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
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
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
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
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
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
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
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
It looks like the example case was once modified to increase the number
of rows but the EXPLAIN ANALYZE output wasn't updated to reflect that.
Also adjust the text which discusses the index sizes. With the example
table size, the bloom index isn't quite 8 times more space efficient
than the btree indexes.
Discussion: https://postgr.es/m/CAApHDvovx8kQ0=HTt85gFDAwmTJHpCgiSvRmQZ_6u_g-vQYM_w@mail.gmail.com
Backpatch-through: 13, all supported versions
When using a pipeline, a transaction starts from the first command and
is committed with a Sync message or when the pipeline ends.
Functions like IsInTransactionBlock() or PreventInTransactionBlock()
were already able to understand a pipeline as being in a transaction
block, but it was not the case of CheckTransactionBlock(). This
function is called for example to generate a WARNING for SET LOCAL,
complaining that it is used outside of a transaction block.
The current state of the code caused multiple problems, like:
- SET LOCAL executed at any stage of a pipeline issued a WARNING, even
if the command was at least second in line where the pipeline is in a
transaction state.
- LOCK TABLE failed when invoked at any step of a pipeline, even if it
should be able to work within a transaction block.
The pipeline protocol assumes that the first command of a pipeline is
not part of a transaction block, and that any follow-up commands is
considered as within a transaction block.
This commit changes the backend so as an implicit transaction block is
started each time the first Execute message of a pipeline has finished
processing, with this implicit transaction block ended once a sync is
processed. The checks based on XACT_FLAGS_PIPELINING in the routines
checking if we are in a transaction block are not necessary: it is
enough to rely on the existing ones.
Some tests are added to pgbench, that can be backpatched down to v17
when \syncpipeline is involved and down to v14 where \startpipeline and
\endpipeline are available. This is unfortunately limited regarding the
error patterns that can be checked, but it provides coverage for various
pipeline combinations to check if these succeed or fail. These tests
are able to capture the case of SET LOCAL's WARNING. The author has
proposed a different feature to improve the coverage by adding similar
meta-commands to psql where error messages could be checked, something
more useful for the cases where commands cannot be used in transaction
blocks, like REINDEX CONCURRENTLY or VACUUM. This is considered as
future work for v18~.
Author: Anthonin Bonnefoy
Reviewed-by: Jelte Fennema-Nio, Michael Paquier
Discussion: https://postgr.es/m/CAO6_XqrWO8uNBQrSu5r6jh+vTGi5Oiyk4y8yXDORdE2jbzw8xw@mail.gmail.com
Backpatch-through: 13
Per PEP 3114, iterator.next() has been renamed to iterator.__next__(),
and one example in the documentation still used next(). This caused the
example provided to fail the function creation since Python 2 is not
supported anymore since 19252e8ec9.
Author: Erik Wienhold
Discussion: https://postgr.es/m/173209043143.2092749.13692266486972491694@wrigleys.postgresql.org
Backpatch-through: 15
