Small touch-up on commits 25505082f0 and 50fd428b2b. Fix the
formatting of the example messages in the documentation and adjust the
wording to match the code.
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
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
PostgreSQL always sends the BackendKeyData message at connection
startup, but there are some third party backend implementations out
there that don't support cancellation, and don't send the message
[1]. While the protocol docs left it up for interpretation if that is
valid behavior, libpq in PostgreSQL 17 and below accepted it. It does
not seem like the libpq behavior was intentional though, since it did
so by sending CancelRequest messages with all zeros to such servers
(instead of returning an error or making the cancel a no-op).
In version 18 the behavior was changed to return an error when trying
to create the cancel object with PGgetCancel() or PGcancelCreate().
This was done without any discussion, as part of supporting different
lengths of cancel packets for the new 3.2 version of the protocol.
This commit changes the behavior of PGgetCancel() / PGcancel() once
more to only return an error when the cancel object is actually used
to send a cancellation, instead of when merely creating the object.
The reason to do so is that some clients [2] create a cancel object as
part of their connection creation logic (thus having the cancel object
ready for later when they need it), so if creating the cancel object
returns an error, the whole connection attempt fails. By delaying the
error, such clients will still be able to connect to the third party
backend implementations in question, but when actually trying to
cancel a query, the user will be notified that that is not possible
for the server that they are connected to.
This commit only changes the behavior of the older PGgetCancel() /
PQcancel() functions, not the more modern PQcancelCreate() family of
functions. I.e. PQcancelCreate() returns a failed connection object
(CONNECTION_BAD) if the server didn't send a cancellation key. Unlike
the old PQgetCancel() function, we're not aware of any clients in the
field that use PQcancelCreate() during connection startup in a way
that would prevent connecting to such servers.
[1] AWS RDS Proxy is definitely one of them, and CockroachDB might be
another.
[2] psycopg2 (but not psycopg3).
Author: Jelte Fennema-Nio <postgres@jeltef.nl>
Reviewed-by: Jacob Champion <jacob.champion@enterprisedb.com>
Backpatch-through: 18
Discussion: https://www.postgresql.org/message-id/20250617.101056.1437027795118961504.ishii%40postgresql.org
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 1495eff7bd289f74d0cb Add more TAP tests for pg_dumpall
2ef5790806 Fix a couple of error messages and tests for them
b52a4a5f28 Clean up error messages from 1495eff7bd4170298b6e 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 22cb6d28955822bf21d5 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>
This commit adds missing index entries for the functions pg_buffercache_numa()
and pg_buffercache_usage_counts() in the pg_buffercache documentation.
It also makes the function titles consistent by adding parentheses after
function names where they were previously missing.
Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/7d19af4b-7da3-4862-9f52-ff958960bd8d@oss.nttdata.com
Backpatch-through: 18
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
This commit adds a note to the pg_overexplain page that describes
how to use it (LOAD, session_preload_libraries, or
shared_preload_libraries). The new text is mostly lifted from the
auto_explain page. We should probably consider centralizing this
information in the future.
While at it, add a missing "module" to the opening sentence.
Reviewed-by: "David G. Johnston" <david.g.johnston@gmail.com>
Reviewed-by: Robert Treat <rob@xzilla.net>
Reviewed-by: Dean Rasheed <dean.a.rasheed@gmail.com>
Discussion: https://postgr.es/m/aHVWKM8l8kLlZzgv%40nathan
Backpatch-through: 18
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
Previously, the documentation described the streaming option as a boolean,
which is outdated since it's no longer a boolean as of protocol version 4.
This could confuse users.
This commit updates the description to remove the "boolean" reference and
clearly list the valid values for the streaming option.
Back-patch to v16, where the streaming option changed to a non-boolean.
Author: Euler Taveira <euler@eulerto.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/8d21fb98-5c25-4dee-8387-e5a62b01ea7d@app.fastmail.com
Backpatch-through: 16
The last_vacuum and vacuum_count fields in pg_stat_all_tables already
state that they do not include VACUUM FULL. However, total_vacuum_time,
which also excludes VACUUM FULL, did not mention this. This could
mislead users into thinking VACUUM FULL time is included.
To address this, this commit updates the documentation for
pg_stat_all_tables to explicitly state that total_vacuum_time does not
count VACUUM FULL.
Back-patched to v18, where total_vacuum_time was introduced.
Additionally, this commit clarifies that n_ins_since_vacuum also
excludes VACUUM FULL. Although n_ins_since_vacuum was added in v13,
we are not back-patching this change to stable branches, as it is
a documentation improvement, not a bug fix.
Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Robert Treat <rob@xzilla.net>
Reviewed-by: David G. Johnston <david.g.johnston@gmail.com>
Reviewed-by: Laurenz Albe <laurenz.albe@cybertec.at>
Discussion: https://postgr.es/m/2ac375d1-591b-4f1b-a2af-f24335567866@oss.nttdata.com
Backpatch-through: 18
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
Previously, the idle_replication_slot_timeout parameter used minutes
as its unit, based on the assumption that values would typically exceed
one minute in production environments. However, this caused unexpected
behavior: specifying a value below 30 seconds would round down to 0,
effectively disabling the timeout. This could be surprising to users.
To allow finer-grained control and avoid such confusion, this commit changes
the unit of idle_replication_slot_timeout to seconds. Larger values can
still be specified easily using standard time suffixes, for example,
'24h' for 24 hours.
Back-patch to v18 where idle_replication_slot_timeout was added.
Reported-by: Gunnar Morling <gunnar.morling@googlemail.com>
Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Laurenz Albe <laurenz.albe@cybertec.at>
Reviewed-by: David G. Johnston <david.g.johnston@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CADGJaX_0+FTguWpNSpgVWYQP_7MhoO0D8=cp4XozSQgaZ40Odw@mail.gmail.com
Backpatch-through: 18
This routine has been introduced as a shortcut to be able to retrieve a
service name from an active connection, for psql. Per discussion, and
as it is only used by psql, let's remove it to not clutter the libpq API
more than necessary.
The logic in psql is replaced by lookups of PQconninfoOption for the
active connection, instead, updated each time the variables are synced
by psql, the prompt shortcut relying on the variable synced.
Reported-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/20250706161319.c1.nmisch@google.com
Backpatch-through: 18
The documentation for pg_replication_slots previously mentioned only
max_slot_wal_keep_size as a condition under which the wal_status column
could show unreserved or lost. However, since commit be87200,
replication slots can also be invalidated due to horizon or wal_level,
and since commit ac0e33136a, idle_replication_slot_timeout can also
trigger this state.
This commit updates the description of the wal_status column to
reflect that max_slot_wal_keep_size is not the only cause of the lost state.
Back-patched to v16, where the additional invalidation cases were introduced.
Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Nisha Moond <nisha.moond412@gmail.com>
Discussion: https://postgr.es/m/78b34e84-2195-4f28-a151-5d204a382fdd@oss.nttdata.com
Backpatch-through: 16
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
Commit 1546e17f9d accidentally misspelled additionally as
additionaly. Backpatch to v17 to match where the original
commit was backpatched.
Author: Daniel Gustafsson <daniel@yesql.se>
Backpatch-through: 17
This commit renames the pg_recvlogical options --two-phase and
--failover to --enable-two-phase and --enable-failover, respectively.
The new names distinguish these enabling options from action options
like --start and --create-slot, while clearly indicating their purpose
to enable specific logical slot features.
The option --failover is new in PostgreSQL 18 (commit cf2655a902), so
no compatibility break there. The option --two-phase has existed
since PostgreSQL 15 (commit cda03cfed6), so for compatibility we keep
the old option name --two-phase around as deprecated.
Also note that pg_createsubscriber has acquired an --enable-two-phase
option, so this increases consistency across tools.
Co-authored-by: Masahiko Sawada <sawada.mshk@gmail.com>
Discussion: https://postgr.es/m/a28f66df-1354-4709-8d63-932ded4cac35@eisentraut.org
Just like selecting from a view is exploitable (CVE-2024-7348),
selecting from a table with virtual generated columns is exploitable.
Users who are concerned about this can avoid selecting from views, but
telling them to avoid selecting from tables is less practical.
To address this, this changes it so that generation expressions for
virtual generated columns are restricted to using built-in functions
and types, and the columns are restricted to having a built-in type.
We assume that built-in functions and types cannot be exploited for
this purpose.
In the future, this could be expanded by some new mechanism to declare
other functions and types as safe or trusted for this purpose, but
that is to be designed.
(An alternative approach might have been to expand the
restrict_nonsystem_relation_kind GUC to handle this, like the fix for
CVE-2024-7348. But that is kind of an ugly approach. That fix had to
fit in the constraints of fixing an ancient vulnerability in all
branches. Since virtual generated columns are new, we're free from
the constraints of the past, and we can and should use cleaner
options.)
Reported-by: Feike Steenbergen <feikesteenbergen@gmail.com>
Reviewed-by: jian he <jian.universality@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/CAK_s-G2Q7de8Q0qOYUR%3D_CTB5FzzVBm5iZjOp%2BmeVWpMpmfO0w%40mail.gmail.com
Protocol v4 introduces parallel streaming, which allows Stream Abort
messages to include additional abort information such as LSN and
timestamp. However, the current documentation only states, "This field is
available since protocol version 4," which may misleadingly suggest that
the fields are always present when using protocol v4.
This patch clarifies that the abort LSN and timestamp are included only
when parallel streaming is enabled, even under protocol v4.
Author: Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Backpatch-through: 16, where it was introduced
Discussion: https://postgr.es/m/CAO6_XqoKteQR1AnaR8iPcegbBE+HkAc2-g12rxN04yOt4-2ORg@mail.gmail.com
The documentation previously described the type of the io_workers GUC
parameter as "int". However, the documentation consistently uses "integer"
for parameters of this type.
This commit updates the type description of io_workers to "integer"
for consistency with other GUC parameter descriptions.
Author: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/e95c899a-2aeb-45b7-8fd3-7a27dcdb475b@oss.nttdata.com
The documentation for track_cost_delay_timing describes where cost-based
vacuum delay timing information is displayed when the setting is enabled.
While this information is also shown in the output of ANALYZE VERBOSE,
that was previously omitted from the list.
This commit updates the documentation to include ANALYZE VERBOSE in the list,
clarifying that it also reports cost-based delay timing information.
Author: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/e95c899a-2aeb-45b7-8fd3-7a27dcdb475b@oss.nttdata.com
For parameters that exist as both configuration and storage options,
the documentation typically includes secondary index entries to
help users distinguish and locate the relevant references easily.
However, such index entries were missing for vacuum_truncate and
vacuum_max_eager_freeze_failure_rate, both introduced in v18.
This commit adds appropriate secondary index terms for these parameters
to ensure consistency with other parameters and improve usability of
the documentation index.
Author: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/e95c899a-2aeb-45b7-8fd3-7a27dcdb475b@oss.nttdata.com
