The last section of pg_createsubscriber used the terms
"publication-name", "replication-slot-name", and "subscription-name".
These terms are not defined on the page, which was confusing, and the
intention is clearly to refer to the values one would give to the
options --publication, --subscription and --replication-slot. Let's
simplify the documentation by mentioning the option switches, instead of
these terms.
Reported-by: Christophe Courtois
Author: Shubham Khanna
Reviewed-by: Vignesh C, Peter Smith
Discussion: https://postgr.es/m/173288198026.714.15127074046508836738@wrigleys.postgresql.org
Backpatch-through: 17
MD5 has been considered to be unsuitable for use as a cryptographic
hash algorithm for some time. Furthermore, MD5 password hashes in
PostgreSQL are vulnerable to pass-the-hash attacks, i.e., knowing
the username and hashed password is sufficient to authenticate.
The SCRAM-SHA-256 method added in v10 is not subject to these
problems and is considered to be superior to MD5.
This commit marks MD5 password support in PostgreSQL as deprecated
and to be removed in a future release. The documentation now
contains several deprecation notices, and CREATE ROLE and ALTER
ROLE now emit deprecation warnings when setting MD5 passwords. The
warnings can be disabled by setting the md5_password_warnings
parameter to "off".
Reviewed-by: Greg Sabino Mullane, Jim Nasby
Discussion: https://postgr.es/m/ZwbfpJJol7lDWajL%40nathan
Historically we tolerated the absence of various C runtime library
features for the benefit of the MinGW tool chain, because it used
ancient msvcrt.dll for a long period of time. It now uses ucrt by
default (like Windows 10+, Visual Studio 2015+), and that's the only
configuration we're testing.
In practice, we effectively required ucrt already in PostgreSQL 17, when
commit 8d9a9f03 required _create_locale etc, first available in
msvcr120.dll (Visual Studio 2013, the last of the pre-ucrt series of
runtimes), and for MinGW users that practically meant ucrt because it
was difficult or impossible to use msvcr120.dll. That may even not have
been the first such case, but old MinGW configurations had already
dropped off our testing radar so we weren't paying much attention.
This commit formalizes the requirement. It also removes a couple of
obsolete comments that discussed msvcrt.dll limitations, and some tests
of !defined(_MSC_VER) to imply msvcrt.dll. There are many more
anachronisms, but it'll take some time to figure out how to remove them
all. APIs affected relate to locales, UTF-8, threads, large files and
more.
Thanks to Peter Eisentraut for the documentation change. It's not
really necessary to talk about ucrt explicitly in such a short section,
since it's the default for MinGW-w64 and MSYS2. It's enough to prune
references and broken links to much older tools.
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://postgr.es/m/d9e7731c-ca1b-477c-9298-fa51e135574a%40eisentraut.org
This allows for example using LIKE with case-insensitive collations.
There was previously no internal implementation of this, so it was met
with a not-supported error. This adds the internal implementation and
removes the error. The implementation follows the specification of
the SQL standard for this.
Unlike with deterministic collations, the LIKE matching cannot go
character by character but has to go substring by substring. For
example, if we are matching against LIKE 'foo%bar', we can't start by
looking for an 'f', then an 'o', but instead with have to find
something that matches 'foo'. This is because the collation could
consider substrings of different lengths to be equal. This is all
internal to MatchText() in like_match.c.
The changes in GenericMatchText() in like.c just pass through the
locale information to MatchText(), which was previously not needed.
This matches exactly Generic_Text_IC_like() below.
ILIKE is not affected. (It's unclear whether ILIKE makes sense under
nondeterministic collations.)
This also updates match_pattern_prefix() in like_support.c to support
optimizing the case of an exact pattern with nondeterministic
collations. This was already alluded to in the previous code.
(includes documentation examples from Daniel Vérité and test cases
from Paul A Jungwirth)
Reviewed-by: Jian He <jian.universality@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/700d2e86-bf75-4607-9cf2-f5b7802f6e88@eisentraut.org
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
In commit 641a5b7a14, I removed "nbsp" characters from SVG files, not
realizing the SVG files were generated from GV files and that the "nbsp"
characters were caused by trailing ASCII spaces in GV files. This
commit restores the "nbsp" SVG characters and adds a GV comment about
how the trailing spaces cause the "nbsp" output.
Reported-by: Peter Eisentraut
Discussion: https://postgr.es/m/2c5dd601-b245-4092-9c27-6d1ad51609df%40eisentraut.org
Backpatch-through: master
The ordering of DISTINCT items is semantically insignificant, so we
can reorder them as needed. In fact, in the parser, we absorb the
sorting semantics of the sortClause as much as possible into the
distinctClause, ensuring that one clause is a prefix of the other.
This can help avoid a possible need to re-sort.
In this commit, we attempt to adjust the DISTINCT keys to match the
input path's pathkeys. This can likewise help avoid re-sorting, or
allow us to use incremental-sort to save efforts.
For DISTINCT ON expressions, the parser already ensures that they
match the initial ORDER BY expressions. When reordering the DISTINCT
keys, we must ensure that the resulting pathkey list matches the
initial distinctClause pathkeys.
This introduces a new GUC, enable_distinct_reordering, which allows
the optimization to be disabled if needed.
Author: Richard Guo
Reviewed-by: Andrei Lepikhov
Discussion: https://postgr.es/m/CAMbWs48dR26cCcX0f=8bja2JKQPcU64136kHk=xekHT9xschiQ@mail.gmail.com
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
Commit 4ac2a9bece introduced the REJECT_LIMIT option for the COPY
command. This commit extends the support for this option to file_fdw.
As well as REJECT_LIMIT option for COPY, this option limits
the maximum number of erroneous rows that can be skipped.
If the number of data type conversion errors exceeds this limit,
accessing the file_fdw foreign table will fail with an error,
even when on_error = 'ignore' is specified.
Since the CREATE/ALTER FOREIGN TABLE commands require foreign
table options to be single-quoted, this commit updates
defGetCopyRejectLimitOption() to handle also string value for them,
in addition to int64 value for COPY command option.
Author: Atsushi Torikoshi
Reviewed-by: Fujii Masao, Yugo Nagata, Kirill Reshke
Discussion: https://postgr.es/m/bab68a9fc502b12693f0755b6f35f327@oss.nttdata.com
Previously, database object statistics manipulation functions like
pg_set_relation_stats() reported unclear error and hint messages
when executed during recovery. These messages were "internal",
making it difficult for users to understand the issue:
ERROR: cannot acquire lock mode ShareUpdateExclusiveLock on database objects while recovery is in progress
HINT: Only RowExclusiveLock or less can be acquired on database objects during recovery.
This commit updates the error handling so that, if these functions
are called during recovery, they produce clearer messages:
ERROR: recovery is in progress
HINT: Statistics cannot be modified during recovery.
The related documentation has also been updated to explicitly
clarify that these functions are not available during recovery.
Author: Fujii Masao
Reviewed-by: Heikki Linnakangas, Maxim Orlov
Discussion: https://postgr.es/m/6d313829-5f56-4a28-ae4b-bd01bf1ae791@oss.nttdata.com
Allowing foreign keys where the referenced and the referencing columns
have collations with different notions of equality is problematic.
This can only happen when using nondeterministic collations, for
example, if the referencing column is case-insensitive and the
referenced column is not, or vice versa. It does not happen if both
collations are deterministic.
To show one example:
CREATE COLLATION case_insensitive (provider = icu, deterministic = false, locale = 'und-u-ks-level2');
CREATE TABLE pktable (x text COLLATE "C" PRIMARY KEY);
CREATE TABLE fktable (x text COLLATE case_insensitive REFERENCES pktable ON UPDATE CASCADE ON DELETE CASCADE);
INSERT INTO pktable VALUES ('A'), ('a');
INSERT INTO fktable VALUES ('A');
BEGIN; DELETE FROM pktable WHERE x = 'a'; TABLE fktable; ROLLBACK;
BEGIN; DELETE FROM pktable WHERE x = 'A'; TABLE fktable; ROLLBACK;
Both of these DELETE statements delete the one row from fktable. So
this means that one row from fktable references two rows in pktable,
which should not happen. (That's why a primary key or unique
constraint is required on pktable.)
When nondeterministic collations were implemented, the SQL standard
available to yours truly said that referential integrity checks should
be performed with the collation of the referenced column, and so
that's how we implemented it. But this turned out to be a mistake in
the SQL standard, for the same reasons as above, that was later
(SQL:2016) fixed to require both collations to be the same. So that's
what we are aiming for here.
We don't have to be quite so strict. We can allow different
collations if they are both deterministic. This is also good for
backward compatibility.
So the new rule is that the collations either have to be the same or
both deterministic. Or in other words, if one of them is
nondeterministic, then both have to be the same.
Users upgrading from before that have affected setups will need to
make changes to their schemas (i.e., change one or both collations in
affected foreign-key relationships) before the upgrade will succeed.
Some of the nice test cases for the previous situation in
collate.icu.utf8.sql are now obsolete. They are changed to just check
the error checking of the new rule. Note that collate.sql already
contained a test for foreign keys with different deterministic
collations.
A bunch of code in ri_triggers.c that added a COLLATE clause to
enforce the referenced column's collation can be removed, because both
columns now have to have the same notion of equality, so it doesn't
matter which one to use.
Reported-by: Paul Jungwirth <pj@illuminatedcomputing.com>
Reviewed-by: Jian He <jian.universality@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/78d824e0-b21e-480d-a252-e4b84bc2c24b@illuminatedcomputing.com
Many process environment variables (e.g. PATH), bypass the containment
expected of a trusted PL. Hence, trusted PLs must not offer features
that achieve setenv(). Otherwise, an attacker having USAGE privilege on
the language often can achieve arbitrary code execution, even if the
attacker lacks a database server operating system user.
To fix PL/Perl, replace trusted PL/Perl %ENV with a tied hash that just
replaces each modification attempt with a warning. Sites that reach
these warnings should evaluate the application-specific implications of
proceeding without the environment modification:
Can the application reasonably proceed without the modification?
If no, switch to plperlu or another approach.
If yes, the application should change the code to stop attempting
environment modifications. If that's too difficult, add "untie
%main::ENV" in any code executed before the warning. For example,
one might add it to the start of the affected function or even to
the plperl.on_plperl_init setting.
In passing, link to Perl's guidance about the Perl features behind the
security posture of PL/Perl.
Back-patch to v12 (all supported versions).
Andrew Dunstan and Noah Misch
Security: CVE-2024-10979
The GUC max_replication_slots has a different meaning for sending servers
and subscribers. Add cross-links in each section for easy reference.
Author: Tristan Partin
Discussion: https://postgr.es/m/D5FNEPMMFHFX.1OQBCML0TU5AH@partin.io
Two attributes are added to pg_stat_database:
* parallel_workers_to_launch, counting the total number of parallel
workers that were planned to be launched.
* parallel_workers_launched, counting the total number of parallel
workers actually launched.
The ratio of both fields can provide hints that there are not enough
slots available when launching parallel workers, also useful when
pg_stat_statements is not deployed on an instance (i.e. cf54a2c002).
This commit relies on de3a2ea3b2, that has added two fields to EState,
that get incremented when executing Gather or GatherMerge nodes.
A test is added in select_parallel, where parallel workers are spawned.
Bump catalog version.
Author: Benoit Lobréau
Discussion: https://postgr.es/m/783bc7f7-659a-42fa-99dd-ee0565644e25@dalibo.com
This commit changes libpq so that errors reported by the backend during
the protocol negotiation for SSL and GSS are discarded by the client, as
these may include bytes that could be consumed by the client and write
arbitrary bytes to a client's terminal.
A failure with the SSL negotiation now leads to an error immediately
reported, without a retry on any other methods allowed, like a fallback
to a plaintext connection.
A failure with GSS discards the error message received, and we allow a
fallback as it may be possible that the error is caused by a connection
attempt with a pre-11 server, GSS encryption having been introduced in
v12. This was a problem only with v17 and newer versions; older
versions discard the error message already in this case, assuming a
failure caused by a lack of support for GSS encryption.
Author: Jacob Champion
Reviewed-by: Peter Eisentraut, Heikki Linnakangas, Michael Paquier
Security: CVE-2024-10977
Backpatch-through: 12
We now create contype='n' pg_constraint rows for not-null constraints on
user tables. Only one such constraint is allowed for a column.
We propagate these constraints to other tables during operations such as
adding inheritance relationships, creating and attaching partitions and
creating tables LIKE other tables. These related constraints mostly
follow the well-known rules of conislocal and coninhcount that we have
for CHECK constraints, with some adaptations: for example, as opposed to
CHECK constraints, we don't match not-null ones by name when descending
a hierarchy to alter or remove it, instead matching by the name of the
column that they apply to. This means we don't require the constraint
names to be identical across a hierarchy.
The inheritance status of these constraints can be controlled: now we
can be sure that if a parent table has one, then all children will have
it as well. They can optionally be marked NO INHERIT, and then children
are free not to have one. (There's currently no support for altering a
NO INHERIT constraint into inheriting down the hierarchy, but that's a
desirable future feature.)
This also opens the door for having these constraints be marked NOT
VALID, as well as allowing UNIQUE+NOT NULL to be used for functional
dependency determination, as envisioned by commit e49ae8d3bc. It's
likely possible to allow DEFERRABLE constraints as followup work, as
well.
psql shows these constraints in \d+, though we may want to reconsider if
this turns out to be too noisy. Earlier versions of this patch hid
constraints that were on the same columns of the primary key, but I'm
not sure that that's very useful. If clutter is a problem, we might be
better off inventing a new \d++ command and not showing the constraints
in \d+.
For now, we omit these constraints on system catalog columns, because
they're unlikely to achieve anything.
The main difference to the previous attempt at this (b0e96f3119) is
that we now require that such a constraint always exists when a primary
key is in the column; we didn't require this previously which had a
number of unpalatable consequences. With this requirement, the code is
easier to reason about. For example:
- We no longer have "throwaway constraints" during pg_dump. We needed
those for the case where a table had a PK without a not-null
underneath, to prevent a slow scan of the data during restore of the
PK creation, which was particularly problematic for pg_upgrade.
- We no longer have to cope with attnotnull being set spuriously in
case a primary key is dropped indirectly (e.g., via DROP COLUMN).
Some bits of code in this patch were authored by Jian He.
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Author: Bernd Helmle <mailings@oopsware.de>
Reviewed-by: 何建 (jian he) <jian.universality@gmail.com>
Reviewed-by: 王刚 (Tender Wang) <tndrwang@gmail.com>
Reviewed-by: Justin Pryzby <pryzby@telsasoft.com>
Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Reviewed-by: Dean Rasheed <dean.a.rasheed@gmail.com>
Discussion: https://postgr.es/m/202408310358.sdhumtyuy2ht@alvherre.pgsql
The previous wording is easy to read incorrectly; this change makes it
simpler, less ambiguous, and less prominent.
Backpatch to all live branches.
Reviewed-by: Amit Langote <amitlangote09@gmail.com>
Discussion: https://postgr.es/m/202411051201.zody6mld7vkw@alvherre.pgsql
This patch builds on the work done in commit 745217a051 by enabling the
replication of generated columns alongside regular column changes through
a new publication parameter: publish_generated_columns.
Example usage:
CREATE PUBLICATION pub1 FOR TABLE tab_gencol WITH (publish_generated_columns = true);
The column list takes precedence. If the generated columns are specified
in the column list, they will be replicated even if
'publish_generated_columns' is set to false. Conversely, if generated
columns are not included in the column list (assuming the user specifies a
column list), they will not be replicated even if
'publish_generated_columns' is true.
Author: Vignesh C, Shubham Khanna
Reviewed-by: Peter Smith, Amit Kapila, Hayato Kuroda, Shlok Kyal, Ajin Cherian, Hou Zhijie, Masahiko Sawada
Discussion: https://postgr.es/m/B80D17B2-2C8E-4C7D-87F2-E5B4BE3C069E@gmail.com
This is difficult to maintain accurately, and it was probably already
somewhat incorrect, especially in the sql_drop and table_rewrite
categories.
The prior section already documented which DDL commands are *not*
supported (which was also slightly outdated), so let's expand that a
bit and just rely on that instead of listing out each command in full
detail.
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Jian He <jian.universality@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/CACJufxE_UAuxcM08BW5oVsg34v0cFWoEt8yBa5xSAoKLmL6LTQ%40mail.gmail.com
Sloppy refactoring in commit cca97ce6a caused these programs
to pass dbname = NULL to libpq if there was no "--dbname" switch
on the command line, where before "replication" would be passed.
This didn't break things completely, because the source server doesn't
care about the dbname specified for a physical replication connection.
However, it did cause libpq to fail to match a ~/.pgpass entry that
has "replication" in the dbname field. Restore the previous behavior
of passing "replication".
Also, closer inspection shows that if you do specify a dbname
in the connection string, that is what will be matched to ~/.pgpass,
not "replication". This was the pre-existing behavior so we should
not change it, but the SGML docs were pretty misleading about it.
Improve that.
Per bug #18685 from Toshi Harada. Back-patch to v17 where the
error crept in.
Discussion: https://postgr.es/m/18685-fee2dd142b9688f1@postgresql.org
Discussion: https://postgr.es/m/2702546.1730740456@sss.pgh.pa.us
"meson test" used to ignore the PG_TEST_EXTRA environment variable,
which meant that in order to run additional tests, you had to run
"meson setup -DPG_TEST_EXTRA=...". That's somewhat expensive, and not
consistent with autoconf builds. Allow PG_TEST_EXTRA environment
variable to override the setup-time option at run time, so that you
can do "PG_TEST_EXTRA=... meson test".
To implement this, the configuration time value is passed as an extra
"--pg-test-extra" argument to testwrap instead of adding it to the
test environment. If the environment variable is set at the time of
running test, testwrap uses the value from the environment variable
and ignores the --pg-test-extra option.
Now that "meson test" obeys the environment variable, we can remove it
from the "meson setup" steps in the CI script. It will now be picked
up from the environment variable like with "make check".
Author: Nazir Bilal Yavuzk, Ashutosh Bapat
Reviewed-by: Ashutosh Bapat with inputs from Tom Lane and Andrew Dunstan
Add README.non-ASCII to explain non-ASCII doc behavior; some text moved
from release.sgml.
Change UTF8 SGML characters to use HTML entities.
Remove unnecessary UTF8 spaces.
Add SVG file check for check-nbsp target.
Add dummy 'pdf' Makefile target.
Reported-by: Yugo Nagata
Discussion: https://postgr.es/m/20241011114122.c90f8a871462da36f2e2afeb@sraoss.co.jp
Backpatch-through: master
This function takes in input an array, and reverses the position of all
its elements. This operation only affects the first dimension of the
array, like array_shuffle().
The implementation structure is inspired by array_shuffle(), with a
subroutine called array_reverse_n() that may come in handy in the
future, should more functions able to reverse portions of arrays be
introduced.
Bump catalog version.
Author: Aleksander Alekseev
Reviewed-by: Ashutosh Bapat, Tom Lane, Vladlen Popolitov
Discussion: https://postgr.es/m/CAJ7c6TMpeO_ke+QGOaAx9xdJuxa7r=49-anMh3G5476e3CX1CA@mail.gmail.com
Michael Paquier