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Commit Graph

53753 Commits

Author SHA1 Message Date
Tom Lane
7fb8c92404 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
2025-10-23 11:47:46 -04:00
Fujii Masao
10799d025f Add comments explaining overflow entries in the replication lag tracker.
Commit 883a95646a 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 883a95646a was recently applied and backpatched to all
supported branches, this follow-up commit is also backpatched accordingly.

Author: Xuneng Zhou <xunengzhou@gmail.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/CABPTF7VxqQA_DePxyZ7Y8V+ErYyXkmwJ1P6NC+YC+cvxMipWKw@mail.gmail.com
Backpatch-through: 13
2025-10-23 13:26:51 +09:00
Masahiko Sawada
c4a6444a65 Add copyright notice to vacuum_horizon_floor.pl test.
Fix oversight in commit 303ba0573, which was backpatched through 14.

Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/CAD21AoBeFdTJcwUfUYPcEgONab3TS6i1PB9S5cSXcBAmdAdQKw%40mail.gmail.com
Backpatch-through: 14
2025-10-22 17:17:36 -07:00
David Rowley
e4316ec4dd 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.

Reported-by: Emmanuel Touzery <emmanuel.touzery@plandela.si>
Author: David Rowley <dgrowleyml@gmail.com>
Discussion: https://postgr.es/m/DB8P194MB08532256D5BAF894F241C06393F3A@DB8P194MB0853.EURP194.PROD.OUTLOOK.COM
Backpatch-through: 13
2025-10-23 13:14:08 +13:00
Fujii Masao
f106f53df6 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.

Backpatch to all supported versions.

Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Chao Li <lic@highgo.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Álvaro Herrera <alvherre@kurilemu.de>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Discussion: https://postgr.es/m/CAHGQGwFud-cvthCTfusBfKHBS6Jj6kdAPTdLWKvP2qjUX6L_wA@mail.gmail.com
Backpatch-through: 13
2025-10-22 20:14:02 +09:00
Fujii Masao
a7ab6ce6a0 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.

Backpatch to all supported versions.

Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Chao Li <lic@highgo.com>
Reviewed-by: Shinya Kato <shinya11.kato@gmail.com>
Reviewed-by: Xuneng Zhou <xunengzhou@gmail.com>
Discussion: https://postgr.es/m/CAHGQGwGdGQ=1-X-71Caee-LREBUXSzyohkoQJd4yZZCMt24C0g@mail.gmail.com
Backpatch-through: 13
2025-10-22 11:29:13 +09:00
Nathan Bossart
58ba7e5ebf 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.

Discussion: https://postgr.es/m/aPfDOD6F4FaJJd7M%40nathan
Backpatch-through: 13-17
2025-10-21 16:37:29 -05:00
Nathan Bossart
0a358eb45e Add previous commit to .git-blame-ignore-revs.
Backpatch-through: 13
2025-10-21 10:02:19 -05:00
Nathan Bossart
e95010a9c0 Re-pgindent brin.c.
Backpatch-through: 13
2025-10-21 09:56:26 -05:00
David Rowley
eea24eb0ac 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
2025-10-21 20:48:34 +13:00
Michael Paquier
5274f11c17 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 7ca37fb040, 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
2025-10-21 08:08:42 +09:00
Tom Lane
40dc710a61 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
2025-10-19 14:36:58 -04:00
Álvaro Herrera
6062c3db30 Fix pg_dump sorting of foreign key constraints
Apparently, commit 04bc2c42f7 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.

Author: Álvaro Herrera <alvherre@kurilemu.de>
Backpatch-through: 13
Discussion: https://postgr.es/m/202510181201.k6y75v2tpf5r@alvherre.pgsql
2025-10-18 17:50:10 +02:00
Nathan Bossart
f146eb45cb 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
2025-10-17 11:36:50 -05:00
Álvaro Herrera
56cd332f80 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.

Author: Ryo Matsumura <matsumura.ryo@fujitsu.com>
Reviewed-by: Bryan Green <dbryan.green@gmail.com>
Backpatch-through: 13
Discussion: https://postgr.es/m/TYCPR01MB113164770FB0B0BE6ED21E68EE8DCA@TYCPR01MB11316.jpnprd01.prod.outlook.com
2025-10-16 20:21:05 +02:00
Etsuro Fujita
24e74b9621 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.

Oversight in commit 385f337c9.

Reported-by: Kristian Lejao <kristianlejao@gmail.com>
Author: Masahiko Sawada <sawada.mshk@gmail.com>
Co-authored-by: Etsuro Fujita <etsuro.fujita@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Etsuro Fujita <etsuro.fujita@gmail.com>
Discussion: https://postgr.es/m/CAD21AoBpo6Gx55FBOW+9s5X=nUw3Xpq64v35fpDEKsTERnc4TQ@mail.gmail.com
Backpatch-through: 13
2025-10-15 17:15:05 +09:00
Tom Lane
e91eb4ad66 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
2025-10-13 17:56:45 -04:00
David Rowley
715eb62e30 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
2025-10-14 09:27:11 +13:00
Álvaro Herrera
b753be38a4 Stop creating constraints during DETACH CONCURRENTLY
Commit 71f4c8c6f7 (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
2025-10-11 20:30:12 +02:00
Peter Geoghegan
314004021e 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
2025-10-10 14:52:14 -04:00
Michael Paquier
f57f2760e6 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
2025-10-10 09:24:57 +09:00
Tom Lane
f46d77377b 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
2025-10-05 16:27:47 -04:00
Michael Paquier
9b3beb7c6f 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.

Author: Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com>
Discussion: https://postgr.es/m/CAO6_XqpHyF2m73ifV5a=5jhXxH2chk=XrgefY+eWWPe2Eft3=A@mail.gmail.com
Backpatch-through: 13
2025-10-03 14:04:06 +09:00
Michael Paquier
ee2dbcad02 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.

Reported-by: Noah Misch <noah@leadboat.com>
Author: Nitin Motiani <nitinmotiani@google.com>
Reviewed-by: Dilip Kumar <dilipbalaut@gmail.com>
Discussion: https://postgr.es/m/CAH5HC95gT1J3dRYK4qEnaywG8RqjbwDdt04wuj8p39R=HukayA@mail.gmail.com
Backpatch-through: 13
2025-10-02 11:09:17 +09:00
Fujii Masao
cb21e1f92f 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.

Backpatch to all supported versions.

Author: Yugo Nagata <nagata@sraoss.co.jp>
Reviewed-by: Chao Li <lic@highgo.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/20250925110940.ebacc31725758ec47d5432c6@sraoss.co.jp
Backpatch-through: 13
2025-09-30 23:55:02 +09:00
Noah Misch
5816baa9bc Fix StatisticsObjIsVisibleExt() for pg_temp.
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
d99d58cdc8 introduced this.  Back-patch to
v13 (all supported versions).

Reviewed-by: Nathan Bossart <nathandbossart@gmail.com>
Discussion: https://postgr.es/m/20250920162116.2e.nmisch@google.com
Backpatch-through: 13
2025-09-29 11:15:49 -07:00
Tom Lane
0be39b4b1a 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
2025-09-27 14:29:41 -04:00
Fujii Masao
bc476f8b8b 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.

Backpatch to all supported versions.

Author: Jian He <jian.universality@gmail.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/CACJufxHCt00pR9h51AVu6+yPD5J7JQn=7dQXxqacj0XyDhc-fA@mail.gmail.com
Backpatch-through: 13
2025-09-18 11:10:37 +09:00
Tom Lane
31bf096320 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
2025-09-17 16:32:57 -04:00
David Rowley
f78a690347 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
2025-09-17 12:21:29 +12:00
David Rowley
2eb7ea97d8 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
2025-09-17 11:50:58 +12:00
Noah Misch
85d6ed31fc 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 0858f0f96e.

Reviewed-by: Álvaro Herrera <alvherre@kurilemu.de>
Discussion: https://postgr.es/m/20250913020233.fa.nmisch@google.com
Backpatch-through: 13
2025-09-16 09:40:49 -07:00
Fujii Masao
295c0a644a 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.

Backpatch to all supported versions.

Author: Jian He <jian.universality@gmail.com>
Co-authored-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/CACJufxHCt00pR9h51AVu6+yPD5J7JQn=7dQXxqacj0XyDhc-fA@mail.gmail.com
Backpatch-through: 13
2025-09-16 16:46:58 +09:00
Fujii Masao
db900ec358 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.

Backpatch to all supported versions.

Author: Jian He <jian.universality@gmail.com>
Co-authored-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/CACJufxHCt00pR9h51AVu6+yPD5J7JQn=7dQXxqacj0XyDhc-fA@mail.gmail.com
Backpatch-through: 13
2025-09-16 10:38:40 +09:00
Peter Eisentraut
cbd3732cbb CREATE STATISTICS: improve misleading error message
The previous change (commit f225473cba) 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
2025-09-15 12:11:48 +02:00
Peter Eisentraut
fbfc36e947 jit: fix build with LLVM-21
LLVM-21 renamed llvm::GlobalValue::getGUID() to
getGUIDAssumingExternalLinkage(), so add a version guard.

Author: Holger Hoffstätte <holger@applied-asynchrony.com>
Discussion: https://www.postgresql.org/message-id/flat/d25e6e4a-d1b4-84d3-2f8a-6c45b975f53d%40applied-asynchrony.com
2025-09-15 08:32:08 +02:00
Tom Lane
f75ff1b141 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
2025-09-13 16:55:51 -04:00
Michael Paquier
5e131489fe 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 c11453ce0a, cross-checking the
logic for the record generation.

Author: Kirill Reshke <reshkekirill@gmail.com>
Reviewed-by: Andrey Borodin <x4mmm@yandex-team.ru>
Discussion: https://postgr.es/m/CALdSSPj1j=a1d1hVA3oabRFz0hSU3KKrYtZPijw4UPUM7LY9zw@mail.gmail.com
Backpatch-through: 13
2025-09-11 17:17:32 +09:00
Tom Lane
5eab9b0a47 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
2025-09-10 16:05:03 -04:00
Dean Rasheed
ea65c88238 Fix compiler error introduced by 5386bfb9c1.
Per buildfarm member wrasse, void function cannot return a value.
This only affects v13-v17, where an ABI-compatible wrapper function
was added.

Backpatch-through: 13-17
2025-09-04 15:57:18 +01:00
Dean Rasheed
5fd569ef2d 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
2025-09-04 11:36:25 +01:00
Richard Guo
160ef51c8d 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
2025-09-03 16:16:36 +09:00
Michael Paquier
0cc540f0d0 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 198b3716db, 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
2025-09-03 12:54:34 +09:00
Álvaro Herrera
b830f9d674 CREATE STATISTICS: improve misleading error message
I think the error message for a different condition was inadvertently
copied.

This problem seems to have been introduced by commit a4d75c86bf.

Author: Álvaro Herrera <alvherre@kurilemu.de>
Reported-by: jian he <jian.universality@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Backpatch-through: 14
Discussion: https://postgr.es/m/CACJufxEZ48toGH0Em_6vdsT57Y3L8pLF=DZCQ_gCii6=C3MeXw@mail.gmail.com
2025-08-29 14:43:47 +02:00
Tom Lane
4a593043ee 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
2025-08-26 12:08:57 -04:00
Tom Lane
a7da746c11 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
2025-08-26 11:38:41 -04:00
Noah Misch
22c6a44f01 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.

Discussion: https://postgr.es/m/20250823144505.88.nmisch@google.com
Backpatch-through: 13
2025-08-23 16:46:25 -07:00
Noah Misch
4948bb9df4 Sort DO_DEFAULT_ACL dump objects independent of OIDs.
Commit 0decd5e89d missed DO_DEFAULT_ACL,
leading to assertion failures, potential dump order instability, and
spurious schema diffs.  Back-patch to v13, like that commit.

Reported-by: Alexander Lakhin <exclusion@gmail.com>
Author: Kirill Reshke <reshkekirill@gmail.com>
Discussion: https://postgr.es/m/d32aaa8d-df7c-4f94-bcb3-4c85f02bea21@gmail.com
Backpatch-through: 13
2025-08-22 20:50:33 -07:00
Michael Paquier
222130edd8 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 f01d1ae3a1.

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
2025-08-22 09:06:40 +09:00
Michael Paquier
24145bbb9e 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.

Author: Jingtang Zhang <mrdrivingduck@gmail.com>
Reviewed-by: Andrey Borodin <x4mmm@yandex-team.ru>
Reviewed-by: Xuneng Zhou <xunengzhou@gmail.com>
Discussion: https://postgr.es/m/CAPsk3_CtAYa_fy4p6=x7qtoutrdKvg1kGk46D5fsE=sMt2546g@mail.gmail.com
Backpatch-through: 13
2025-08-21 13:25:56 +09:00