exprSetCollation() on a JsonBehavior expression whose DEFAULT
still contained a CollateExpr, which exprSetCollation() does not
handle.
For example:
SELECT JSON_VALUE('{"a":1}', '$.c' RETURNING text
DEFAULT 'A' COLLATE "C" ON EMPTY);
Fix by validating in transformJsonBehavior() that the DEFAULT
expression's collation matches the enclosing JSON expression’s
collation. In exprSetCollation(), replace the recursive call on the
JsonBehavior expression with an assertion that its collation already
matches the target, since the parser now enforces that condition.
Reported-by: Jian He <jian.universality@gmail.com>
Author: Jian He <jian.universality@gmail.com> Reviewed-by: Amit Langote <amitlangote09@gmail.com>
Discussion: https://postgr.es/m/CACJufxHVwYYSyiVQ6o+PsRX6zQ7rAFinh_fv1kCfTsT1xG4Zeg@mail.gmail.com
Backpatch-through: 17
Tom Lane [Sun, 5 Oct 2025 20:27:47 +0000 (16:27 -0400)]
Use SOCK_ERRNO[_SET] in fe-secure-gssapi.c.
On Windows, this code did not handle error conditions correctly at
all, since it looked at "errno" which is not used for socket-related
errors on that platform. This resulted, for example, in failure
to connect to a PostgreSQL server with GSSAPI enabled.
We have a convention for dealing with this within libpq, which is to
use SOCK_ERRNO and SOCK_ERRNO_SET rather than touching errno directly;
but the GSSAPI code is a relative latecomer and did not get that memo.
(The equivalent backend code continues to use errno, because the
backend does this differently. Maybe libpq's approach should be
rethought someday.)
Apparently nobody tries to build libpq with GSSAPI support on Windows,
or we'd have heard about this before, because it's been broken all
along. Back-patch to all supported branches.
Author: Ning Wu <ning94803@gmail.com> Co-authored-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAFGqpvg-pRw=cdsUpKYfwY6D3d-m9tw8WMcAEE7HHWfm-oYWvw@mail.gmail.com
Backpatch-through: 13
John Naylor [Fri, 3 Oct 2025 09:06:03 +0000 (16:06 +0700)]
Fix reuse-after-free hazard in dead_items_reset
In similar vein to commit ccc8194e427, a reset instance of a shared
memory TID store happened to occupy the same private memory as the old
one for the entry point, since the chunk freed after the last round
of index vacuuming was put on the context's freelist. The failure
to update the vacrel->dead_items pointer was evident by nudging the
system to allocate memory in a different area. This was not discovered
at the time of the earlier commit since our regression tests didn't
cover multiple index passes with parallel vacuum.
Backpatch to v17, when TidStore came in.
Author: Kevin Oommen Anish <kevin.o@zohocorp.com> Reviewed-by: Richard Guo <guofenglinux@gmail.com> Tested-by: Richard Guo <guofenglinux@gmail.com>
Discussion: https://postgr.es/m/199a07cbdfc.7a1c4aac25838.1675074408277594551%40zohocorp.com
Backpatch-through: 17
Michael Paquier [Fri, 3 Oct 2025 05:04:01 +0000 (14:04 +0900)]
pgbench: Fail cleanly when finding a COPY result state
Currently, pgbench aborts when a COPY response is received in
readCommandResponse(). However, as PQgetResult() returns an empty
result when there is no asynchronous result, through getCopyResult(),
the logic done at the end of readCommandResponse() for the error path
leads to an infinite loop.
This commit forcefully exits the COPY state with PQendcopy() before
moving to the error handler when fiding a COPY state, avoiding the
infinite loop. The COPY protocol is not supported by pgbench anyway, as
an error is assumed in this case, so giving up is better than having the
tool be stuck forever. pgbench was interruptible in this state.
A TAP test is added to check that an error happens if trying to use
COPY.
Michael Paquier [Thu, 2 Oct 2025 02:09:12 +0000 (11:09 +0900)]
pgstattuple: Improve reports generated for indexes (hash, gist, btree)
pgstattuple checks the state of the pages retrieved for gist and hash
using some check functions from each index AM, respectively
gistcheckpage() and _hash_checkpage(). When these are called, they
would fail when bumping on data that is found as incorrect (like opaque
area size not matching, or empty pages), contrary to btree that simply
discards these cases and continues to aggregate data.
Zero pages can happen after a crash, with these AMs being able to do an
internal cleanup when these are seen. Also, sporadic failures are
annoying when doing for example a large-scale diagnostic query based on
pgstattuple with a join of pg_class, as it forces one to use tricks like
quals to discard hash or gist indexes, or use a PL wrapper able to catch
errors.
This commit changes the reports generated for btree, gist and hash to
be more user-friendly;
- When seeing an empty page, report it as free space. This new rule
applies to gist and hash, and already applied to btree.
- For btree, a check based on the size of BTPageOpaqueData is added.
- For gist indexes, gistcheckpage() is not called anymore, replaced by a
check based on the size of GISTPageOpaqueData.
- For hash indexes, instead of _hash_getbuf_with_strategy(), use a
direct call to ReadBufferExtended(), coupled with a check based on
HashPageOpaqueData. The opaque area size check was already used.
- Pages that do not match these criterias are discarded from the stats
reports generated.
There have been a couple of bug reports over the years that complained
about the current behavior for hash and gist, as being not that useful,
with nothing being done about it. Hence this change is backpatched down
to v13.
Jacob Champion [Wed, 1 Oct 2025 16:25:21 +0000 (09:25 -0700)]
test_json_parser: Speed up 002_inline.pl
Some macOS machines are having trouble with 002_inline, which executes
the JSON parser test executables hundreds of times in a nested loop.
Both developer machines and buildfarm critters have shown excessive test
durations, upwards of 20 seconds.
Push the innermost loop of 002_inline, which iterates through differing
chunk sizes, down into the test executable. (I'd eventually like to push
all of the JSON unit tests down into C, but this is an easy win in the
short term.) Testers have reported a speedup between 4-9x.
Reported-by: Robert Haas <robertmhaas@gmail.com> Suggested-by: Andres Freund <andres@anarazel.de> Tested-by: Andrew Dunstan <andrew@dunslane.net> Tested-by: Tom Lane <tgl@sss.pgh.pa.us> Tested-by: Robert Haas <robertmhaas@gmail.com>
Discussion: https://postgr.es/m/CA%2BTgmobKoG%2BgKzH9qB7uE4MFo-z1hn7UngqAe9b0UqNbn3_XGQ%40mail.gmail.com
Backpatch-through: 17
pgbench: Fix error reporting in readCommandResponse().
pgbench uses readCommandResponse() to process server responses.
When readCommandResponse() encounters an error during a call to
PQgetResult() to fetch the current result, it attempts to report it
with an additional error message from PQerrorMessage(). However,
previously, this extra error message could be lost or become incorrect.
The cause was that after fetching the current result (and detecting
an error), readCommandResponse() called PQgetResult() again to
peek at the next result. This second call could overwrite the libpq
connection's error message before the original error was reported,
causing the error message retrieved from PQerrorMessage() to be
lost or overwritten.
This commit fixes the issue by updating readCommandResponse()
to use PQresultErrorMessage() instead of PQerrorMessage()
to retrieve the error message generated when the PQgetResult()
for the current result causes an error, ensuring the correct message
is reported.
Neighbor get_statistics_object_oid() ignores objects in pg_temp, as has
been the standard for non-relation, non-type namespace searches since
CVE-2007-2138. Hence, most operations that name a statistics object
correctly decline to map an unqualified name to a statistics object in
pg_temp. StatisticsObjIsVisibleExt() did not. Consequently,
pg_statistics_obj_is_visible() wrongly returned true for such objects,
psql \dX wrongly listed them, and getObjectDescription()-based ereport()
and pg_describe_object() wrongly omitted namespace qualification. Any
malfunction beyond that would depend on how a human or application acts
on those wrong indications. Commit d99d58cdc8c0b5b50ee92995e8575c100b1a458a introduced this. Back-patch to
v13 (all supported versions).
Tom Lane [Sat, 27 Sep 2025 18:29:41 +0000 (14:29 -0400)]
Fix missed copying of groupDistinct in transformPLAssignStmt.
Because we failed to do this, DISTINCT in GROUP BY DISTINCT would be
ignored in PL/pgSQL assignment statements. It's not surprising that
no one noticed, since such statements will throw an error if the query
produces more than one row. That eliminates most scenarios where
advanced forms of GROUP BY could be useful, and indeed makes it hard
even to find a simple test case. Nonetheless it's wrong.
This is directly the fault of be45be9c3 which added the groupDistinct
field, but I think much of the blame has to fall on c9d529848, in
which I incautiously supposed that we'd manage to keep two copies of
a big chunk of parse-analysis logic in sync. As a follow-up, I plan
to refactor so that there's only one copy. But that seems useful
only in master, so let's use this one-line fix for the back branches.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/31027.1758919078@sss.pgh.pa.us
Backpatch-through: 14
pgbench: Fix assertion failure with retriable errors in pipeline mode.
When running pgbench with --verbose-errors option and a custom script that
triggered retriable errors (e.g., serialization errors) in pipeline mode,
an assertion failure could occur:
Assertion failed: (sql_script[st->use_file].commands[st->command]->type == 1), function commandError, file pgbench.c, line 3062.
The failure happened because pgbench assumed these errors would only occur
during SQL commands, but in pipeline mode they can also happen during
\endpipeline meta command.
This commit fixes the assertion failure by adjusting the assertion check to
allow such errors during either SQL commands or \endpipeline.
Backpatch to v15, where the assertion check was introduced.
Tom Lane [Thu, 25 Sep 2025 17:29:02 +0000 (13:29 -0400)]
Add minimal sleep to stats isolation test functions.
The functions test_stat_func() and test_stat_func2() had empty
function bodies, so that they took very little time to run. This made
it possible that on machines with relatively low timer resolution the
functions could return before the clock advanced, making the test fail
(as seen on buildfarm members fruitcrow and hamerkop).
To avoid that, pg_sleep for 10us during the functions. As far as we
can tell, all current hardware has clock resolution much less than
that. (The current implementation of pg_sleep will round it up to
1ms anyway, but someday that might get improved.)
Author: Michael Banck <mbanck@gmx.net> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/68d413a3.a70a0220.24c74c.8be9@mx.google.com
Backpatch-through: 15
When defining an injection point there is no need to wrap the definition
with USE_INJECTION_POINT guards, the INJECTION_POINT macro is available
in all builds. Remove to make the code consistent.
Author: Hayato Kuroda <kuroda.hayato@fujitsu.com> Reviewed-by: Michael Paquier <michael@paquier.xyz> Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://postgr.es/m/OSCPR01MB14966C8015DEB05ABEF2CE077F51FA@OSCPR01MB14966.jpnprd01.prod.outlook.com
Backpatch-through: 17
Amit Kapila [Wed, 24 Sep 2025 03:49:02 +0000 (03:49 +0000)]
Fix LOCK_TIMEOUT handling during parallel apply.
Previously, the parallel apply worker used SIGINT to receive a graceful
shutdown signal from the leader apply worker. However, SIGINT is also used
by the LOCK_TIMEOUT handler to trigger a query-cancel interrupt. This
overlap caused the parallel apply worker to miss LOCK_TIMEOUT signals,
leading to incorrect behavior during lock wait/contention.
This patch resolves the conflict by switching the graceful shutdown signal
from SIGINT to SIGUSR2.
Reported-by: Zane Duffield <duffieldzane@gmail.com> Diagnosed-by: Zhijie Hou <houzj.fnst@fujitsu.com>
Author: Hayato Kuroda <kuroda.hayato@fujitsu.com> Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Backpatch-through: 16, where it was introduced
Discussion: https://postgr.es/m/CACMiCkXyC4au74kvE2g6Y=mCEF8X6r-Ne_ty4r7qWkUjRE4+oQ@mail.gmail.com
Michael Paquier [Sun, 21 Sep 2025 23:03:28 +0000 (08:03 +0900)]
Fix meson build with -Duuid=ossp when using version older than 0.60
The package for the UUID library may be named "uuid" or "ossp-uuid", and
meson.build has been using a single call of dependency() with multiple
names, something only supported since meson 0.60.0.
The minimum version of meson supported by Postgres is 0.57.2 on HEAD,
since f039c2244110, and 0.54 on stable branches down to 16.
Author: Oreo Yang <oreo.yang@hotmail.com> Reviewed-by: Nazir Bilal Yavuz <byavuz81@gmail.com>
Discussion: https://postgr.es/m/OS3P301MB01656E6F91539770682B1E77E711A@OS3P301MB0165.JPNP301.PROD.OUTLOOK.COM
Backpatch-through: 16
pg_restore: Fix security label handling with --no-publications/subscriptions.
Previously, pg_restore did not skip security labels on publications or
subscriptions even when --no-publications or --no-subscriptions was specified.
As a result, it could issue SECURITY LABEL commands for objects that were
never created, causing those commands to fail.
This commit fixes the issue by ensuring that security labels on publications
and subscriptions are also skipped when the corresponding options are used.
Tom Lane [Wed, 17 Sep 2025 20:32:57 +0000 (16:32 -0400)]
Calculate agglevelsup correctly when Aggref contains a CTE.
If an aggregate function call contains a sub-select that has
an RTE referencing a CTE outside the aggregate, we must treat
that reference like a Var referencing the CTE's query level
for purposes of determining the aggregate's level. Otherwise
we might reach the nonsensical conclusion that the aggregate
should be evaluated at some query level higher than the CTE,
ending in a planner error or a broken plan tree that causes
executor failures.
Bug: #19055 Reported-by: BugForge <dllggyx@outlook.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/19055-6970cfa8556a394d@postgresql.org
Backpatch-through: 13
David Rowley [Wed, 17 Sep 2025 00:20:19 +0000 (12:20 +1200)]
Add missing EPQ recheck for TID Range Scan
The EvalPlanQual recheck for TID Range Scan wasn't rechecking the TID qual
still passed after following update chains. This could result in tuples
being updated or deleted by plans using TID Range Scans where the ctid of
the new (updated) tuple no longer matches the clause of the scan. This
isn't desired behavior, and isn't consistent with what would happen if the
chosen plan had used an Index or Seq Scan, and that could lead to hard to
predict behavior for scans that contain TID quals and other quals as the
planner has freedom to choose TID Range or some other non-TID scan method
for such queries, and the chosen plan could change at any moment.
Here we fix this by properly implementing the recheck function for TID
Range Scans.
Backpatch to 14, where TID Range Scans were added
Reported-by: Sophie Alpert <pg@sophiebits.com>
Author: Sophie Alpert <pg@sophiebits.com>
Author: David Rowley <dgrowleyml@gmail.com> Reviewed-by: David Rowley <dgrowleyml@gmail.com> Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/4a6268ff-3340-453a-9bf5-c98d51a6f729@app.fastmail.com
Backpatch-through: 14
David Rowley [Tue, 16 Sep 2025 23:49:49 +0000 (11:49 +1200)]
Add missing EPQ recheck for TID Scan
The EvalPlanQual recheck for TID Scan wasn't rechecking the TID qual
still passed after following update chains. This could result in tuples
being updated or deleted by plans using TID Scans where the ctid of the
new (updated) tuple no longer matches the clause of the scan. This isn't
desired behavior, and isn't consistent with what would happen if the
chosen plan had used an Index or Seq Scan, and that could lead to hard to
predict behavior for scans that contain TID quals and other quals as the
planner has freedom to choose TID or some other scan method for such
queries, and the chosen plan could change at any moment.
Here we fix this by properly implementing the recheck function for TID
Scans.
Backpatch to 13, oldest supported version
Reported-by: Sophie Alpert <pg@sophiebits.com>
Author: Sophie Alpert <pg@sophiebits.com>
Author: David Rowley <dgrowleyml@gmail.com> Reviewed-by: David Rowley <dgrowleyml@gmail.com> Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/4a6268ff-3340-453a-9bf5-c98d51a6f729@app.fastmail.com
Backpatch-through: 13
Fix pg_dump COMMENT dependency for separate domain constraints.
The COMMENT should depend on the separately-dumped constraint, not the
domain. Sufficient restore parallelism might fail the COMMENT command
by issuing it before the constraint exists. Back-patch to v13, like
commit 0858f0f96ebb891c8960994f023ed5a17b758a38.
Tom Lane [Tue, 16 Sep 2025 14:09:49 +0000 (10:09 -0400)]
Add regression expected-files for older OpenSSL in FIPS mode.
In our previous discussions around making our regression tests
pass in FIPS mode, we concluded that we didn't need to support
the different error message wording observed with pre-3.0 OpenSSL.
However there are still a few LTS distributions soldiering along
with such versions, and now we have some in the buildfarm.
So let's add the variant expected-files needed to make them happy.
This commit only covers the core regression tests. Previous
discussion suggested that we might need some adjustments in
contrib as well, but it's not totally clear to me what those
would be. Rather than work it out from first principles,
I'll wait to see what the buildfarm shows.
Back-patch to v17 which is the oldest branch that claims
to support this case.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/443709.1757876535@sss.pgh.pa.us
Backpatch-through: 17
Richard Guo [Tue, 16 Sep 2025 09:42:20 +0000 (18:42 +0900)]
Treat JsonConstructorExpr as non-strict
JsonConstructorExpr can produce non-NULL output with a NULL input, so
it should be treated as a non-strict construct. Failing to do so can
lead to incorrect query behavior.
For example, in the reported case, when pulling up a subquery that is
under an outer join, if the subquery's target list contains a
JsonConstructorExpr that uses subquery variables and it is mistakenly
treated as strict, it will be pulled up without being wrapped in a
PlaceHolderVar. As a result, the expression will be evaluated at the
wrong place and will not be forced to null when the outer join should
do so.
Back-patch to v16 where JsonConstructorExpr was introduced.
Bug: #19046 Reported-by: Runyuan He <runyuan@berkeley.edu>
Author: Tender Wang <tndrwang@gmail.com> Co-authored-by: Richard Guo <guofenglinux@gmail.com>
Discussion: https://postgr.es/m/19046-765b6602b0a8cfdf@postgresql.org
Backpatch-through: 16
pg_dump: Fix dumping of security labels on subscriptions and event triggers.
Previously, pg_dump incorrectly queried pg_seclabel to retrieve security labels
for subscriptions, which are stored in pg_shseclabel as they are global objects.
This could result in security labels for subscriptions not being dumped.
This commit fixes the issue by updating pg_dump to query the pg_seclabels view,
which aggregates entries from both pg_seclabel and pg_shseclabel.
While querying pg_shseclabel directly for subscriptions was an alternative,
using pg_seclabels is simpler and sufficient.
In addition, pg_dump is updated to dump security labels on event triggers,
which were previously omitted.
pg_restore: Fix comment handling with --no-publications / --no-subscriptions.
Previously, pg_restore did not skip comments on publications or subscriptions
even when --no-publications or --no-subscriptions was specified. As a result,
it could issue COMMENT commands for objects that were never created,
causing those commands to fail.
This commit fixes the issue by ensuring that comments on publications and
subscriptions are also skipped when the corresponding options are used.
The previous change (commit f225473cbae) was still not on target,
because it talked about relation kinds, which are not what is being
checked here. Provide a more accurate message.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CACJufxEZ48toGH0Em_6vdsT57Y3L8pLF=DZCQ_gCii6=C3MeXw@mail.gmail.com
Tom Lane [Sat, 13 Sep 2025 20:55:51 +0000 (16:55 -0400)]
Amend recent fix for SIMILAR TO regex conversion.
Commit e3ffc3e91 fixed the translation of character classes in
SIMILAR TO regular expressions. Unfortunately the fix broke a corner
case: if there is an escape character right after the opening bracket
(for example in "[\q]"), a closing bracket right after the escape
sequence would not be seen as closing the character class.
There were two more oversights: a backslash or a nested opening bracket
right at the beginning of a character class should remove the special
meaning from any following caret or closing bracket.
This bug suggests that this code needs to be more readable, so also
rename the variables "charclass_depth" and "charclass_start" to
something more meaningful, rewrite an "if" cascade to be more
consistent, and improve the commentary.
Reported-by: Dominique Devienne <ddevienne@gmail.com> Reported-by: Stephan Springl <springl-psql@bfw-online.de>
Author: Laurenz Albe <laurenz.albe@cybertec.at> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAFCRh-8NwJd0jq6P=R3qhHyqU7hw0BTor3W0SvUcii24et+zAw@mail.gmail.com
Backpatch-through: 13
Tom Lane [Fri, 12 Sep 2025 21:43:15 +0000 (17:43 -0400)]
Fix oversights in pg_event_trigger_dropped_objects() fixes.
Commit a0b99fc12 caused pg_event_trigger_dropped_objects()
to not fill the object_name field for schemas, which it
should have; and caused it to fill the object_name field
for default values, which it should not have.
In addition, triggers and RLS policies really should behave
the same way as we're making column defaults do; that is,
they should have is_temporary = true if they belong to a
temporary table.
Fix those things, and upgrade event_trigger.sql's woefully
inadequate test coverage of these secondary output columns.
As before, back-patch only to v15.
Reported-by: Sergey Shinderuk <s.shinderuk@postgrespro.ru>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/bd7b4651-1c26-4d30-832b-f942fabcb145@postgrespro.ru
Backpatch-through: 15
Tom Lane [Thu, 11 Sep 2025 21:11:54 +0000 (17:11 -0400)]
Report the correct is_temporary flag for column defaults.
pg_event_trigger_dropped_objects() would report a column default
object with is_temporary = false, even if it belongs to a
temporary table. This seems clearly wrong, so adjust it to
report the table's temp-ness.
While here, refactor EventTriggerSQLDropAddObject to make its
handling of namespace objects less messy and avoid duplication
of the schema-lookup code. And add some explicit test coverage
of dropped-object reports for dependencies of temp tables.
Back-patch to v15. The bug exists further back, but the
GetAttrDefaultColumnAddress function this patch depends on does not,
and it doesn't seem worth adjusting it to cope with the older code.
Author: Antoine Violin <violin.antuan@gmail.com> Co-authored-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAFjUV9x3-hv0gihf+CtUc-1it0hh7Skp9iYFhMS7FJjtAeAptA@mail.gmail.com
Backpatch-through: 15
Peter Eisentraut [Thu, 11 Sep 2025 09:55:29 +0000 (11:55 +0200)]
Remove stray semicolon at global scope
The Sun Studio compiler complains about an empty declaration here.
Note for future historians: This does not mean that this compiler is
still of current interest for anyone using PostgreSQL. But we can let
this small fix be its parting gift.
Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/a0f817ee-fb86-483a-8a14-b6f7f5991b6e%40eisentraut.org
Michael Paquier [Thu, 11 Sep 2025 08:17:26 +0000 (17:17 +0900)]
Fix description of WAL record blocks in hash_xlog.h
hash_xlog.h included descriptions for the blocks used in WAL records
that were was not completely consistent with how the records are
generated, with one block missing for SQUEEZE_PAGE, and inconsistent
descriptions used for block 0 in VACUUM_ONE_PAGE and MOVE_PAGE_CONTENTS.
This information was incorrect since c11453ce0aea, cross-checking the
logic for the record generation.
Michael Paquier [Thu, 11 Sep 2025 01:15:39 +0000 (10:15 +0900)]
Fix incorrect file reference in guc.h
GucSource_Names was documented as being in guc.c, but since 0a20ff54f5e6
it is located in guc_tables.c. The reference to the location of
GucSource_Names is important, as GucSource needs to be kept in sync with
GucSource_Names.
Author: David G. Johnston <david.g.johnston@gmail.com>
Discussion: https://postgr.es/m/CAKFQuwYPgAHWPYjPzK7iXzhSZ6MKR8w20_Nz7ZXpOvx=kZbs7A@mail.gmail.com
Backpatch-through: 16
Tom Lane [Wed, 10 Sep 2025 20:05:03 +0000 (16:05 -0400)]
Fix memory leakage in nodeSubplan.c.
If the hash functions used for hashing tuples leaked any memory,
we failed to clean that up, resulting in query-lifespan memory
leakage in queries using hashed subplans. One way that could
happen is if the values being hashed require de-toasting, since
most of our hash functions don't trouble to clean up de-toasted
inputs.
Prior to commit bf6c614a2, this leakage was largely masked
because TupleHashTableMatch would reset hashtable->tempcxt
(via execTuplesMatch). But it doesn't do that anymore, and
that's not really the right place for this anyway: doing it
there could reset the tempcxt many times per hash lookup,
or not at all. Instead put reset calls into ExecHashSubPlan
and buildSubPlanHash. Along the way to that, rearrange
ExecHashSubPlan so that there's just one place to call
MemoryContextReset instead of several.
This amounts to accepting the de-facto API spec that the caller
of the TupleHashTable routines is responsible for resetting the
tempcxt adequately often. Although the other callers seem to
get this right, it was not documented anywhere, so add a comment
about it.
Bug: #19040 Reported-by: Haiyang Li <mohen.lhy@alibaba-inc.com>
Author: Haiyang Li <mohen.lhy@alibaba-inc.com> Reviewed-by: Fei Changhong <feichanghong@qq.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/19040-c9b6073ef814f48c@postgresql.org
Backpatch-through: 13
Michael Paquier [Tue, 9 Sep 2025 22:23:24 +0000 (07:23 +0900)]
Fix leak with SMgrRelations in startup process
The startup process does not process shared invalidation messages, only
sending them, and never calls AtEOXact_SMgr() which clean up any
unpinned SMgrRelations. Hence, it is never able to free SMgrRelations
on a periodic basis, bloating its hashtable over time.
Like the checkpointer and the bgwriter, this commit takes a conservative
approach by freeing periodically SMgrRelations when replaying a
checkpoint record, either online or shutdown, so as the startup process
has a way to perform a periodic cleanup.
Issue caused by 21d9c3ee4ef7, so backpatch down to v17.
This section claims that each backend executes the
shmem_startup_hook shortly after attaching to shared memory, which
is true for EXEC_BACKEND builds, but not for others. This commit
adds this important detail.
Michael Paquier [Mon, 8 Sep 2025 06:52:51 +0000 (15:52 +0900)]
Fix corruption of pgstats shared hashtable due to OOM failures
A new pgstats entry is created as a two-step process:
- The entry is looked at in the shared hashtable of pgstats, and is
inserted if not found.
- When not found and inserted, its fields are then initialized. This
part include a DSA chunk allocation for the stats data of the new entry.
As currently coded, if the DSA chunk allocation fails due to an
out-of-memory failure, an ERROR is generated, leaving in the pgstats
shared hashtable an inconsistent entry due to the first step, as the
entry has already been inserted in the hashtable. These broken entries
can then be found by other backends, crashing them.
There are only two callers of pgstat_init_entry(), when loading the
pgstats file at startup and when creating a new pgstats entry. This
commit changes pgstat_init_entry() so as we use dsa_allocate_extended()
with DSA_ALLOC_NO_OOM, making it return NULL on allocation failure
instead of failing. This way, a backend failing an entry creation can
take appropriate cleanup actions in the shared hashtable before throwing
an error. Currently, this means removing the entry from the shared
hashtable before throwing the error for the allocation failure.
Out-of-memory errors unlikely happen in the wild, and we do not bother
with back-patches when these are fixed, usually. However, the problem
dealt with here is a degree worse as it breaks the shared memory state
of pgstats, impacting other processes that may look at an inconsistent
entry that a different process has failed to create.
Author: Mikhail Kot <mikhail.kot@databricks.com>
Discussion: https://postgr.es/m/CAAi9E7jELo5_-sBENftnc2E8XhW2PKZJWfTC3i2y-GMQd2bcqQ@mail.gmail.com
Backpatch-through: 15
Dean Rasheed [Fri, 5 Sep 2025 07:22:38 +0000 (08:22 +0100)]
Fix concurrent update issue with MERGE.
When executing a MERGE UPDATE action, if there is more than one
concurrent update of the target row, the lock-and-retry code would
sometimes incorrectly identify the latest version of the target tuple,
leading to incorrect results.
This was caused by using the ctid field from the TM_FailureData
returned by table_tuple_lock() in a case where the result was TM_Ok,
which is unsafe because the TM_FailureData struct is not guaranteed to
be fully populated in that case. Instead, it should use the tupleid
passed to (and updated by) table_tuple_lock().
To reduce the chances of similar errors in the future, improve the
commentary for table_tuple_lock() and TM_FailureData to make it
clearer that table_tuple_lock() updates the tid passed to it, and most
fields of TM_FailureData should not be relied on in non-failure cases.
An exception to this is the "traversed" field, which is set in both
success and failure cases.
Reported-by: Dmitry <dsy.075@yandex.ru>
Author: Yugo Nagata <nagata@sraoss.co.jp> Reviewed-by: Dean Rasheed <dean.a.rasheed@gmail.com> Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/1570d30e-2b95-4239-b9c3-f7bf2f2f8556@yandex.ru
Backpatch-through: 15
Michael Paquier [Fri, 5 Sep 2025 05:10:26 +0000 (14:10 +0900)]
Fix outdated comments in slru.c
SlruRecentlyUsed() is an inline function since 53c2a97a9266, not a
macro. The description of long_segment_names was missing at the top of
SimpleLruInit(), part forgotten in 4ed8f0913bfd.
Dean Rasheed [Thu, 4 Sep 2025 10:48:02 +0000 (11:48 +0100)]
Fix replica identity check for MERGE.
When executing a MERGE, check that the target relation supports all
actions mentioned in the MERGE command. Specifically, check that it
has a REPLICA IDENTITY if it publishes updates or deletes and the
MERGE command contains update or delete actions. Failing to do this
can silently break replication.
Author: Zhijie Hou <houzj.fnst@fujitsu.com> Reviewed-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> Reviewed-by: Dean Rasheed <dean.a.rasheed@gmail.com> Tested-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/OS3PR01MB57180C87E43A679A730482DF94B62@OS3PR01MB5718.jpnprd01.prod.outlook.com
Backpatch-through: 15
Dean Rasheed [Thu, 4 Sep 2025 10:33:00 +0000 (11:33 +0100)]
Fix replica identity check for INSERT ON CONFLICT DO UPDATE.
If an INSERT has an ON CONFLICT DO UPDATE clause, the executor must
check that the target relation supports UPDATE as well as INSERT. In
particular, it must check that the target relation has a REPLICA
IDENTITY if it publishes updates. Formerly, it was not doing this
check, which could lead to silently breaking replication.
Fix by adding such a check to CheckValidResultRel(), which requires
adding a new onConflictAction argument. In back-branches, preserve ABI
compatibility by introducing a wrapper function with the original
signature.
Author: Zhijie Hou <houzj.fnst@fujitsu.com> Reviewed-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> Reviewed-by: Dean Rasheed <dean.a.rasheed@gmail.com> Tested-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/OS3PR01MB57180C87E43A679A730482DF94B62@OS3PR01MB5718.jpnprd01.prod.outlook.com
Backpatch-through: 13
Richard Guo [Wed, 3 Sep 2025 07:00:38 +0000 (16:00 +0900)]
Fix planner error when estimating SubPlan cost
SubPlan nodes are typically built very early, before any RelOptInfos
have been constructed for the parent query level. As a result, the
simple_rel_array in the parent root has not yet been initialized.
Currently, during cost estimation of a SubPlan's testexpr, we may call
examine_variable() to look up statistical data about the expressions.
This can lead to "no relation entry for relid" errors.
To fix, pass root as NULL to cost_qual_eval() in cost_subplan(), since
the root does not yet contain enough information to safely consult
statistics.
One exception is SubPlan nodes built for the initplans of MIN/MAX
aggregates from indexes. In this case, having a NULL root is safe
because testexpr will be NULL. Additionally, an initplan will by
definition not consult anything from the parent plan.
Backpatch to all supported branches. Although the reported call path
that triggers this error is not reachable prior to v17, there's no
guarantee that other code paths -- especially in extensions -- could
not encounter the same issue when cost_qual_eval() is called with a
root that lacks a valid simple_rel_array. The test case is not
included in pre-v17 branches though.
Bug: #19037 Reported-by: Alexander Lakhin <exclusion@gmail.com> Diagnosed-by: Tom Lane <tgl@sss.pgh.pa.us>
Author: Richard Guo <guofenglinux@gmail.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/19037-3d1c7bb553c7ce84@postgresql.org
Backpatch-through: 13
Michael Paquier [Wed, 3 Sep 2025 03:54:29 +0000 (12:54 +0900)]
libpq: Fix PQtrace() format for non-printable characters
PQtrace() was generating its output for non-printable characters without
casting the characters printed with unsigned char, leading to some extra
"\xffffff" generated in the output due to the fact that char may be
signed.
Oversights introduced by commit 198b3716dba6, so backpatch down to v14.
Author: Ran Benita <ran@unusedvar.com>
Discussion: https://postgr.es/m/a3383211-4539-459b-9d51-95c736ef08e0@app.fastmail.com
Backpatch-through: 14
Compression in pg_dump is abstracted using an API with multiple
implementations which can be selected at runtime by the user.
The API and its implementations have evolved over time, notable
commits include bf9aa490db, e9960732a9, 84adc8e20, and 0da243fed.
The errorhandling defined by the API was however problematic and
the implementations had a few bugs and/or were not following the
API specification. This commit modifies the API to ensure that
callers can perform errorhandling efficiently and fixes all the
implementations such that they all implement the API in the same
way. A full list of the changes can be seen below.
* write_func:
- Make write_func throw an error on all error conditions. All
callers of write_func were already checking for success and
calling pg_fatal on all errors, so we might as well make the
API support that case directly with simpler errorhandling as
a result.
* open_func:
- zstd: move stream initialization from the open function to
the read and write functions as they can have fatal errors.
Also ensure to dup the file descriptor like none and gzip.
- lz4: Ensure to dup the file descriptor like none and gzip.
* close_func:
- zstd: Ensure to close the file descriptor even if closing
down the compressor fails, and clean up state allocation on
fclose failures. Make sure to capture errors set by fclose.
- lz4: Ensure to close the file descriptor even if closing
down the compressor fails, and instead of calling pg_fatal
log the failures using pg_log_error. Make sure to capture
errors set by fclose.
- none: Make sure to catch errors set by fclose.
* read_func / gets_func:
- Make read_func unconditionally return the number of read
bytes instead of making it optional per implementation.
- lz4: Make sure to call throw an error and not return -1
- gzip: gzread returning zero cannot be assumed to indicate
EOF as it is documented to return zero for some types of
errors.
- lz4, zstd: Convert the _read_internal helper functions to
not call pg_fatal on errors to be able to handle gets_func
returning NULL on error.
* getc_func:
- zstd: Use an unsigned char rather than an int to read char
into.
* LZ4Stream_init:
- Make sure to not switch to inited state until we know that
initialization succeeded and reset errno just in case.
On top of these changes there are minor comment cleanups and
improvements as well as an attempt to consistently reset errno
in codepaths where it is inspected.
This work was initiated by a report of API misuse, which turned
into a larger body of work. As this is an internal API these
changes can be backpatched into all affected branches.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Author: Daniel Gustafsson <daniel@yesql.se> Reported-by: Evgeniy Gorbanev <gorbanyoves@basealt.ru>
Discussion: https://postgr.es/m/517794.1750082166@sss.pgh.pa.us
Backpatch-through: 16
David Rowley [Fri, 29 Aug 2025 12:52:22 +0000 (00:52 +1200)]
Fix possible use after free in expand_partitioned_rtentry()
It's possible that if the only live partition is concurrently dropped
and try_table_open() fails, that the bms_del_member() will pfree the
live_parts Bitmapset. Since the bms_del_member() call does not assign
the result back to the live_parts local variable, the while loop could
segfault as that variable would still reference the pfree'd Bitmapset.
Backpatch to 15. 52f3de874 was backpatched to 14, but there's no
bms_del_member() there due to live_parts not yet existing in RelOptInfo in
that version. Technically there's no bug in version 15 as
bms_del_member() didn't pfree when the set became empty prior to 00b41463c (from v16). Applied to v15 anyway to keep the code similar and
to avoid the bad coding pattern.
Masahiko Sawada [Fri, 29 Aug 2025 00:06:47 +0000 (17:06 -0700)]
Use LW_SHARED in walsummarizer.c for WALSummarizerLock lock where possible.
Previously, we used LW_EXCLUSIVE in several places despite only reading
WalSummarizerCtl fields. This patch reduces the lock level to LW_SHARED
where we are only reading the shared fields.
Backpatch to 17, where wal summarization was introduced.
Tom Lane [Tue, 26 Aug 2025 16:08:57 +0000 (12:08 -0400)]
Put "excludeOnly" GIN scan keys at the end of the scankey array.
Commit 4b754d6c1 introduced the concept of an excludeOnly scan key,
which cannot select matching index entries but can reject
non-matching tuples, for example a tsquery such as '!term'. There are
poorly-documented assumptions that such scan keys do not appear as the
first scan key. ginNewScanKey did nothing to ensure that, however,
with the result that certain GIN index searches could go into an
infinite loop while apparently-equivalent queries with the clauses in
a different order were fine.
Fix by teaching ginNewScanKey to place all excludeOnly scan keys
after all not-excludeOnly ones. So far as we know at present,
it might be sufficient to avoid the case where the very first
scan key is excludeOnly; but I'm not very convinced that there
aren't other dependencies on the ordering.
Bug: #19031 Reported-by: Tim Wood <washwithcare@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/19031-0638148643d25548@postgresql.org
Backpatch-through: 13
Tom Lane [Tue, 26 Aug 2025 15:38:41 +0000 (11:38 -0400)]
Do CHECK_FOR_INTERRUPTS inside, not before, scanGetItem.
The CHECK_FOR_INTERRUPTS call in gingetbitmap turns out to be
inadequate to prevent a long uninterruptible loop, because
we now know a case where looping occurs within scanGetItem.
While the next patch will fix the bug that caused that, it
seems foolish to assume that no similar patterns are possible.
Let's do the CFI within scanGetItem's retry loop, instead.
This demonstrably allows canceling out of the loop exhibited
in bug #19031.
Bug: #19031 Reported-by: Tim Wood <washwithcare@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/19031-0638148643d25548@postgresql.org
Backpatch-through: 13
Noah Misch [Sat, 23 Aug 2025 23:46:20 +0000 (16:46 -0700)]
Rewrite previous commit's test for TestUpgradeXversion compatibility.
v17 introduced the MAINTAIN ON TABLES privilege. That changed the
applicable "baseacls" reaching buildACLCommands(). That yielded
spurious TestUpgradeXversion diffs. Change to use a TYPES privilege.
Types have the same one privilege in all supported versions, so they
avoid the problem. Per buildfarm. Back-patch to v13, like that commit.
Noah Misch [Sat, 23 Aug 2025 03:50:28 +0000 (20:50 -0700)]
Sort DO_DEFAULT_ACL dump objects independent of OIDs.
Commit 0decd5e89db9f5edb9b27351082f0d74aae7a9b6 missed DO_DEFAULT_ACL,
leading to assertion failures, potential dump order instability, and
spurious schema diffs. Back-patch to v13, like that commit.
Amit Kapila [Fri, 22 Aug 2025 05:15:10 +0000 (05:15 +0000)]
Doc: Fix typo in logicaldecoding.sgml.
Author: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Backpatch-through: 17, where it was introduced
Discussion: https://postgr.es/m/OSCPR01MB149662EC5467B4135398E3731F532A@OSCPR01MB14966.jpnprd01.prod.outlook.com
Michael Paquier [Fri, 22 Aug 2025 00:06:36 +0000 (09:06 +0900)]
Ignore temporary relations in RelidByRelfilenumber()
Temporary relations may share the same RelFileNumber with a permanent
relation, or other temporary relations associated with other sessions.
Being able to uniquely identify a temporary relation would require
RelidByRelfilenumber() to know about the proc number of the temporary
relation it wants to identify, something it is not designed for since
its introduction in f01d1ae3a104.
There are currently three callers of RelidByRelfilenumber():
- autoprewarm.
- Logical decoding, reorder buffer.
- pg_filenode_relation(), that attempts to find a relation OID based on
a tablespace OID and a RelFileNumber.
This makes the situation problematic particularly for the first two
cases, leading to the possibility of random ERRORs due to
inconsistencies that temporary relations can create in the cache
maintained by RelidByRelfilenumber(). The third case should be less of
an issue, as I suspect that there are few direct callers of
pg_filenode_relation().
The window where the ERRORs are happen is very narrow, requiring an OID
wraparound to create a lookup conflict in RelidByRelfilenumber() with a
temporary table reusing the same OID as another relation already cached.
The problem is easier to reach in workloads with a high OID consumption
rate, especially with a higher number of temporary relations created.
We could get pg_filenode_relation() and RelidByRelfilenumber() to work
with temporary relations if provided the means to identify them with an
optional proc number given in input, but the years have also shown that
we do not have a use case for it, yet. Note that this could not be
backpatched if pg_filenode_relation() needs changes. It is simpler to
ignore temporary relations.
Reported-by: Shenhao Wang <wangsh.fnst@fujitsu.com>
Author: Vignesh C <vignesh21@gmail.com> Reviewed-By: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> Reviewed-By: Robert Haas <robertmhaas@gmail.com> Reviewed-By: Kyotaro Horiguchi <horikyota.ntt@gmail.com> Reviewed-By: Takamichi Osumi <osumi.takamichi@fujitsu.com> Reviewed-By: Michael Paquier <michael@paquier.xyz> Reviewed-By: Masahiko Sawada <sawada.mshk@gmail.com> Reported-By: Shenhao Wang <wangsh.fnst@fujitsu.com>
Discussion: https://postgr.es/m/bbaaf9f9-ebb2-645f-54bb-34d6efc7ac42@fujitsu.com
Backpatch-through: 13
Michael Paquier [Thu, 21 Aug 2025 04:25:52 +0000 (13:25 +0900)]
doc: Improve description of wal_compression
The description of this GUC provides a list of the situations where
full-page writes are generated. However, it is not completely exact,
mentioning only the cases where full_page_writes=on or base backups. It
is possible to generate full-page writes in more situations than these
two, making the description confusing as it implies that no other cases
exist.
The description is slightly reworded to take into account that other
cases are possible, without mentioning them directly to minimize the
maintenance burden should FPWs be generated in more contexts in the
future.
Michael Paquier [Wed, 20 Aug 2025 06:00:10 +0000 (15:00 +0900)]
Fix assertion failure with replication slot release in single-user mode
Some replication slot manipulations (logical decoding via SQL,
advancing) were failing an assertion when releasing a slot in
single-user mode, because active_pid was not set in a ReplicationSlot
when its slot is acquired.
ReplicationSlotAcquire() has some logic to be able to work with the
single-user mode. This commit sets ReplicationSlot->active_pid to
MyProcPid, to let the slot-related logic fall-through, considering the
single process as the one holding the slot.
Some TAP tests are added for various replication slot functions with the
single-user mode, while on it, for slot creation, drop, advancing, copy
and logical decoding with multiple slot types (temporary, physical vs
logical). These tests are skipped on Windows, as direct calls of
postgres --single would fail on permission failures. There is no
platform-specific behavior that needs to be checked, so living with this
restriction should be fine. The CI is OK with that, now let's see what
the buildfarm tells.
Author: Hayato Kuroda <kuroda.hayato@fujitsu.com> Reviewed-by: Paul A. Jungwirth <pj@illuminatedcomputing.com> Reviewed-by: Mutaamba Maasha <maasha@gmail.com>
Discussion: https://postgr.es/m/OSCPR01MB14966ED588A0328DAEBE8CB25F5FA2@OSCPR01MB14966.jpnprd01.prod.outlook.com
Backpatch-through: 13
Masahiko Sawada [Tue, 19 Aug 2025 19:11:37 +0000 (12:11 -0700)]
Add CHECK_FOR_INTERRUPTS in contrib/pg_buffercache functions.
This commit adds CHECK_FOR_INTERRUPTS to loops iterating over shared
buffers in several pg_buffercache functions, allowing them to be
interrupted during long-running operations.
Backpatch to all supported versions. Add CHECK_FOR_INTERRUPTS to the
loop in pg_buffercache_pages() in all supported branches, and to
pg_buffercache_summary() and pg_buffercache_usage_counts() in version
16 and newer.
Amit Kapila [Tue, 19 Aug 2025 05:06:37 +0000 (05:06 +0000)]
Fix self-deadlock during DROP SUBSCRIPTION.
The DROP SUBSCRIPTION command performs several operations: it stops the
subscription workers, removes subscription-related entries from system
catalogs, and deletes the replication slot on the publisher server.
Previously, this command acquired an AccessExclusiveLock on
pg_subscription before initiating these steps.
However, while holding this lock, the command attempts to connect to the
publisher to remove the replication slot. In cases where the connection is
made to a newly created database on the same server as subscriber, the
cache-building process during connection tries to acquire an
AccessShareLock on pg_subscription, resulting in a self-deadlock.
To resolve this issue, we reduce the lock level on pg_subscription during
DROP SUBSCRIPTION from AccessExclusiveLock to RowExclusiveLock. Earlier,
the higher lock level was used to prevent the launcher from starting a new
worker during the drop operation, as a restarted worker could become
orphaned.
Now, instead of relying on a strict lock, we acquire an AccessShareLock on
the specific subscription being dropped and re-validate its existence
after acquiring the lock. If the subscription is no longer valid, the
worker exits gracefully. This approach avoids the deadlock while still
ensuring that orphan workers are not created.
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Author: Dilip Kumar <dilipbalaut@gmail.com> Reviewed-by: vignesh C <vignesh21@gmail.com> Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com> Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Backpatch-through: 13
Discussion: https://postgr.es/m/18988-7312c868be2d467f@postgresql.org
projects / thirdparty / postgresql.git / log
