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
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
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
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
Although the "Floating-Point Types" section says that "float" data
type is taken to mean "double precision", this information was not
reflected in the data type table that lists all data type aliases.
Reported-by: alexander.kjall@hafslund.no
Author: Euler Taveira <euler@eulerto.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/175456294638.800.12038559679827947313@wrigleys.postgresql.org
Backpatch-through: 13
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
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
This commit documents differences in the definition of word separators for
the initcap function between libc and ICU locale providers.
Backpatch to all supported branches.
Discussion: https://postgr.es/m/804cc10ef95d4d3b298e76b181fd9437%40postgrespro.ru
Author: Oleg Tselebrovskiy <o.tselebrovskiy@postgrespro.ru>
Backpatch-through: 13
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
The paragraph for introducing INSERT and COPY discussed how a file
could be used for bulk loading with COPY, without actually showing
what the file would look like. This adds a programlisting for the
file contents.
Backpatch to all supported branches since this example has lacked
the file contents since PostgreSQL 7.2.
Author: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Fujii Masao <masao.fujii@oss.nttdata.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/158017814191.19852.15019251381150731439@wrigleys.postgresql.org
Backpatch-through: 13
The grammar was a little shaky and confusing here, so word-smith it
a bit. Also, adjust the comments in pg_ident.conf.sample to use the
same terminology as the SGML docs, in particular "DATABASE-USERNAME"
not "PG-USERNAME".
Back-patch appropriate subsets. I did not risk changing
pg_ident.conf.sample in released branches, but it still seems OK
to change it in v18.
Reported-by: Alexey Shishkin <alexey.shishkin@enterprisedb.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: David G. Johnston <david.g.johnston@gmail.com>
Discussion: https://postgr.es/m/175206279327.3157504.12519088928605422253@wrigleys.postgresql.org
Backpatch-through: 13
Minor wordsmithing of the func.sgml paragraph describing
statement_timestamp() and allied functions: don't switch between
"statement" and "command" when those are being used to mean about
the same thing.
Also, add some text to protocol.sgml describing the perhaps-surprising
behavior these functions have in a multi-statement Query message.
Reported-by: P M <petermittere@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Laurenz Albe <laurenz.albe@cybertec.at>
Reviewed-by: David G. Johnston <david.g.johnston@gmail.com>
Discussion: https://postgr.es/m/175223006802.3157505.14764328206246105568@wrigleys.postgresql.org
Backpatch-through: 13
The documentation previously stated that the wal_status column is NULL
if restart_lsn is NULL in the pg_replication_slots view. This is incorrect,
and wal_status can be "lost" even when restart_lsn is NULL.
This commit removes the incorrect description.
Back-patched to all supported versions.
Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Nisha Moond <nisha.moond412@gmail.com>
Discussion: https://postgr.es/m/c9d23cdc-b5dd-455a-8ee9-f1f24d701d89@oss.nttdata.com
Backpatch-through: 13
These functions have been around for some time, but commits
48b5aa3143 and 15afb7d61c were only back-patched to v16. Let's
back-patch them to all supported versions now.
Reported-by: David Rowley <dgrowleyml@gmail.com> (commit 48b5aa3143)
Author: Bruce Momjian <bruce@momjian.us> (commit 48b5aa3143)
Co-authored-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com> (commit 15afb7d61c)
Reviewed-by: Michael Paquier <michael@paquier.xyz> (commit 15afb7d61c)
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: Álvaro Herrera <alvherre@kurilemu.de>
Discussion: https://postgr.es/m/aGMCxHxLfeMdQk8m%40nathan
Backpatch-through: 13-15
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
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
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
The documentation for the pg_authid system catalog and the
pg_shadow system view indicates that passwords might be stored in
cleartext, but that hasn't been possible for some time.
Oversight in commit eb61136dc7.
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/aD2yKkZro4nbl5ol%40nathan
Backpatch-through: 13
Commits 53af9491a0 and 2d5fe51405 fixed a number of problems with
foreign keys that reference partitioned tables, and a query to detect
already broken FKs was supplied with the release notes for 17.1, 16.5,
15.9, 14.14, 13.17. However, that query has a bug that causes it to
wrongly report self-referential foreign keys even when they are correct,
so if the user was to drop and rebuild the FKs as indicated, the query
would continue to report them as needing to be repaired. Here we fix
the query to not have that problem.
Reported-by: Paul Foerster <paul.foerster@gmail.com>
Discussion: https://postgr.es/m/5456A1D0-CD47-4315-9C65-71B27E7A2906@gmail.com
Backpatch-through: 13-17
The documentation for exported snapshots in logical decoding previously
stated that snapshot creation may fail on a hot standby. This is no longer
accurate, as snapshot exporting on standbys has been supported since
PostgreSQL 10. This commit removes the outdated description.
Additionally, the docs referred to the NOEXPORT_SNAPSHOT option to
suppress snapshot exporting in CREATE_REPLICATION_SLOT. However,
since PostgreSQL 15, NOEXPORT_SNAPSHOT is considered legacy syntax
and retained only for backward compatibility. This commit updates
the documentation for v15 and later to use the modern equivalent:
SNAPSHOT 'nothing'. The older syntax is preserved in documentation for
v14 and earlier.
Back-patched to all supported branches.
Reported-by: Kevin K Biju <kevinkbiju@gmail.com>
Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Kevin K Biju <kevinkbiju@gmail.com>
Discussion: https://postgr.es/m/174791480466.798.17122832105389395178@wrigleys.postgresql.org
Backpatch-through: 13
Invalid indexes are suffixed with "_ccnew" or "_ccold". The
documentation missed to mention the initial underscore.
ChooseRelationName() may also append an extra number if indexes with a
similar name already exist; let's add a note about that too.
Author: Alec Cozens <acozens@pixelpower.com>
Discussion: https://postgr.es/m/174733277404.1455388.11471370288789479593@wrigleys.postgresql.org
Backpatch-through: 13
This aligns the copyright and legal notice wordig with commit
a233a603ba and pgweb commit 2d764dbc083ab8. Backpatch down
to all supported versions.
Author: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Dave Page <dpage@pgadmin.org>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/744E414E-3F52-404C-97FB-ED9B3AA37DC8@yesql.se
Backpatch-through: 13
SQL "SET search_path = 'pg_catalog, pg_temp'" is silently equivalent to
"SET search_path = pg_temp, pg_catalog, "pg_catalog, pg_temp"" instead
of the intended "SET search_path = pg_catalog, pg_temp". (The intent
was a two-element search path. With the single quotes, it instead
specifies one element with a comma and a space in the middle of the
element.) In addition to the SET statement, this affects SET clauses of
CREATE FUNCTION, ALTER ROLE, and ALTER DATABASE. It does not affect the
set_config() SQL function.
Though the documentation did not show an insecure command, remove single
quotes that could entice a reader to write an insecure command.
Back-patch to v13 (all supported versions).
Reported-by: Sven Klemm <sven@timescale.com>
Author: Sven Klemm <sven@timescale.com>
Backpatch-through: 13
Add a documentation warning to ts_headline() pointing out that, when
working with untrusted input documents, the output is not guaranteed
to be safe for direct inclusion in web pages. This is because, while
it does remove some XML tags from the input, it doesn't remove all
HTML markup, and so the result may be unsafe (e.g., it might permit
XSS attacks).
To guard against that, all HTML markup should be removed from the
input, making it plain text, or the output should be passed through an
HTML sanitizer.
In addition, document precisely what the default text search parser
recognises as valid XML tags, since that's what determines which XML
tags ts_headline() will remove.
Reported-by: Richard Neill <richard.neill@telos.digital>
Author: Dean Rasheed <dean.a.rasheed@gmail.com>
Reviewed-by: Noah Misch <noah@leadboat.com>
Backpatch-through: 13
It's been twenty years since we generated constraint names that
look like "$N". So this advice about double-quoting such names
is well past its sell-by date, and now it merely seems confusing.
Reported-by: Yaroslav Saburov <y.saburov@gmail.com>
Author: "David G. Johnston" <david.g.johnston@gmail.com>
Discussion: https://postgr.es/m/174393459040.678.17810152410419444783@wrigleys.postgresql.org
Backpatch-through: 13
Clarify the project naming in the history section of the docs
to match the recent license preamble changes.
Backpatch to all supported versions.
Author: Dave Page <dpage@pgadmin.org>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://postgr.es/m/CA+OCxozLzK2+Jc14XZyWXSp6L9Ot+3efwXUE35FJG=fsbib2EA@mail.gmail.com
Backpatch-through: 13
The implementation of FSM for indexes is simpler than heap, where 0 is
used to track if a page is in-use and (BLCKSZ - 1) if a page is free.
One comment in indexfsm.c and one description in the documentation of
pg_freespacemap were incorrect about that.
Author: Alex Friedman <alexf01@gmail.com>
Discussion: https://postgr.es/m/71eef655-c192-453f-ac45-2772fec2cb04@gmail.com
Backpatch-through: 13
pg_drop_replication_slot() can drop replication slots created on
a different database than the one where it is executed. This behavior
has been in place since PostgreSQL 9.4, when pg_drop_replication_slot()
was introduced.
However, commit ff539d mistakenly added the following incorrect
description in the documentation:
For logical slots, this must be called when connected to
the same database the slot was created on.
This commit removes that incorrect statement. A similar mistake was
also present in the documentation for the DROP_REPLICATION_SLOT
command, which has now been corrected as well.
Back-patch to all supported versions.
Author: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/OSCPR01MB14966C6BE304B5BB2E58D4009F5DE2@OSCPR01MB14966.jpnprd01.prod.outlook.com
Backpatch-through: 13
The previous wording talked about a "single pass over the data",
which can be read as promising more than intended (to wit, that only
one WindowAgg plan node will be used). What we promise is only what
the SQL spec requires, namely that the data not get re-sorted between
window functions with compatible PARTITION BY/ORDER BY clauses.
Adjust the wording in hopes of making this clearer.
Reported-by: Christopher Inokuchi <cinokuchi@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: David G. Johnston <david.g.johnston@gmail.com>
Discussion: https://postgr.es/m/CABde6B5va2wMsnM79u_x=n9KUgfKQje_pbLROEBmA9Ru5XWidw@mail.gmail.com
Backpatch-through: 13
The threshold is two billion members, which was interpreted as 2GB
in the documentation. Fix to reflect that each member takes up five
bytes, which translates to about 10GB. This is not exact, because of
page boundaries. While at it, mention the maximum size 20GB.
This has been wrong since commit c552e171d1, so backpatch to
version 14.
Author: Alex Friedman <alexf01@gmail.com>
Reviewed-by: Sami Imseih <samimseih@gmail.com>
Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://postgr.es/m/CACbFw60UOk6fCC02KsyT3OfU9Dnuq5roYxdw2aFisiN_p1L0bg@mail.gmail.com
Backpatch-through: 14
Try to make it absolutely plain that we don't retain the
originally specified time zone, only the UTC timestamp.
While at it, make glossary entries for "UTC" and "GMT".
Author: Robert Treat <rob@xzilla.net>
Co-authored-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/173796426022.1064.9135167366862649513@wrigleys.postgresql.org
Backpatch-through: 13
Two links in the isn module documentation were pointing to tools
which had been moved, resulting in 404 error responses. Update
to the new URLs for the tools. The link to the Sequoia 2000 page
in the history section was no longer working, and since the page
is no longer available online update our link to point at the
paper instead which is on a stable URL.
These links exist in all versions of the documentation so backpatch
to all supported branches.
Author: Daniel Gustafsson <daniel@yesql.se>
Reported-by: charukiewicz@protonmail.com
Discussion: https://postgr.es/m/173679670185.705.8565555804465055355@wrigleys.postgresql.org
Backpatch-through: 13
This practice avoids possible problems caused by non-default psql
options, such as disabling AUTOCOMMIT.
Author: Shinya Kato <Shinya11.Kato@oss.nttdata.com>
Reviewed-by: Robert Treat <rob@xzilla.net>
Discussion: https://postgr.es/m/96ff23a5d858ff72ca8e823a014d16fe@oss.nttdata.com
Backpatch-through: 13
Slightly faulty logic in the original jsonb code (commit d9134d0a35)
results in an empty top level array sorting less than a json null. We
can't change the sort order now since it would affect btree indexes over
jsonb, so document the anomaly.
Backpatch to all live branches (13 .. 17)
In master, also add a code comment noting the anomaly.
Reported-by: Yan Chengpen
Reviewed-by: Jian He
Discussion: https://postgr.es/m/OSBPR01MB45199DD8DA2D1CECD50518188E272@OSBPR01MB4519.jpnprd01.prod.outlook.com
David Rowley