Commit graph

4102 commits

Author SHA1 Message Date
Álvaro Herrera
758479213d
Remove doc and code comments about ON CONFLICT deficiencies
They have been fixed, so we don't need this text anymore.  This reverts
commit 8b18ed6dfb.

Author: Mihail Nikalayeu <mihailnikalayeu@gmail.com>
Discussion: https://postgr.es/m/CADzfLwWo+FV9WSeOah9F1r=4haa6eay1hNvYYy_WfziJeK+aLQ@mail.gmail.com
2025-12-02 16:47:18 +01:00
Fujii Masao
246ec4a51c doc: Fix misleading synopsis for CREATE/ALTER PUBLICATION.
The documentation for CREATE/ALTER PUBLICATION previously showed:

        [ ONLY ] table_name [ * ] [ ( column_name [, ... ] ) ] [ WHERE ( expression ) ] [, ... ]

to indicate that the table/column specification could be repeated.
However, placing [, ... ] directly after a multi-part construct was
misleading and made it unclear which portion was repeatable.

This commit introduces a new term, table_and_columns, to represent:

        [ ONLY ] table_name [ * ] [ ( column_name [, ... ] ) ] [ WHERE ( expression ) ]

and updates the synopsis to use:

        table_and_columns [, ... ]

which clearly identifies the repeatable element.

Backpatched to v15, where the misleading syntax was introduced.

Author: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: Chao Li <lic@highgo.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/CAHut+PtsyvYL3KmA6C8f0ZpXQ=7FEqQtETVy-BOF+cm9WPvfMQ@mail.gmail.com
Backpatch-through: 15
2025-11-27 23:29:57 +09:00
Daniel Gustafsson
e396a18f32 doc: Fix typo in pg_dump documentation
Reported-by: Erik Rijkers <er@xs4all.nl>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/7596672c-43e8-a030-0850-2dd09af98cac@xs4all.nl
2025-11-27 09:25:56 +01:00
Daniel Gustafsson
fa0ffa2877 doc: Assorted documentation improvements
A set of wording improvements and spelling fixes.

Author: Oleg Sibiryakov <o.sibiryakov@postgrespro.ru>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://postgr.es/m/e62bedb5-c26f-4d37-b4ed-ce9b55f1e980@postgrespro.ru
2025-11-20 15:04:41 +01:00
Fujii Masao
aaf035790a doc: Update pg_upgrade documentation to match recent description changes.
Commit 792353f7d5 updated the pg_dump and pg_dumpall documentation to
clarify which statistics are not included in their output. The pg_upgrade
documentation contained a nearly identical description, but it was not updated
at the same time.

This commit updates the pg_upgrade documentation to match those changes.

Backpatch to v18, where commit 792353f7d5 was backpatched to.

Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Bruce Momjian <bruce@momjian.us>
Discussion: https://postgr.es/m/CAHGQGwFnfgdGz8aGWVzgFCFwoWQU7KnFFjmxinf4RkQAkzmR+w@mail.gmail.com
Backpatch-through: 18
2025-11-20 09:18:51 +09:00
Amit Kapila
c677f2b09f Doc: Use <structfield> markup for sequence fields.
Following commit 980a855c5c, update documentation to use <structfield> for
sequence columns. Previously, these were incorrectly marked up as <literal>.

Author: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/CAHut+PtpDMUE3Kd1p=1ff9pw2HMbgQCpowE_0Hd6gs5v2pKfQg@mail.gmail.com
2025-11-18 03:48:00 +00:00
Bruce Momjian
792353f7d5 doc: clarify that pg_upgrade preserves "optimizer" stats.
Reported-by: Rambabu V

Author: Robert Treat

Discussion: https://postgr.es/m/CADtiZxrUzRRX6edyN2y-7U5HA8KSXttee7K=EFTLXjwG1SCE4A@mail.gmail.com

Backpatch-through: 18
2025-11-17 18:55:41 -05:00
Fujii Masao
6793d6a839 doc: Document default values for some pg_recvlogical options.
The documentation did not previously mention the default values for
the --fsync-interval and --plugin options, even though pg_recvlogical --help
shows them. This omission made it harder for users to understand
the tool's behavior from the documentation alone.

This commit adds the missing default value descriptions for both options
to the pg_recvlogical documentation.

Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Laurenz Albe <laurenz.albe@cybertec.at>
Discussion: https://postgr.es/m/CAHGQGwFqssPBjkWMFofGq32e_tANOeWN-cM=6biAP3nnFUXMRw@mail.gmail.com
2025-11-17 23:24:39 +09:00
Bruce Momjian
43e6929bb2 doc: double-quote use of %f, %p, and %r in literal commands.
Path expansion might expose characters like spaces which would cause
command failure, so double-quote the examples.  While %f doesn't need
quoting since it uses a fixed character set, it is best to be
consistent.

Discussion: https://postgr.es/m/aROPCQCfvKp9Htk4@momjian.us

Backpatch-through: master
2025-11-14 09:08:53 -05:00
Álvaro Herrera
e4018f891d
Doc: add IDs to copy.sgml's <varlistentry> and <refsect1>
In the spirit of commit 78ee60ed84.

Author: jian he <jian.universality@gmail.com>
Discussion: https://postgr.es/m/CACJufxFsPXCwSVR+_vScZ3bysh4-dpE19iVyeta30uNHwnwnSw@mail.gmail.com
2025-11-14 11:45:13 +01:00
Dean Rasheed
7dc4fa9141 doc: Improve description of RLS policies applied by command type.
On the CREATE POLICY page, the "Policies Applied by Command Type"
table was missing MERGE ... THEN DELETE and some of the policies
applied during INSERT ... ON CONFLICT and MERGE. Fix that, and try to
improve readability by listing the various MERGE cases separately,
rather than together with INSERT/UPDATE/DELETE. Mention COPY ... TO
along with SELECT, since it behaves in the same way. In addition,
document which policy violations cause errors to be thrown, and which
just cause rows to be silently ignored.

Also, a paragraph above the table states that INSERT ... ON CONFLICT
DO UPDATE only checks the WITH CHECK expressions of INSERT policies
for rows appended to the relation by the INSERT path, which is
incorrect -- all rows proposed for insertion are checked, regardless
of whether they end up being inserted. Fix that, and also mention that
the same applies to INSERT ... ON CONFLICT DO NOTHING.

In addition, in various other places on that page, clarify how the
different types of policy are applied to different commands, and
whether or not errors are thrown when policy checks do not pass.

Backpatch to all supported versions. Prior to v17, MERGE did not
support RETURNING, and so MERGE ... THEN INSERT would never check new
rows against SELECT policies. Prior to v15, MERGE was not supported at
all.

Author: Dean Rasheed <dean.a.rasheed@gmail.com>
Reviewed-by: Viktor Holmberg <v@viktorh.net>
Reviewed-by: Jian He <jian.universality@gmail.com>
Discussion: https://postgr.es/m/CAEZATCWqnfeChjK=n1V_dYZT4rt4mnq+ybf9c0qXDYTVMsy8pg@mail.gmail.com
Backpatch-through: 14
2025-11-13 12:00:56 +00:00
Amit Kapila
55cefadde8 Doc: Add documentation for sequence synchronization.
Add documentation describing sequence synchronization support in logical
replication. It explains how sequence changes are synchronized from the
publisher to the subscriber, the configuration requirements, and provide
examples illustrating setup and usage.

Additionally, document the pg_get_sequence_data() function, which allows
users to query sequence details on the publisher to determine when to
refresh corresponding sequences on the subscriber.

Author: Vignesh C <vignesh21@gmail.com>
Reviewed-by: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: shveta malik <shveta.malik@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Discussion: https://postgr.es/m/CAA4eK1LC+KJiAkSrpE_NwvNdidw9F2os7GERUeSxSKv71gXysQ@mail.gmail.com
2025-11-12 08:49:01 +00:00
Fujii Masao
df53fa1c1e doc: Fix incorrect synopsis for ALTER PUBLICATION ... DROP ...
The synopsis for the ALTER PUBLICATION ... DROP ... command incorrectly
implied that a column list and WHERE clause could be specified as part of
the publication object. However, these options are not allowed for
DROP operations, making the documentation misleading.

This commit corrects the synopsis  to clearly show only the valid forms
of publication objects.

Backpatched to v15, where the incorrect synopsis was introduced.

Author: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/CAHut+PsPu+47Q7b0o6h1r-qSt90U3zgbAHMHUag5o5E1Lo+=uw@mail.gmail.com
Backpatch-through: 15
2025-11-12 13:37:58 +09:00
Bruce Momjian
980a855c5c doc: consistently use "structname" and "structfield" markup
Previously "literal" and "classname" were used, inconsistently, for
SQL table and column names.

Reported-by: Peter Smith

Author: Peter Smith

Discussion: https://postgr.es/m/CAHut+Pvtf24r+bdPgBind84dBLPvgNL7aB+=HxAUupdPuo2gRg@mail.gmail.com

Backpatch-through: master
2025-11-08 09:49:43 -05:00
Daniel Gustafsson
07961ef866 doc: Fix incorrect wording for --file in pg_dump
The documentation stated that the directory specified by --file
must not exist, but pg_dump does allow for empty directories to
be specified and used.

Author: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Bruce Momjian <bruce@momjian.us>
Discussion: https://postgr.es/m/534AA60D-CF6B-432F-9882-E9737B33D1B7@gmail.com
2025-11-07 15:10:50 +01:00
Fujii Masao
0ab208fa50 pgbench: Add --continue-on-error option.
This commit adds the --continue-on-error option, allowing pgbench clients
to continue running even when SQL statements fail for reasons other than
serialization or deadlock errors. Without this option (by default),
the clients aborts in such cases, which was the only available behavior
previously.

This option is useful for benchmarks using custom scripts that may
raise errors, such as unique constraint violations, where users want
pgbench to complete the run despite individual statement failures.

Author: Rintaro Ikeda <ikedarintarof@oss.nttdata.com>
Co-authored-by: Yugo Nagata <nagata@sraoss.co.jp>
Co-authored-by: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Stepan Neretin <slpmcf@gmail.com>
Reviewed-by: Matthias van de Meent <boekewurm+postgres@gmail.com>
Reviewed-by: Dilip Kumar <dilipbalaut@gmail.com>
Reviewed-by: Srinath Reddy Sadipiralla <srinath2133@gmail.com>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com>
Reviewed-by: Chao Li <lic@highgo.com>
Discussion: https://postgr.es/m/44334231a4d214fac382a69cceb7d9fc@oss.nttdata.com
2025-11-07 19:17:37 +09:00
David Rowley
49d43faa83 Doc: use uppercase keywords in SQLs
Use uppercase SQL keywords consistently throughout the documentation to
ease reading.  Also add whitespace in a couple of places where it
improves readability.

Author: Erik Wienhold <ewie@ewie.name>
Reviewed-by: David Rowley <dgrowleyml@gmail.com>
Discussion: https://postgr.es/m/82eb512b-8ed2-46be-b311-54ffd26978c4%40ewie.name
2025-11-06 16:03:02 +13:00
Alexander Korotkov
447aae13b0 Implement WAIT FOR command
WAIT FOR is to be used on standby and specifies waiting for
the specific WAL location to be replayed.  This option is useful when
the user makes some data changes on primary and needs a guarantee to see
these changes are on standby.

WAIT FOR needs to wait without any snapshot held.  Otherwise, the snapshot
could prevent the replay of WAL records, implying a kind of self-deadlock.
This is why separate utility command seems appears to be the most robust
way to implement this functionality.  It's not possible to implement this as
a function.  Previous experience shows that stored procedures also have
limitation in this aspect.

Discussion: https://www.postgresql.org/message-id/flat/CAPpHfdsjtZLVzxjGT8rJHCYbM0D5dwkO+BBjcirozJ6nYbOW8Q@mail.gmail.com
Discussion: https://www.postgresql.org/message-id/flat/CABPTF7UNft368x-RgOXkfj475OwEbp%2BVVO-wEXz7StgjD_%3D6sw%40mail.gmail.com
Author: Kartyshov Ivan <i.kartyshov@postgrespro.ru>
Author: Alexander Korotkov <aekorotkov@gmail.com>
Author: Xuneng Zhou <xunengzhou@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Reviewed-by: Dilip Kumar <dilipbalaut@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Alexander Lakhin <exclusion@gmail.com>
Reviewed-by: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Reviewed-by: Euler Taveira <euler@eulerto.com>
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Reviewed-by: jian he <jian.universality@gmail.com>
Reviewed-by: Álvaro Herrera <alvherre@kurilemu.de>
Reviewed-by: Xuneng Zhou <xunengzhou@gmail.com>
2025-11-05 11:44:13 +02:00
Tom Lane
ff4597acd4 Allow "SET list_guc TO NULL" to specify setting the GUC to empty.
We have never had a SET syntax that allows setting a GUC_LIST_INPUT
parameter to be an empty list.  A locution such as
	SET search_path = '';
doesn't mean that; it means setting the GUC to contain a single item
that is an empty string.  (For search_path the net effect is much the
same, because search_path ignores invalid schema names and '' must be
invalid.)  This is confusing, not least because configuration-file
entries and the set_config() function can easily produce empty-list
values.

We considered making the empty-string syntax do this, but that would
foreclose ever allowing empty-string items to be valid in list GUCs.
While there isn't any obvious use-case for that today, it feels like
the kind of restriction that might hurt someday.  Instead, let's
accept the forbidden-up-to-now value NULL and treat that as meaning an
empty list.  (An objection to this could be "what if we someday want
to allow NULL as a GUC value?".  That seems unlikely though, and even
if we did allow it for scalar GUCs, we could continue to treat it as
meaning an empty list for list GUCs.)

Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Andrei Klychkov <andrew.a.klychkov@gmail.com>
Reviewed-by: Jim Jones <jim.jones@uni-muenster.de>
Discussion: https://postgr.es/m/CA+mfrmwsBmYsJayWjc8bJmicxc3phZcHHY=yW5aYe=P-1d_4bg@mail.gmail.com
2025-11-04 12:37:40 -05:00
Noah Misch
8b18ed6dfb Doc: cover index CONCURRENTLY causing errors in INSERT ... ON CONFLICT.
Author: Mikhail Nikalayeu <mihailnikalayeu@gmail.com>
Reviewed-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/CANtu0ojXmqjmEzp-=aJSxjsdE76iAsRgHBoK0QtYHimb_mEfsg@mail.gmail.com
Backpatch-through: 13
2025-11-03 12:57:09 -08:00
Álvaro Herrera
645cb44c54
Add \pset options for boolean value display
New \pset variables display_true and display_false allow the user to
change how true and false values are displayed.

Author: David G. Johnston <David.G.Johnston@gmail.com>
Reviewed-by: Álvaro Herrera <alvherre@kurilemu.de>
Discussion: https://postgr.es/m/CAKFQuwYts3vnfQ5AoKhEaKMTNMfJ443MW2kFswKwzn7fiofkrw@mail.gmail.com
Discussion: https://postgr.es/m/56308F56.8060908@joh.to
2025-11-03 17:40:39 +01:00
Michael Paquier
5ab0b6a248 Expose wal_fpi_bytes in EXPLAIN (WAL)
The new wal_fpi_bytes counter calculates the total amount of full page
images inserted in WAL records, in bytes.  This commit exposes this
information in EXPLAIN (ANALYZE, WAL) alongside the existing counters,
for both the text and JSON/YAML outputs, building upon f9a09aa295.

Author: Shinya Kato <shinya11.kato@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discusssion: https://postgr.es/m/CAOzEurQtZEAfg6P0kU3Wa-f9BWQOi0RzJEMPN56wNTOmJLmfaQ@mail.gmail.com
2025-10-30 15:34:01 +09:00
Nathan Bossart
b3ce55f413 Add psql PROMPT variable for search_path.
The new %S substitution shows the current value of search_path.
Note that this only works when connected to Postgres v18 or newer,
since search_path was first marked as GUC_REPORT in commit
28a1121fd9.  On older versions that don't report search_path, %S is
replaced with a question mark.

Suggested-by: Lauri Siltanen <lauri.siltanen@gmail.com>
Author: Florents Tselai <florents.tselai@gmail.com>
Reviewed-by: Jelte Fennema-Nio <postgres@jeltef.nl>
Reviewed-by: Jim Jones <jim.jones@uni-muenster.de>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/CANsM767JhTKCRagTaq5Lz52fVwLPVkhSpyD1C%2BOrridGv0SO0A%40mail.gmail.com
2025-10-28 14:08:38 -05:00
Michael Paquier
5173bfd044 pg_rewind: Skip copy of WAL segments generated before point of divergence
This commit makes the way WAL segments are handled from the source to
the target server slightly smarter: the copy of the WAL segments is now
skipped if these have been created before the point where source and
target have diverged (the WAL segment where the point of divergence
exists is still copied), because we know that such segments exist on
both the target and source.  Note that the on-disk size of the WAL
segments on the source and target need to match.  Hence, only the
segments generated after the point of divergence are now copied.  A
segment existing on the source but not the target is copied.

Previously, all the WAL segments were just copied in full.  This change
can make the rewind operation cheaper in some configurations, especially
for setups where some WAL retention causes many segments to remain on
the source server even after the promotion of a standby used as source
to rewind a previous primary.

A TAP test is added to track these new behaviors.  The file map printed
with --debug now includes all the information related to WAL segments,
to be able to track if these are copied or skipped, and the test relies
on the debug output generated.

Author: John Hsu <johnhyvr@gmail.com>
Author: Justin Kwan <justinpkwan@outlook.com>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
Reviewed-by: Japin Li <japinli@hotmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Srinath Reddy Sadipiralla <srinath2133@gmail.com>
Discussion: https://postgr.es/m/181b4c6fa9c.b8b725681941212.7547232617810891479@viggy28.dev
2025-10-25 09:07:31 +09:00
Amit Kapila
f0b3573c3a Introduce "REFRESH SEQUENCES" for subscriptions.
This patch adds support for a new SQL command:
ALTER SUBSCRIPTION ... REFRESH SEQUENCES
This command updates the sequence entries present in the
pg_subscription_rel catalog table with the INIT state to trigger
resynchronization.

In addition to the new command, the following subscription commands have
been enhanced to automatically refresh sequence mappings:
ALTER SUBSCRIPTION ... REFRESH PUBLICATION
ALTER SUBSCRIPTION ... ADD PUBLICATION
ALTER SUBSCRIPTION ... DROP PUBLICATION
ALTER SUBSCRIPTION ... SET PUBLICATION

These commands will perform the following actions:
Add newly published sequences that are not yet part of the subscription.
Remove sequences that are no longer included in the publication.

This ensures that sequence replication remains aligned with the current
state of the publication on the publisher side.

Note that the actual synchronization of sequence data/values will be
handled in a subsequent patch that introduces a dedicated sequence sync
worker.

Author: Vignesh C <vignesh21@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: shveta malik <shveta.malik@gmail.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Dilip Kumar <dilipbalaut@gmail.com>
Reviewed-by: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: Nisha Moond <nisha.moond412@gmail.com>
Reviewed-by: Shlok Kyal <shlok.kyal.oss@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Hou Zhijie <houzj.fnst@fujitsu.com>
Discussion: https://postgr.es/m/CAA4eK1LC+KJiAkSrpE_NwvNdidw9F2os7GERUeSxSKv71gXysQ@mail.gmail.com
2025-10-23 08:30:27 +00:00
Masahiko Sawada
4bea91f21f Support COPY TO for partitioned tables.
Previously, COPY TO command didn't support directly specifying
partitioned tables so users had to use COPY (SELECT ...) TO variant.

This commit adds direct COPY TO support for partitioned
tables, improving both usability and performance. Performance tests
show it's faster than the COPY (SELECT ...) TO variant as it avoids
the overheads of query processing and sending results to the COPY TO
command.

When used with partitioned tables, COPY TO copies the same rows as
SELECT * FROM table. Row-level security policies of the partitioned
table are applied in the same way as when executing COPY TO on a plain
table.

Author: jian he <jian.universality@gmail.com>
Reviewed-by: vignesh C <vignesh21@gmail.com>
Reviewed-by: David Rowley <dgrowleyml@gmail.com>
Reviewed-by: Melih Mutlu <m.melihmutlu@gmail.com>
Reviewed-by: Kirill Reshke <reshkekirill@gmail.com>
Reviewed-by: Atsushi Torikoshi <torikoshia@oss.nttdata.com>
Reviewed-by: Álvaro Herrera <alvherre@kurilemu.de>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/CACJufxEZt%2BG19Ors3bQUq-42-61__C%3Dy5k2wk%3DsHEFRusu7%3DiQ%40mail.gmail.com
2025-10-20 10:38:52 -07:00
Michael Paquier
a7c3042200 pg_checksums: Use new routine to retrieve data of PG_VERSION
Previously, attempting to use pg_checksums on a cluster with a control
file whose version does not match with what thetool is able to support
would lead to the following error:
pg_checksums: error: pg_control CRC value is incorrect

This is confusing, because it would look like the control file is
corrupted.  However, the contents of the control file are correct,
pg_checksums not being able to understand how the past control file is
shaped.

This commit adds a check based on PG_VERSION, using the facility added
by cd0be131ba, using the same error message as some of the other
frontend tools.  A note is added in the documentation about the major
version requirement.

Author: Michael Banck <mbanck@gmx.net>
Discussion: https://postgr.es/m/68f1ff21.170a0220.2c9b5f.4df5@mx.google.com
2025-10-20 09:35:22 +09:00
Peter Eisentraut
dd3ae37830 Add log_autoanalyze_min_duration
The log output functionality of log_autovacuum_min_duration applies to
both VACUUM and ANALYZE, so it is not possible to separate the VACUUM
and ANALYZE log output thresholds. Logs are likely to be output only for
VACUUM and not for ANALYZE.

Therefore, we decided to separate the threshold for log output of VACUUM
by autovacuum (log_autovacuum_min_duration) and the threshold for log
output of ANALYZE by autovacuum (log_autoanalyze_min_duration).

Author: Shinya Kato <shinya11.kato@gmail.com>
Reviewed-by: Kasahara Tatsuhito <kasaharatt@oss.nttdata.com>
Discussion: https://www.postgresql.org/message-id/flat/CAOzEurQtfV4MxJiWT-XDnimEeZAY+rgzVSLe8YsyEKhZcajzSA@mail.gmail.com
2025-10-15 14:31:12 +02:00
David Rowley
615a0fc2f1 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 09:25:02 +13:00
Amit Kapila
96b3784973 Add "ALL SEQUENCES" support to publications.
This patch adds support for the ALL SEQUENCES clause in publications,
enabling synchronization/replication of all sequences that is useful for
upgrades.

Publications can now include all sequences via FOR ALL SEQUENCES.
psql enhancements:
\d shows publications for a given sequence.
\dRp indicates if a publication includes all sequences.

ALL SEQUENCES can be combined with ALL TABLES, but not with other options
like TABLE or TABLES IN SCHEMA. We can extend support for more granular
clauses in future.

The view pg_publication_sequences provides information about the mapping
between publications and sequences.

This patch enables publishing of sequences; subscriber-side support will
be added in upcoming patches.

Author: vignesh C <vignesh21@gmail.com>
Author: Tomas Vondra <tomas@vondra.me>
Reviewed-by: shveta malik <shveta.malik@gmail.com>
Reviewed-by: Dilip Kumar <dilipbalaut@gmail.com>
Reviewed-by: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Nisha Moond <nisha.moond412@gmail.com>
Reviewed-by: Shlok Kyal <shlok.kyal.oss@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Discussion: https://postgr.es/m/CAA4eK1LC+KJiAkSrpE_NwvNdidw9F2os7GERUeSxSKv71gXysQ@mail.gmail.com
2025-10-09 03:48:54 +00:00
Richard Guo
185e304263 Allow negative aggtransspace to indicate unbounded state size
This patch reuses the existing aggtransspace in pg_aggregate to
signal that an aggregate's transition state can grow unboundedly.  If
aggtransspace is set to a negative value, it now indicates that the
transition state may consume unpredictable or large amounts of memory,
such as in aggregates like array_agg or string_agg that accumulate
input rows.

This information can be used by the planner to avoid applying
memory-sensitive optimizations (e.g., eager aggregation) when there is
a risk of excessive memory usage during partial aggregation.

Bump catalog version.

Per idea from Robert Haas, though applied differently than originally
suggested.

Discussion: https://postgr.es/m/CA+TgmoYbkvYwLa+1vOP7RDY7kO2=A7rppoPusoRXe44VDOGBPg@mail.gmail.com
2025-10-08 17:01:48 +09:00
Tom Lane
ef38a4d975 Add GROUP BY ALL.
GROUP BY ALL is a form of GROUP BY that adds any TargetExpr that does
not contain an aggregate or window function into the groupClause of
the query, making it exactly equivalent to specifying those same
expressions in an explicit GROUP BY list.

This feature is useful for certain kinds of data exploration.  It's
already present in some other DBMSes, and the SQL committee recently
accepted it into the standard, so we can be reasonably confident in
the syntax being stable.  We do have to invent part of the semantics,
as the standard doesn't allow for expressions in GROUP BY, so they
haven't specified what to do with window functions.  We assume that
those should be treated like aggregates, i.e., left out of the
constructed GROUP BY list.

In passing, wordsmith some existing documentation about GROUP BY,
and update some neglected synopsis entries in select_into.sgml.

Author: David Christensen <david@pgguru.net>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAHM0NXjz0kDwtzoe-fnHAqPB1qA8_VJN0XAmCgUZ+iPnvP5LbA@mail.gmail.com
2025-09-29 16:55:17 -04:00
Fujii Masao
668de04309 pgbench: Fix typo in documentation.
This commit fixes a typo introduced in commit b6290ea48e.

Reported off-list by Erik Rijkers <er@xs4all.nl>
2025-09-25 14:06:12 +09:00
Fujii Masao
b6290ea48e pgbench: Clarify documentation for \gset and \aset.
This commit updates the pgbench documentation to list \gset and \aset
as separate terms for easier reading. It also clarifies that \gset raises
an error if the query returns zero or multiple rows, and explains how to
detect cases where the query with \aset returned no rows.

Author: Yugo Nagata <nagata@sraoss.co.jp>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/20250626180125.5b896902a3d0bcd93f86c240@sraoss.co.jp
2025-09-25 12:09:32 +09:00
Daniel Gustafsson
a48d1ef586 doc: Remove trailing whitespace in xref
Remove stray whitespace in xref tag.

This was found due to a regression in xmllint 2.15.0 which flagged
this as an error, and at the time of this commit no fix for xmllint
has shipped.

Author: Erik Wienhold <ewie@ewie.name>
Discussion: https://postgr.es/m/f4c4661b-4e60-4c10-9336-768b7b55c084@ewie.name
Backpatch-through: 17
2025-09-22 10:12:31 +02:00
Tom Lane
8abbbbae61 Revert "Avoid race condition between "GRANT role" and "DROP ROLE"".
This reverts commit 98fc31d649.
That change allowed DROP OWNED BY to drop grants of the target
role to other roles, arguing that nobody would need those
privileges anymore.  But that's not so: if you're not superuser,
you still need admin privilege on the target role so you can
drop it.

It's not clear whether or how the dependency-based approach
to solving the original problem can be adapted to keep these
grants.  Since v18 release is fast approaching, the sanest
thing to do seems to be to revert this patch for now.  The
race-condition problem is low severity and not worth taking
risks for.

I didn't force a catversion bump in 98fc31d64, so I won't do
so here either.

Reported-by: Dipesh Dhameliya <dipeshdhameliya125@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CABgZEgczOFicCJoqtrH9gbYMe_BV3Hq8zzCBRcMgmU6LRsihUA@mail.gmail.com
Backpatch-through: 18
2025-09-16 13:05:53 -04:00
Amit Kapila
0d48d393d4 Resume conflict-relevant data retention automatically.
This commit resumes automatic retention of conflict-relevant data for a
subscription. Previously, retention would stop if the apply process failed
to advance its xmin (oldest_nonremovable_xid) within the configured
max_retention_duration and user needs to manually re-enable
retain_dead_tuples option. With this change, retention will resume
automatically once the apply worker catches up and begins advancing its
xmin (oldest_nonremovable_xid) within the configured threshold.

Author: Zhijie Hou <houzj.fnst@fujitsu.com>
Reviewed-by: shveta malik <shveta.malik@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Dilip Kumar <dilipbalaut@gmail.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Discussion: https://postgr.es/m/OS0PR01MB5716BE80DAEB0EE2A6A5D1F5949D2@OS0PR01MB5716.jpnprd01.prod.outlook.com
2025-09-15 08:46:55 +00:00
Amit Kapila
a850be2fe6 Add max_retention_duration option to subscriptions.
This commit introduces a new subscription parameter,
max_retention_duration, aimed at mitigating excessive accumulation of dead
tuples when retain_dead_tuples is enabled and the apply worker lags behind
the publisher.

When the time spent advancing a non-removable transaction ID exceeds the
max_retention_duration threshold, the apply worker will stop retaining
conflict detection information. In such cases, the conflict slot's xmin
will be set to InvalidTransactionId, provided that all apply workers
associated with the subscription (with retain_dead_tuples enabled) confirm
the retention duration has been exceeded.

To ensure retention status persists across server restarts, a new column
subretentionactive has been added to the pg_subscription catalog. This
prevents unnecessary reactivation of retention logic after a restart.

The conflict detection slot will not be automatically re-initialized
unless a new subscription is created with retain_dead_tuples = true, or
the user manually re-enables retain_dead_tuples.

A future patch will introduce support for automatic slot re-initialization
once at least one apply worker confirms that the retention duration is
within the configured max_retention_duration.

Author: Zhijie Hou <houzj.fnst@fujitsu.com>
Reviewed-by: shveta malik <shveta.malik@gmail.com>
Reviewed-by: Nisha Moond <nisha.moond412@gmail.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Dilip Kumar <dilipbalaut@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Discussion: https://postgr.es/m/OS0PR01MB5716BE80DAEB0EE2A6A5D1F5949D2@OS0PR01MB5716.jpnprd01.prod.outlook.com
2025-09-02 03:20:18 +00:00
Nathan Bossart
984d7165dd Document privileges required for vacuumdb --missing-stats-only.
When vacuumdb's --missing-stats-only option is used, the catalog
query for retrieving the list of relations to process must read
pg_statistic and pg_statistic_ext_data.  However, those catalogs
can only be read by superusers by default, so --missing-stats-only
is effectively superuser-only.  This is unfortunate, but since the
option is primarily intended for use by administrators after
running pg_upgrade, let's just live with it for v18.  This commit
adds a note about the aforementioned privilege requirements to the
documentation for --missing-stats-only.

We first tried to improve matters by modifying the query to read
the pg_stats and pg_stats_ext system views instead.  While that is
indeed more lenient from a privilege standpoint, it is also
borderline incomprehensible.  pg_stats shows rows for which the
user has the SELECT privilege on the corresponding column, and
pg_stats_ext shows rows for tables the user owns.  Meanwhile,
ANALYZE requires either MAINTAIN on the table or, for non-shared
relations, ownership of the database.  But even if the privilege
discrepancies were tolerable, the performance impact was not.
Ultimately, the modified query was substantially more expensive, so
we abandoned the idea.

For v19, perhaps we could introduce a simple, inexpensive way to
discover which relations are missing statistics, such as a system
function or view with similar privilege requirements to ANALYZE.
Unfortunately, it is far too late for anything like that in v18.

Reviewed-by: Yugo Nagata <nagata@sraoss.co.jp>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/CAHGQGwHh43suEfss1wvBsk7vqiou%3DUY0zcy8HGyE5hBp%2BHZ7SQ%40mail.gmail.com
Backpatch-through: 18
2025-08-26 14:49:01 -05:00
Fujii Masao
6429e5b771 vacuumdb: Make vacuumdb --analyze-only process partitioned tables.
vacuumdb should follow the behavior of the underlying VACUUM and ANALYZE
commands. When --analyze-only is used, it ought to analyze regular tables,
materialized views, and partitioned tables, just as ANALYZE (with no explicit
target tables) does. Otherwise, it should only process regular tables and
materialized views, since VACUUM skips partitioned tables when no targets
are given.

Previously, vacuumdb --analyze-only skipped partitioned tables. This was
inconsistent, and also inconvenient after pg_upgrade, where --analyze-only
is typically used to gather missing statistics.

This commit fixes the behavior so that vacuumdb --analyze-only also processes
partitioned tables. As a result, both vacuumdb --analyze-only and
ANALYZE (with no explicit targets) now analyze regular tables,
partitioned tables, and materialized views, but not foreign tables.

Because this is a nontrivial behavior change, it is applied only to master.

Reported-by: Zechman, Derek S <Derek.S.Zechman@snapon.com>
Author: Laurenz Albe <laurenz.albe@cybertec.at>
Co-authored-by: Mircea Cadariu <cadariu.mircea@gmail.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/CO1PR04MB8281387B9AD9DE30976966BBC045A%40CO1PR04MB8281.namprd04.prod.outlook.com
2025-08-20 13:16:06 +09:00
Nathan Bossart
71ea0d6795 Restrict psql meta-commands in plain-text dumps.
A malicious server could inject psql meta-commands into plain-text
dump output (i.e., scripts created with pg_dump --format=plain,
pg_dumpall, or pg_restore --file) that are run at restore time on
the machine running psql.  To fix, introduce a new "restricted"
mode in psql that blocks all meta-commands (except for \unrestrict
to exit the mode), and teach pg_dump, pg_dumpall, and pg_restore to
use this mode in plain-text dumps.

While at it, encourage users to only restore dumps generated from
trusted servers or to inspect it beforehand, since restoring causes
the destination to execute arbitrary code of the source superusers'
choice.  However, the client running the dump and restore needn't
trust the source or destination superusers.

Reported-by: Martin Rakhmanov
Reported-by: Matthieu Denais <litezeraw@gmail.com>
Reported-by: RyotaK <ryotak.mail@gmail.com>
Suggested-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Security: CVE-2025-8714
Backpatch-through: 13
2025-08-11 09:00:00 -05:00
Fujii Masao
0b6aea0384 doc: Recommend ANALYZE after ALTER TABLE ... SET EXPRESSION AS.
ALTER TABLE ... SET EXPRESSION AS removes statistics for the target column,
so running ANALYZE afterward is recommended. But this was previously not
documented, even though a similar recommendation exists for
ALTER TABLE ... SET DATA TYPE, which also clears the column's statistics.
This commit updates the documentation to include the ANALYZE recommendation
for SET EXPRESSION AS.

Since v18, virtual generated columns are supported, and these columns never
have statistics. Therefore, ANALYZE is not needed after SET DATA TYPE or
SET EXPRESSION AS when used on virtual generated columns. This commit also
updates the documentation to clarify that ANALYZE is unnecessary in such cases.

Back-patch the ANALYZE recommendation for SET EXPRESSION AS to v17
where the feature was introduced, and the note about virtual generated
columns to v18 where those columns were added.

Author: Yugo Nagata <nagata@sraoss.co.jp>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/20250804151418.0cf365bd2855d606763443fe@sraoss.co.jp
Backpatch-through: 17
2025-08-06 16:47:20 +09:00
Álvaro Herrera
126665289f
doc: mention unusability of dropped CHECK to verify NOT NULL
It's possible to use a CHECK (col IS NOT NULL) constraint to skip
scanning a table for nulls when adding a NOT NULL constraint on the same
column.  However, if the CHECK constraint is dropped on the same command
that the NOT NULL is added, this fails, i.e., makes the NOT NULL addition
slow.  The best we can do about it at this stage is to document this so
that users aren't taken by surprise.

(In Postgres 18 you can directly add the NOT NULL constraint as NOT
VALID instead, so there's no longer much use for the CHECK constraint,
therefore no point in building mechanism to support the case better.)

Reported-by: Andrew <psy2000usa@yahoo.com>
Reviewed-by: David G. Johnston <david.g.johnston@gmail.com>
Discussion: https://postgr.es/m/175385113607.786.16774570234342968908@wrigleys.postgresql.org
2025-08-04 13:26:45 +02:00
Amit Kapila
fd5a1a0c3e Detect and report update_deleted conflicts.
This enhancement builds upon the infrastructure introduced in commit
228c370868, which enables the preservation of deleted tuples and their
origin information on the subscriber. This capability is crucial for
handling concurrent transactions replicated from remote nodes.

The update introduces support for detecting update_deleted conflicts
during the application of update operations on the subscriber. When an
update operation fails to locate the target row-typically because it has
been concurrently deleted-we perform an additional table scan. This scan
uses the SnapshotAny mechanism and we do this additional scan only when
the retain_dead_tuples option is enabled for the relevant subscription.

The goal of this scan is to locate the most recently deleted tuple-matching
the old column values from the remote update-that has not yet been removed
by VACUUM and is still visible according to our slot (i.e., its deletion
is not older than conflict-detection-slot's xmin). If such a tuple is
found, the system reports an update_deleted conflict, including the origin
and transaction details responsible for the deletion.

This provides a groundwork for more robust and accurate conflict
resolution process, preventing unexpected behavior by correctly
identifying cases where a remote update clashes with a deletion from
another origin.

Author: Zhijie Hou <houzj.fnst@fujitsu.com>
Reviewed-by: shveta malik <shveta.malik@gmail.com>
Reviewed-by: Nisha Moond <nisha.moond412@gmail.com>
Reviewed-by: Dilip Kumar <dilipbalaut@gmail.com>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Discussion: https://postgr.es/m/OS0PR01MB5716BE80DAEB0EE2A6A5D1F5949D2@OS0PR01MB5716.jpnprd01.prod.outlook.com
2025-08-04 04:02:47 +00:00
Jeff Davis
6a46089e45 Simplify options in pg_dump and pg_restore.
Remove redundant options --with-data and --with-schema, and rename
--with-statistics to just --statistics.

Reviewed-by: Nathan Bossart <nathandbossart@gmail.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/f379d0aeefe8effe13302a436bc28f549f09e924.camel@j-davis.com
Backpatch-through: 18
2025-08-02 07:51:42 -07:00
Etsuro Fujita
37e7744585 Doc: clarify the restrictions of AFTER triggers with transition tables.
It was not very clear that the triggers are only allowed on plain tables
(not foreign tables).  Also, rephrase the documentation for better
readability.

Follow up to commit 9e6104c66.

Reported-by: Etsuro Fujita <etsuro.fujita@gmail.com>
Author: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Reviewed-by: Etsuro Fujita <etsuro.fujita@gmail.com>
Discussion: https://postgr.es/m/CAPmGK16XBs9ptNr8Lk4f-tJZogf6y-Prz%3D8yhvJbb_4dpsc3mQ%40mail.gmail.com
Backpatch-through: 13
2025-08-02 18:30:00 +09:00
Nathan Bossart
ee924698d5 doc: Adjust documentation for vacuumdb --missing-stats-only.
The sentence in question gave readers the impression that vacuumdb
removes statistics for a period of time while analyzing, but it's
actually meant to convey that --analyze-in-stages temporarily
replaces existing statistics with ones generated with lower
statistics targets.

Reported-by: Frédéric Yhuel <frederic.yhuel@dalibo.com>
Reviewed-by: Frédéric Yhuel <frederic.yhuel@dalibo.com>
Reviewed-by: "David G. Johnston" <david.g.johnston@gmail.com>
Reviewed-by: Corey Huinker <corey.huinker@gmail.com>
Reviewed-by: Jeff Davis <pgsql@j-davis.com>
Discussion: https://postgr.es/m/4b94ca16-7a6d-4581-b2aa-4ea79dbc082a%40dalibo.com
Backpatch-through: 18
2025-07-30 13:04:47 -05:00
Andrew Dunstan
ce9a6244b5 Revert Non text modes for pg_dumpall, and pg_restore support
Recent discussions of the mechanisms used to manage global data have
raised concerns about their robustness and security. Rather than try
to deal with those concerns at a very late stage of the release cycle,
the conclusion is to revert these features and work on them for the
next release.

This reverts parts or all of the following commits:

1495eff7bd Non text modes for pg_dumpall, correspondingly change pg_restore
5db3bf7391 Clean up from commit 1495eff7bd
289f74d0cb Add more TAP tests for pg_dumpall
2ef5790806 Fix a couple of error messages and tests for them
b52a4a5f28 Clean up error messages from 1495eff7bd
4170298b6e Further cleanup for directory creation on pg_dump/pg_dumpall
22cb6d2895 Fix memory leak in pg_restore.c
928394b664 Improve various new-to-v18 appendStringInfo calls
39729ec01d Fix fat fingering in 22cb6d2895
5822bf21d5 Add missing space in pg_restore documentation.
f09088a01d Free memory properly in pg_restore.c
40b9c27014 pg_restore cleanups
4aad2cb770 Portability fix: isdigit() must be passed an unsigned char.
88e947136b Fix typos and grammar in the code
f60420cff6 doc: Alphabetize long options for pg_dump[all].
bc35adee8d doc: Put new options in consistent order on man pages
a876464abc Message style improvements
dec6643487 Improve pg_dump/pg_dumpall help synopses and terminology
0ebd242555 Run pgperltidy

Discussion: https://postgr.es/m/20250708212819.09.nmisch@google.com

Backpatch-to: 18
Reviewed-by: Noah Misch <noah@leadboat.com>
2025-07-30 11:31:54 -04:00
Amit Kapila
228c370868 Preserve conflict-relevant data during logical replication.
Logical replication requires reliable conflict detection to maintain data
consistency across nodes. To achieve this, we must prevent premature
removal of tuples deleted by other origins and their associated commit_ts
data by VACUUM, which could otherwise lead to incorrect conflict reporting
and resolution.

This patch introduces a mechanism to retain deleted tuples on the
subscriber during the application of concurrent transactions from remote
nodes. Retaining these tuples allows us to correctly ignore concurrent
updates to the same tuple. Without this, an UPDATE might be misinterpreted
as an INSERT during resolutions due to the absence of the original tuple.

Additionally, we ensure that origin metadata is not prematurely removed by
vacuum freeze, which is essential for detecting update_origin_differs and
delete_origin_differs conflicts.

To support this, a new replication slot named pg_conflict_detection is
created and maintained by the launcher on the subscriber. Each apply
worker tracks its own non-removable transaction ID, which the launcher
aggregates to determine the appropriate xmin for the slot, thereby
retaining necessary tuples.

Conflict information retention (deleted tuples and commit_ts) can be
enabled per subscription via the retain_conflict_info option. This is
disabled by default to avoid unnecessary overhead for configurations that
do not require conflict resolution or logging.

During upgrades, if any subscription on the old cluster has
retain_conflict_info enabled, a conflict detection slot will be created to
protect relevant tuples from deletion when the new cluster starts.

This is a foundational work to correctly detect update_deleted conflict
which will be done in a follow-up patch.

Author: Zhijie Hou <houzj.fnst@fujitsu.com>
Reviewed-by: shveta malik <shveta.malik@gmail.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Dilip Kumar <dilipbalaut@gmail.com>
Reviewed-by: Nisha Moond <nisha.moond412@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Discussion: https://postgr.es/m/OS0PR01MB5716BE80DAEB0EE2A6A5D1F5949D2@OS0PR01MB5716.jpnprd01.prod.outlook.com
2025-07-23 02:56:00 +00:00
Fujii Masao
cb937e48f0 doc: Document reopen of output file via SIGHUP in pg_recvlogical.
When pg_recvlogical receives a SIGHUP signal, it closes the current
output file and reopens a new one. This is useful since it allows us to
rotate the output file by renaming the current file and sending a SIGHUP.

This behavior was previously undocumented. This commit adds
the missing documentation.

Back-patch to all supported versions.

Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Shinya Kato <shinya11.kato@gmail.com>
Discussion: https://postgr.es/m/0977fc4f-1523-4ecd-8a0e-391af4976367@oss.nttdata.com
Backpatch-through: 13
2025-07-20 11:58:31 +09:00