Use of a RowCompare key makes nbtree index scans ineligible to use
pstate.forcenonrequired following recent bugfix commit 5f4d98d.
There's no longer any need for _bt_check_rowcompare to accept a
forcenonrequired argument, so remove it.

Refine wording from commit 01463e1.

Author: Noah Misch <noah@leadboat.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/20250605163441.2f.nmisch@google.com

Reported-by: Daria Shanina <vilensipkdm@gmail.com>
Author: Daria Shanina <vilensipkdm@gmail.com>
Author: Robert Haas <robertmhaas@gmail.com>
Backpatch-through: 13

Delay calling BufferGetLSNAtomic() until we finish reading a page that
actually contains items that btgettuple will return to the executor.
This reduces the number of calls during plain index scans (we'll only
call BufferGetLSNAtomic() when _bt_readpage returns true), and totally
eliminates calls during index-only scans, bitmap index scans, and plain
index scans of an unlogged relation.

Currently, when checksums (or wal_log_hints) are enabled, acquiring a
page's LSN in BufferGetLSNAtomic() involves locking the buffer header
(which involves the use of spinlocks).  Testing has shown that enabling
page-level checksums causes large regressions with certain workloads,
especially on larger multi-socket systems.

The regression isn't tied to any Postgres 18 commit.  However, Postgres
18 commit 04bec89 made initdb use checksums by default, so it seems
prudent to address the problem now.

Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: Tomas Vondra <tomas@vondra.me>
Discussion: https://postgr.es/m/941f0190-e3c6-4622-9ac7-c04e936e5fdb@vondra.me
Discussion: https://postgr.es/m/CAH2-Wzk-Dg5XWs_jDuiHt4_7ryrSY+n=vxmHY51EVqPDFsKXmg@mail.gmail.com

Oversight in commit 8b2bcf3.

Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Discussion: https://postgr.es/m/aECi_gSD9JnVWQ8T%40nathan
Backpatch-through: 17

Commit 5fe08c0 fixed this for calls to dshash_create().  This
commit fixes calls to dshash_attach() and dsa_create_in_place().

Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/aECi_gSD9JnVWQ8T%40nathan

Discussion: https://postgr.es/m/73959a14-267b-49c1-8293-291b175682cb@manitou-mail.org
Reviewed-by: Daniel Verite <daniel@manitou-mail.org>

Move plpython_error_5.out to plpython_error.out, since the pre-3.5
version is no longer needed, since we raised the Python requirement to
3.6 (commit 45363fc).

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Jacob Champion <jacob.champion@enterprisedb.com>
Discussion: https://www.postgresql.org/message-id/d620e7c6-becc-4a8e-9b43-eea0da55faf2@eisentraut.org

And move to the top of the incompatibility list.  This will impact users
more than any other incompatibility item because of pg_upgrade.

Reported-by: Noah Misch

Discussion: https://postgr.es/m/20250603172123.5f.nmisch@google.com

…le modes."

We concluded that commit e5a3c9d is a feature rather than a fix; since
it was added after feature freeze, revert it.

Reported-by: Fujii Masao <masao.fujii@oss.nttdata.com>
Reported-by: Michael Paquier <michael@paquier.xyz>
Reported-by: Robert Haas <robertmhaas@gmail.com>
Discussion: https://postgr.es/m/ed2296f1-1a6b-4932-b870-5bb18c2591ae%40oss.nttdata.com

pg_restore failed to restore large objects (blobs) out of
directory-format dumps made by versions before PG v12.
That's because, due to a bug fixed in commit 548e509, those
old versions put the wrong filename into the BLOBS TOC entry.
Said bug was harmless before v17, because we ignored the
incorrect filename field --- but commit a45c78e assumed it
would be correct.

Reported-by: Pavel Stehule <pavel.stehule@gmail.com>
Author: Pavel Stehule <pavel.stehule@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAFj8pRCrZ=_e1Rv1N+6vDaH+6gf=9A2mE2J4RvnvKA1bLiXvXA@mail.gmail.com
Backpatch-through: 17

On macOS, when building with the make system, the exported symbols
list $(SHLIB_EXPORTS) was ignored.  This was probably not intentional,
it was probably just forgotten, since that combination has never
actually been used until now (for libpq-oauth).

The meson build system handles this correctly.  Also, other platforms
have been doing this correctly.

This fixes it.  It also does a bit of refactoring to make the code
match the layout for other platforms.

Reviewed-by: Jacob Champion <jacob.champion@enterprisedb.com>
Discussion: https://www.postgresql.org/message-id/flat/c70ca32e-b109-460d-9810-6e23ebb4473f%40eisentraut.org

Avoid dependence on setlocale(). No behavior change.

Discussion: https://postgr.es/m/9875f7f9-50f1-4b5d-86fc-ee8b03e8c162@eisentraut.org
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>

Avoid dependence on setlocale(). No behavior change.

Discussion: https://postgr.es/m/9875f7f9-50f1-4b5d-86fc-ee8b03e8c162@eisentraut.org
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>

Avoid dependence on setlocale(). No behavior change.

Discussion: https://postgr.es/m/9875f7f9-50f1-4b5d-86fc-ee8b03e8c162@eisentraut.org
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>

Avoid dependence on setlocale(). No behavior change.

Discussion: https://postgr.es/m/9875f7f9-50f1-4b5d-86fc-ee8b03e8c162@eisentraut.org
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>

Traditionally, libpq's pqPutMsgEnd has rounded down the amount-to-send
to be a multiple of 8K when it is eagerly writing some data.  This
still seems like a good idea when sending through a Unix socket, as
pipes typically have a buffer size of 8K or some fraction/multiple of
that.  But there's not much argument for it on a TCP connection, since
(a) standard MTU values are not commensurate with that, and (b) the
kernel typically applies its own packet splitting/merging logic.

Worse, our SSL and GSSAPI code paths both have API stipulations that
if they fail to send all the data that was offered in the previous
write attempt, we mustn't offer less data in the next attempt; else
we may get "SSL error: bad length" or "GSSAPI caller failed to
retransmit all data needing to be retried".  The previous write
attempt might've been pqFlush attempting to send everything in the
buffer, so pqPutMsgEnd can't safely write less than the full buffer
contents.  (Well, we could add some more state to track exactly how
much the previous write attempt was, but there's little value evident
in such extra complication.)  Hence, apply the round-down only on
AF_UNIX sockets, where we never use SSL or GSSAPI.

Interestingly, we had a very closely related bug report before,
which I attempted to fix in commit d053a87.  But the test case
we had then seemingly didn't trigger this pqFlush-then-pqPutMsgEnd
scenario, or at least we failed to recognize this variant of the bug.

Bug: #18907
Reported-by: Dorjpalam Batbaatar <htgn.dbat.95@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/18907-d41b9bcf6f29edda@postgresql.org
Backpatch-through: 13

CREATE UNLOGGED TABLE was still being recommended by psql's tab
completion as a possible pattern, but the backend is rejecting this
option since e2bab2d.

Reported-by: Shinya Kato <shinya11.kato@gmail.com>
Reviewed-by: Nathan Bossart <nathandbossart@gmail.com>
Reviewed-by: Shinya Kato <shinya11.kato@gmail.com>
Discussion: https://postgr.es/m/CAOzEurQZ1a+6d1K8b=+Ww1NFQVwAt9KSCQsBWXYBaPnYCenK3g@mail.gmail.com

Teach nbtree's _bt_killitems to leave the so->currPos page that it sets
LP_DEAD items on in whatever state it was in when _bt_killitems was
called.  In particular, make sure that so->dropPin scans don't acquire a
pin whose reference is saved in so->currPos.buf.

Allowing _bt_killitems to change so->currPos.buf like this is wrong.
The immediate consequence of allowing it is that code in _bt_steppage
(that copies so->currPos into so->markPos) will behave as if the scan is
a !so->dropPin scan.  so->markPos will therefore retain the buffer pin
indefinitely, even though _bt_killitems only needs to acquire a pin
(along with a lock) for long enough to mark known-dead items LP_DEAD.

This issue came to light following a report of a failure of an assertion
from recent commit e6eed40.  The test case in question involves the use
of mark and restore.  An initial call to _bt_killitems takes place that
leaves so->currPos.buf in a state that is inconsistent with the scan
being so->dropPin.  A subsequent call to _bt_killitems for the same
position (following so->currPos being saved in so->markPos, and then
restored as so->currPos) resulted in the failure of an assertion that
tests that so->currPos.buf is InvalidBuffer when the scan is so->dropPin
(non-assert builds got a "resource was not closed" WARNING instead).

The same problem exists on earlier releases, though the issue is far
more subtle there.  Recent commit e6eed40 introduced the so->dropPin
field as a partial replacement for testing so->currPos.buf directly.
Earlier releases won't get an assertion failure (or buffer pin leak),
but they will allow the second _bt_killitems call from the test case to
behave as if a buffer pin was consistently held since the original call
to _bt_readpage.  This is wrong; there will have been an initial window
during which no pin was held on the so->currPos page, and yet the second
_bt_killitems call will neglect to check if so->currPos.lsn continues to
match the page's now-current LSN.

As a result of all this, it's just about possible that _bt_killitems
will set the wrong items LP_DEAD (on release branches).  This could only
happen with merge joins (the sole user of nbtree mark/restore support),
when a concurrently inserted index tuple used a recently-recycled TID
(and only when the new tuple was inserted onto the same page as a
distinct concurrently-removed tuple with the same TID).  This is exactly
the scenario that _bt_killitems' check of the page's now-current LSN
against the LSN stashed in currPos was supposed to prevent.

A follow-up commit will make nbtree completely stop conditioning whether
or not a position's pin needs to be dropped on whether the 'buf' field
is set.  All call sites that might need to drop a still-held pin will be
taught to rely on the scan-level so->dropPin field recently introduced
by commit e6eed40.  That will make bugs of the same general nature as
this one impossible (or make them much easier to detect, at least).

Author: Peter Geoghegan <pg@bowt.ie>
Reported-By: Alexander Lakhin <exclusion@gmail.com>
Discussion: https://postgr.es/m/545be1e5-3786-439a-9257-a90d30f8b849@gmail.com
Backpatch-through: 13

This addresses an oversight in commit 4ac2a9b, which introduced the
REJECT_LIMIT option to the COPY command.

Author: Atsushi Torikoshi <torikoshia@oss.nttdata.com>
Reviewed-by: Yugo Nagata <nagata@sraoss.co.jp>
Discussion: https://postgr.es/m/ac23e824d1d602f113a89c91ee56fb23@oss.nttdata.com

- 4c787a2
- 78bd364
- 7a6880f
- 8898082

Suggested-by: Robert Haas <robertmhaas@gmail.com>
Discussion: https://postgr.es/m/CA+TgmoZ=J=PVNZUNKaxULu+KUVSt3Y-aJ1DZ9Y3Co6mu0z62jA@mail.gmail.com
Discussion: https://postgr.es/m/60e8c6d0a6c08e67f15dbbe9e53df0119c710065.camel@j-davis.com

This reverts commit 54c6ea8.

Further analysis has shown that the forcenonrequired row compare
behavior is in fact necessary, despite the new restrictions on
RowCompares imposed by _bt_set_startikey following commit 5f4d98d.

Discussion: https://postgr.es/m/CAH2-Wzm3bKcz3TbHGem3_+SinEyG=VZVPbApQghp7YiZj+MM3g@mail.gmail.com

This commit reverts the two following commits:
- 499edb0, track more precisely query locations for nested
statements.
- 06450c7, a follow-up fix of 499edb0 with query locations.
The test introduced in this commit is not reverted.  This is proving
useful to track a problem that only pgaudit was able to detect.

These prove to have issues with the tracking of SELECT statements, when
these use multiple parenthesis which is something supported by the
grammar.  Incorrect location and lengths are causing pg_stat_statements
to become confused, failing its job in query normalization with
potential out-of-bound writes because the location and the length may
not match with what can be handled.  A lot of the query patterns
discussed when this issue was reported have no test coverage in the main
regression test suite, or the recovery test 027_stream_regress.pl would
have caught the problems as pg_stat_statements is loaded by the node
running the regression tests.  A first step would be to improve the test
coverage to stress more the query normalization logic.

A different portion of this work was done in 45e0ba3, with the
addition of tests for nested queries.  These can be left in the tree.
They are useful to track the way inner queries are currently tracked by
PGSS with non-top-level entries, and will be useful when reconsidering
in the future the work reverted here.

Reported-by: Alexander Kozhemyakin <a.kozhemyakin@postgrespro.ru>
Discussion: https://postgr.es/m/18947-cdd2668beffe02bf@postgresql.org

…functions.

Database object statistics manipulation functions were introduced
in PostgreSQL 18 and are permitted under the MAINTAIN privilege.
However, the documentation previously did not mention these functions
in the list of allowed operations.

This commit updates the MAINTAIN privilege documentation to
explicitly include statistics manipulation functions, clarifying
what the privilege covers.

Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Robert Treat <rob@xzilla.net>
Discussion: https://postgr.es/m/7c7e1ad5-fdf9-486f-bc63-40ac99b0461d@oss.nttdata.com

The algorithm to squash lists of constants added by commit 62d712e
was a bit too simplistic; we wanted to avoid adding unnecessary
complexity, but cases like direct function calls of typecasting
functions (and others) were missed, and bogus SQL syntax was being shown
in pg_stat_statements normalized query text field.  To fix normalization
for those cases, we need the parser to transmit information about were
each list of constant values starts and ends, so add that to a couple of
nodes.  Also add a few more test cases to make sure we're doing the
right thing.

The patch initially submitted by Sami added a new private struct in
gram.y to carry the start/end information for A_Expr, but I (Álvaro)
decided that a better fix was to remove the parser indirection via the
in_expr production, and instead create separate components in the a_expr
rule.  I'm surprised that this works and doesn't require more changes,
but I assume (without checking) that the grammar used to be more complex
and got simplified at some point.

Bump catversion.

Author: Sami Imseih <samimseih@gmail.com>
Author: Dmitry Dolgov <9erthalion6@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/CAA5RZ0tRXoPG2y6bMgBCWNDt0Tn=unRerbzYM=oW0syi1=C1OA@mail.gmail.com

… options.

Commit bde2fb7 added the --with-schema, --with-data, and --with-statistics
options to pg_restore. These options control whether to restore schema, data,
or statistics if present in the archive. However, the help message and
documentation incorrectly described them as affecting what gets dumped.

This commit corrects those descriptions to clarify that the options control
restoration, not dumping.

Bug: #18952
Reported-by: TAKATSUKA Haruka <harukat@sraoss.co.jp>
Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: TAKATSUKA Haruka <harukat@sraoss.co.jp>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://postgr.es/m/18952-be40a620f8b1e755@postgresql.org

This is a continuation of 15a79c7, cleaning up the AIO io_uring
code that has been committed after that while still using %llu.

The code changed here is new in v18, so cleaning things now means less
conflicts if this area of the code changes on backpatch once the 18
stable branch is created.

Reviewed-by: Nathan Bossart <nathandbossart@gmail.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://postgr.es/m/aEZcGCnYFq642q8k@paquier.xyz

Running COPY within a pipeline can break protocol synchronization in
multiple ways.  psql is limited in terms of result processing if mixing
COPY commands with normal queries while controlling a pipeline with the
new meta-commands, as an effect of the following reasons:
- In COPY mode, the backend ignores additional Sync messages and will
not send a matching ReadyForQuery expected by the frontend.  Doing a
\syncpipeline just after COPY will leave the frontend waiting for a
ReadyForQuery message that won't be sent, leaving psql out-of-sync.
- libpq automatically sends a Sync with the Copy message which is not
tracked in the command queue, creating an unexpected synchronisation
point that psql cannot really know about.  While it is possible to track
such activity for a \copy, this cannot really be done sanely with plain
COPY queries.  Backend failures during a COPY would leave the pipeline
in an aborted state while the backend would be in a clean state, ready
to process commands.

At the end, fixing those issues would require modifications in how libpq
handles pipeline and COPY.  So, rather than implementing workarounds in
psql to shortcut the libpq internals (with command queue handling for
one), and because meta-commands for pipelines in psql are a new feature
with COPY in a pipeline having a limited impact compared to other
queries, this commit forbids the use of COPY within a pipeline to avoid
possible break of protocol synchronisation within psql.  If there is a
use-case for COPY support within pipelines in libpq, this could always
be added in the future, if necessary.

Most of the changes of this commit impacts the tests for psql pipelines,
removing the tests related to COPY.  Some TAP tests still exist for COPY
TO/FROM and \copy to/from, to check that that connections are aborted
when this operation is attempted.

Reported-by: Nikita Kalinin <n.kalinin@postgrespro.ru>
Author: Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com>
Discussion: https://postgr.es/m/AC468509-06E8-4E2A-A4B1-63046A4AC6AB@postgrespro.ru

Reword the documentation around the default value to make interaction
between WATCH_INTERVAL and the \watch command clearer.  While there,
also remove a stray parenthesis left over from a previous version of
the patch.

Reported-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: David G. Johnston <david.g.johnston@gmail.com>
Discussion: https://postgr.es/m/c34a650b-6f8b-4da7-9ebb-b6df03ce009d@eisentraut.org

…N TABLE.

Commit 302cf15 added support for LIKE in CREATE FOREIGN TABLE.
In this feature, since indexes are not created for foreign tables,
comments on indexes are not copied either.

However, the documentation incorrectly stated that index comments
would be copied when using INCLUDING COMMENTS. This commit
corrects that by removing the mention of index comments.

Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/f86cd84f-a6a3-4451-bae7-5cca9e63b06d@oss.nttdata.com

Commit 8492feb added support for parallel CREATE INDEX on GIN indexes.
However, previously two places in the documentation and two in the source
code comments still stated that only B-tree and BRIN indexes support
parallel builds.

This commit updates those references to correctly include GIN indexes.

Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Robert Treat <rob@xzilla.net>
Discussion: https://postgr.es/m/7d27d068-90e2-4022-9bd7-09b0fd3d4f47@oss.nttdata.com

Improve the clarity of LOG messages when a failover logical slot
synchronization fails, making the reasons more explicit for easier
debugging.

Update the documentation to outline scenarios where slot synchronization
can fail, especially during the initial sync, and emphasize that
pg_sync_replication_slot() is primarily intended for testing and
debugging purposes.

We also discussed improving the functionality of
pg_sync_replication_slot() so that it can be used reliably, but we would
take up that work for next version after some more discussion and review.

Reported-by: Suraj Kharage <suraj.kharage@enterprisedb.com>
Author: shveta malik <shveta.malik@gmail.com>
Reviewed-by: Zhijie Hou <houzj.fnst@fujitsu.com>
Reviewed-by: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Backpatch-through: 17, where it was introduced
Discussion: https://postgr.es/m/CAF1DzPWTcg+m+x+oVVB=y4q9=PYYsL_mujVp7uJr-_oUtWNGbA@mail.gmail.com

Increase consistency of --help and man page synopses between pg_dump
and pg_dumpall.  These should now be very similar, as pg_dumpall can
now also produce non-text dump output.  But actually, they had drifted
further apart.

- Use verb "export" consistently, instead of "dump" or "extract".
- Use "SQL script" instead of just "script" or "text file".
- Maintain consistent distinction between SQL script and other
  formats/archives (which is relevant for pg_restore).

Reviewed-by: Robert Treat <rob@xzilla.net>
Discussion: https://www.postgresql.org/message-id/flat/3f71d8a7-095b-4829-9b0b-fce09e9866b3%40eisentraut.org

to be used for PG 18 release notes

In version 17 we added support for cross-partition EXCLUDE
constraints, as long as they included all partition key columns and
compared them with equality (see 8c852ba). I updated the docs for
exclusion constraints, but I missed that the docs for CREATE TABLE
still said that they were not supported. This commit fixes that.

Author: Paul A. Jungwirth <pj@illuminatedcomputing.com>
Co-authored-by: Jeff Davis <pgsql@j-davis.com>
Discussion: https://postgr.es/m/c955d292-b92d-42d1-a2a0-1ec6715a2546@illuminatedcomputing.com
Backpatch-through: 17

The TAP tests that verify logical and physical replication slot behavior
during checkpoints (046_checkpoint_logical_slot.pl and
047_checkpoint_physical_slot.pl) inserted two batches of 2 million rows each,
generating approximately 520 MB of WAL.  On slow machines, or when compiled
with '-DRELCACHE_FORCE_RELEASE -DCATCACHE_FORCE_RELEASE', this caused the
tests to run for 8-9 minutes and occasionally time out, as seen on the
buildfarm animal prion.

This commit modifies the mentioned tests to utilize the $node->advance_wal()
function, thereby reducing runtime. Once we do not use the generated data,
the proposed function is a good alternative, which cuts the total wall-clock
run time.

While here, remove superfluous '\n' characters from several note() calls;
these appeared literally in the build-farm logs and looked odd.  Also, remove
excessive 'shared_preload_libraries' GUC from the config and add a check for
'injection_points' extension availability.

Reported-by: Alexander Lakhin <exclusion@gmail.com>
Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Author: Alexander Korotkov <aekorotkov@gmail.com>
Author: Vitaly Davydov <v.davydov@postgrespro.ru>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Discussion: https://postgr.es/m/fbc5d94e-6fbd-4a64-85d4-c9e284a58eb2%40gmail.com
Backpatch-through: 17

We never create regress.def, and if we did this code would fail to
delete it, because "win" is not the correct PORTNAME for Windows.

This thinko seems to have originated in commit 7a6b562 from 1999,
although it got moved around multiple times since then.

Author: Christoph Berg <myon@debian.org>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/aFVR7R7VDX7y2ruc@msg.df7cb.de

While choosing an autogenerated name for an index, look for
pre-existing relations using a SnapshotDirty snapshot, instead of the
previous behavior that considered only committed-good pg_class rows.
This allows us to detect and avoid conflicts against indexes that are
still being built.

It's still possible to fail due to a race condition, but the window
is now just the amount of time that it takes DefineIndex to validate
all its parameters, call smgrcreate(), and enter the index's pg_class
row.  Formerly the race window covered the entire time needed to
create and fill an index, which could be very long if the table is
large.  Worse, if the conflicting index creation is part of a larger
transaction, it wouldn't be visible till COMMIT.

So this isn't a complete solution, but it should greatly ameliorate
the problem, and the patch is simple enough to be back-patchable.

It might at some point be useful to do the same for pg_constraint
entries (cf. ChooseConstraintName, ConstraintNameExists, and related
functions).  However, in the absence of field complaints, I'll leave
that alone for now.  The relation-name test should be good enough for
index-based constraints, while foreign-key constraints seem to be okay
since they require exclusive locks to create.

Bug: #18959
Reported-by: Maximilian Chrzan <maximilian.chrzan@here.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Dilip Kumar <dilipbalaut@gmail.com>
Discussion: https://postgr.es/m/18959-f63b53b864bb1417@postgresql.org
Backpatch-through: 13

Commit 85e5e22, which added (a forerunner of) this logic,
argued that

    Adding the necessary complexity to make this work doesn't seem like
    it would be repaid in significantly better plans, because in cases
    where such a PHV exists, there is probably a corresponding join order
    constraint that would allow a good plan to be found without using the
    star-schema exception.

The flaw in this claim is that there may be other join-order
restrictions that prevent us from finding a join order that doesn't
involve a "dangerous" PHV.  In particular we now recognize that
small join_collapse_limit or from_collapse_limit could prevent it.
Therefore, let's bite the bullet and make the case work.

We don't have to extend the executor's support for nestloop parameters
as I thought at the time, because we can instead push the evaluation
of the placeholder's expression into the left-hand input of the
NestLoop node.  So there's not really a lot of downside to this
solution, and giving the planner more join-order flexibility should
have value beyond just avoiding failure.

Having said that, there surely is a nonzero risk of introducing
new bugs.  Since this failure mode escaped detection for ten years,
such cases don't seem common enough to justify a lot of risk.
Therefore, let's put this fix into master but leave the back branches
alone (for now anyway).

Bug: #18953
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Diagnosed-by: Richard Guo <guofenglinux@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/18953-1c9883a9d4afeb30@postgresql.org

Specify whether the bucket bounds are inclusive or exclusive,
and improve some other vague language.  Explain the behavior that
occurs when the "low" bound is greater than the "high" bound.
Make width_bucket_numeric's comment more like that for
width_bucket_float8, in particular noting that infinite
bounds are rejected (since they became possible in v14).

Reported-by: Ben Peachey Higdon <bpeacheyhigdon@gmail.com>
Author: Robert Treat <rob@xzilla.net>
Co-authored-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Dean Rasheed <dean.a.rasheed@gmail.com>
Discussion: https://postgr.es/m/2BD74F86-5B89-4AC1-8F13-23CED3546AC1@gmail.com
Backpatch-through: 13

    WARNING: You should add the boolean check kwarg to the run_command call.
             It currently defaults to false,
             but it will default to true in meson 2.0.

Introduced by commit bc46104.

(This only happens in the msvc branch.  All the other run_command
calls are ok.)

Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://www.postgresql.org/message-id/flat/42e13eb0-862a-441e-8d84-4f0fd5f6def0%40eisentraut.org

The problem that led to the workaround in f83f148 was not in fact
a compiler bug, but a failure to zero the upper bits of the vector
register containing the initial scalar CRC value. Fix that and revert
the workaround.

Diagnosed-by: Nathan Bossart <nathandbossart@gmail.com>
Diagnosed-by: Raghuveer Devulapalli <raghuveer.devulapalli@intel.com>
Tested-by: Andy Fan <zhihuifan1213@163.com>
Tested-by: Soumyadeep Chakraborty <soumyadeep2007@gmail.com>
Reviewed-by: Nathan Bossart <nathandbossart@gmail.com>
Reviewed-by: Raghuveer Devulapalli <raghuveer.devulapalli@intel.com>
Discussion: https://postgr.es/m/PH8PR11MB82866B07AA6758D12F699C00FB70A@PH8PR11MB8286.namprd11.prod.outlook.com

Commit 43da394 added a dependency on this intrinsic to our
AVX-512 CRC code.  It turns out this intrinsic was added to
gcc later than the other ones we were using, so that there
are platforms where the new code fails to compile.  Since only
relatively old (pre-gcc-10) compilers are affected, it doesn't
seem worth trying to make the AVX-512 CRC code actually work
on these platforms.  Just add the new intrinsic to the configure
probe, so that we'll conclude the code can't be built.

Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Nathan Bossart <nathandbossart@gmail.com>
Discussion: https://postgr.es/m/3350336.1750690281@sss.pgh.pa.us

ca307d5 introduced keeping WAL segments by slot's last saved restart LSN.
It also added an assertion that the slot's restart LSN never goes backward.
However, situations when the restart LSN goes backward have been spotted by
buildfarm animals and investigated in the thread.

When pg_receivewal starts the replication, it sets the last replayed LSN to
the beginning of the segment, which is older than what
ReplicationSlotReserveWal() set for the slot.  A similar situation can happen
to pg_basebackup.  When standby reconnects to the primary, it sends the last
replayed LSN, which might be older than the last confirmed flush LSN.  In
both these situations, a concurrent checkpoint may trigger an assert trap.

Based on ideas from Vitaly Davydov <v.davydov@postgrespro.ru>,
Hayato Kuroda (Fujitsu) <kuroda.hayato@fujitsu.com>,
Vignesh C <vignesh21@gmail.com>,
Amit Kapila <amit.kapila16@gmail.com>.

Reported-by: Vignesh C <vignesh21@gmail.com>
Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CALDaNm3s-jpQTe1MshsvQ8GO%3DTLj233JCdkQ7uZ6pwqRVpxAdw%40mail.gmail.com
Reviewed-by: Vignesh C <vignesh21@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>

This new test was intended to check the handling of the replication slot's
restart lsn fixed in ca307d5.  However, it also reveals another issue
related to logical decoding.  This commit temporarily removes this test to
keep the buildfarm and CFbot green and avoid distorting others' work.  This
test will be restored once we investigate and fix the issue.

Discussion: https://postgr.es/m/CAAKRu_ZCOzQpEumLFgG_%2Biw3FTa%2BhJ4SRpxzaQBYxxM_ZAzWcA%40mail.gmail.com

\close has been introduced in d55322b to be able to close a
prepared statement using the extended protocol in psql.  Per discussion,
the name "close" is ambiguous.  At the SQL level, CLOSE is used to close
a cursor.  At protocol level, the close message can be used to either
close a statement or a portal.

This patch renames \close to \close_prepared to avoid any ambiguity and
make it clear that this is used to close a prepared statement.  This new
name has been chosen based on the feedback from the author and the
reviewers.

Author: Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: Jelte Fennema-Nio <postgres@jeltef.nl>
Discussion: https://postgr.es/m/3e694442-0df5-4f92-a08f-c5d4c4346b85@eisentraut.org

Remove the part of comment that says we don't allow toggling two_phase
option as that is supported in commit 1462aad.

Author: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Author: Amit Kapila <amit.kapila16@gmail.com>
Discussion: https://postgr.es/m/OSCPR01MB1496656725F3951AEE8749EBDF579A@OSCPR01MB14966.jpnprd01.prod.outlook.com

Previously, the UUID functions documentation defined the "UUID" index entry
to link to the UUID data type page, even though that entry already exists there.
Instead, the UUID functions page should define its own index entry linking
to itself.

This commit updates the UUID index entry in the UUID functions documentation
to point to the correct section, improving navigation and avoiding duplication.

Back-patch to all supported versions.

Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://postgr.es/m/f33e0493-5773-4296-87c5-7ce459054cfe@oss.nttdata.com
Backpatch-through: 13

Virtual generated columns have some special checks in
CheckAttributeType(), mainly to check that domains are not used.  But
this check was only applied during CREATE TABLE, not during ALTER
TABLE.  This fixes that.

Reported-by: jian he <jian.universality@gmail.com>
Discussion: https://www.postgresql.org/message-id/CACJufxE0KHR__-h=zHXbhSNZXMMs4LYo4-dbj8H3YoStYBok1Q@mail.gmail.com

The link returns 404 and no replacement is available in the project
on Sourceforge where the content once was. Since we already link to
resources for both beginner and experienced docs hackers, remove the
the dead link.

Backpatch to all supported versions as the link was added in 8.1.

Author: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Magnus Hagander <magnus@hagander.net>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reported-by: jian he <jian.universality@gmail.com>
Discussion: https://postgr.es/m/CACJufxH=YzQPDOe+2WuYZ7seD-BOyjCBmP6JiErpoSiVZWDRnw@mail.gmail.com
Backpatch-through: 13

If vacuum fails to prune a tuple killed before OldestXmin, it will
decide to freeze its xmax and later error out in pre-freeze checks.

Add a test reproducing this scenario to the recovery suite which creates
a table on a primary, updates the table to generate dead tuples for
vacuum, and then, during the vacuum, uses a replica to force
GlobalVisState->maybe_needed on the primary to move backwards and
precede the value of OldestXmin set at the beginning of vacuuming the
table.

This test is coverage for a case fixed in 83c39a1. The test was
originally committed to master in aa60798 but later reverted in
efcbb76 due to test instability.

The test requires multiple index passes. In Postgres 17+, vacuum uses a
TID store for the dead TIDs that is very space efficient. With the old
minimum maintenance_work_mem of 1 MB, it required a large number of dead
rows to generate enough dead TIDs to force multiple index
vacuuming passes. Once the source code changes were made to allow a
minimum maintenance_work_mem value of 64kB, the test could be made much
faster and more stable.

Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: John Naylor <johncnaylorls@gmail.com>
Reviewed-by: Peter Geoghegan <pg@bowt.ie>
Discussion: https://postgr.es/m/CAAKRu_ZJBkidusDut6i%3DbDCiXzJEp93GC1%2BNFaZt4eqanYF3Kw%40mail.gmail.com
Backpatch-through: 17

In b0635bf, I added an early header check to the Meson OAuth support,
which was intended to duplicate the later checks for
HAVE_SYS_[EVENT|EPOLL]_H. However, I implemented the new test via
check_header() -- which tries to compile -- rather than has_header(),
which just looks for the file's existence.

The distinction matters on OpenBSD, where <sys/event.h> can't be
compiled without including prerequisite headers, so -Dlibcurl=enabled
failed on that platform. Switch to has_header() to fix this.