The PostgreSQL limitations section of the documents mentioned the limit
on the number of columns that can exist in a table. Users might be
surprised to find that there's also a limit on the number of columns that
can exist in a targetlist. Users may experience restrictions which
surprise them if they happened to select a large number of columns from
several tables with many columns. Here we document that there is a
limitation on this and mention what that limit actually is.
Wording proposal by Alvaro Herrera
Reported-by: Vladimir Sitnikov
Author: Dave Crammer
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/CAB=Je-E18aTYpNqje4mT0iEADpeGLSzwUvo3H9kRRuDdsNo4aQ@mail.gmail.com
Backpatch-through: 12, where the limitations section was added
We hadn't noticed this because (a) few people feed invalid
timezone abbreviation files to the server, and (b) in typical
scenarios guc.c would throw ereport(ERROR) and then transaction
abort handling would silently clean up the leaked file reference.
However, it was possible to observe file leakage warnings if one
breaks an already-active abbreviation file, because guc.c does
not throw ERROR when loading supposedly-validated settings during
session start or SIGHUP processing.
Report and fix by Kyotaro Horiguchi (cosmetic adjustments by me)
Discussion: https://postgr.es/m/20220530.173740.748502979257582392.horikyota.ntt@gmail.com
runtime.sgml contains a passing reference to the minimum server
version that pg_dump[all] can dump from. That was 7.0 for many
years, but when 64f3524e2 raised it to 8.0, we missed updating this
bit. Then when 30e7c175b raised it to 9.2, we missed it again.
Given that track record, I'm not too hopeful that we'll remember
to fix this in future changes ... but for now, make the docs match
reality in each branch.
Noted by Daniel Westermann.
Discussion: https://postgr.es/m/GV0P278MB041917EB3E2FE8704B5AE2C6D2DC9@GV0P278MB0419.CHEP278.PROD.OUTLOOK.COM
The information generated when track_activities is accessible to
superusers, roles with the privileges of pg_read_all_stats, as well as
roles one has the privileges of. The original text did not outline the
last point, while the change done in ac1ae47 was unclear about the
second point.
Per discussion with Nathan Bossart.
Discussion: https://postgr.es/m/20220521185743.GA886636@nathanxps13
Backpatch-through: 10
If a short description is specified as NULL in one of the various
DefineCustomXXXVariable() functions available to external modules to
define a custom parameter, SHOW ALL would crash. This change teaches
SHOW ALL to properly handle NULL short descriptions, as well as any code
paths that manipulate it, to gain in flexibility. Note that
help_config.c was already able to do that, when describing a set of GUCs
for postgres --describe-config.
Author: Steve Chavez
Reviewed by: Nathan Bossart, Andres Freund, Michael Paquier, Tom Lane
Discussion: https://postgr.es/m/CAGRrpzY6hO-Kmykna_XvsTv8P2DshGiU6G3j8yGao4mk0CqjHA%40mail.gmail.com
Backpatch-through: 10
Commits a59c79564 et al. tried to sync libpq's SSL key file
permissions checks with what we've used for years in the backend.
We did not intend to create any new failure cases, but it turns out
we did: restricting the key file's ownership breaks cases where the
client is allowed to read a key file despite not having the identical
UID. In particular a client running as root used to be able to read
someone else's key file; and having seen that I suspect that there are
other, less-dubious use cases that this restriction breaks on some
platforms.
We don't really need an ownership check, since if we can read the key
file despite its having restricted permissions, it must have the right
ownership --- under normal conditions anyway, and the point of this
patch is that any additional corner cases where that works should be
deemed allowable, as they have been historically. Hence, just drop
the ownership check, and rearrange the permissions check to get rid
of its faulty assumption that geteuid() can't be zero. (Note that the
comparable backend-side code doesn't have to cater for geteuid() == 0,
since the server rejects that very early on.)
This does have the end result that the permissions safety check used
for a root user's private key file is weaker than that used for
anyone else's. While odd, root really ought to know what she's doing
with file permissions, so I think this is acceptable.
Per report from Yogendra Suralkar. Like the previous patch,
back-patch to all supported branches.
Discussion: https://postgr.es/m/MW3PR15MB3931DF96896DC36D21AFD47CA3D39@MW3PR15MB3931.namprd15.prod.outlook.com
Foreign tables can be partitioned, but previous documentation commits
left the syntax synopsis both incomplete and incorrect.
Justin Pryzby and Amit Langote
Discussion: http://postgr.es/m/20220521130922.GX19626@telsasoft.com
ruleutils.c was coded to suppress the AS label for a SELECT output
expression if the column name is "?column?", which is the parser's
fallback if it can't think of something better. This is fine, and
avoids ugly clutter, so long as (1) nothing further up in the parse
tree relies on that column name or (2) the same fallback would be
assigned when the rule or view definition is reloaded. Unfortunately
(2) is far from certain, both because ruleutils.c might print the
expression in a different form from how it was originally written
and because FigureColname's rules might change in future releases.
So we shouldn't rely on that.
Detecting exactly whether there is any outer-level use of a SELECT
column name would be rather expensive. This patch takes the simpler
approach of just passing down a flag indicating whether there *could*
be any outer use; for example, the output column names of a SubLink
are not referenceable, and we also do not care about the names exposed
by the right-hand side of a setop. This is sufficient to suppress
unwanted clutter in all but one case in the regression tests. That
seems like reasonable evidence that it won't be too much in users'
faces, while still fixing the cases we need to fix.
Per bug #17486 from Nicolas Lutic. This issue is ancient, so
back-patch to all supported branches.
Discussion: https://postgr.es/m/17486-1ad6fd786728b8af@postgresql.org
The description of track_activities mentioned that it is visible to
superusers and that the information related to the current session can
be seen, without telling about pg_read_all_stats. Roles that are
granted the privileges of pg_read_all_stats can also see this
information, so mention it in the docs.
Author: Ian Barwick
Reviewed-by: Nathan Bossart
Discussion: https://postgr.es/m/CAB8KJ=jhPyYFu-A5r-ZGP+Ax715mUKsMxAGcEQ9Cx_mBAmrPow@mail.gmail.com
Backpatch-through: 10
When an implicit operator family is created, it wasn't getting reported.
Make it do so.
This has always been missing. Backpatch to 10.
Author: Masahiko Sawada <sawada.mshk@gmail.com>
Reported-by: Leslie LEMAIRE <leslie.lemaire@developpement-durable.gouv.fr>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Michael Paquiër <michael@paquier.xyz>
Discussion: https://postgr.es/m/f74d69e151b22171e8829551b1159e77@developpement-durable.gouv.fr
A new plpgsql test function was added in 14 and up to cover for a bugfix
that was not backpatchable. We can add it to older versions as a way to
cover other bits of DDL event triggers, with an exception clause to
avoid the problematic corner case.
Originally authored by Michaël Paquier.
Backpatch: 10 through 13.
Discussion: https://postgr.es/m/202205201523.7m5jbfvyanmj@alvherre.pgsql
The documentation didn't specify the name of the per-user service file
on Windows, and extrapolating from the pattern used for other config
files gave the wrong answer. The fact that it isn't consistent with the
others sure seems like a bug, but it's far too late to change that now;
we'd just penalize people who worked it out in the past. So, simply
document the true state of affairs.
In passing, fix some gratuitous differences between the discussions
of the service file and the password file.
Julien Rouhaud, per question from Dominique Devienne.
Backpatch to all supported branches. I (tgl) also chose to back-patch
the part of commit ba356a397 that touched libpq.sgml's description of
the service file --- in hindsight, I'm not sure why I didn't do so at
the time, as it includes some fairly essential information.
Discussion: https://postgr.es/m/CAFCRh-_mdLrh8eYVzhRzu4c8bAFEBn=rwoHOmFJcQOTsCy5nig@mail.gmail.com
This is a slight, convenient semantics change from what commit
0f0cfb4940 ("Fix parallel operations that prevent oldest xmin from
advancing") introduced that lets us simplify the coding in the one place
where it is used.
Backpatch to 13. This is related to commit 6fea65508a ("Tighten
ComputeXidHorizons' handling of walsenders") rewriting the code site
where this is used, which has not yet been backpatched, but it may well
be in the future.
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Discussion: https://postgr.es/m/202204191637.eldwa2exvguw@alvherre.pgsql
We weren't checking the length of the column list in the alias clause of
an XMLTABLE or JSON_TABLE function (a "tablefunc" RTE), and it was
possible to make the server crash by passing an overly long one. Fix it
by throwing an error in that case, like the other places that deal with
alias lists.
In passing, modify the equivalent test used for join RTEs to look like
the other ones, which was different for no apparent reason.
This bug came in when XMLTABLE was born in version 10; backpatch to all
stable versions.
Reported-by: Wang Ke <krking@zju.edu.cn>
Discussion: https://postgr.es/m/17480-1c9d73565bb28e90@postgresql.org
If a cluster is promoted (aka the control file shows a state different
than DB_IN_ARCHIVE_RECOVERY) while CreateRestartPoint() is still
processing, this function could miss an update of the control file for
"checkPoint" and "checkPointCopy" but still do the recycling and/or
removal of the past WAL segments, assuming that the to-be-updated LSN
values should be used as reference points for the cleanup. This causes
a follow-up restart attempting crash recovery to fail with a PANIC on a
missing checkpoint record if the end-of-recovery checkpoint triggered by
the promotion did not complete while the cluster abruptly stopped or
crashed before the completion of this checkpoint. The PANIC would be
caused by the redo LSN referred in the control file as located in a
segment already gone, recycled by the previous restartpoint with
"checkPoint" out-of-sync in the control file.
This commit fixes the update of the control file during restartpoints so
as "checkPoint" and "checkPointCopy" are updated even if the cluster has
been promoted while a restartpoint is running, to be on par with the set
of WAL segments actually recycled in the end of CreateRestartPoint().
7863ee4 has fixed this problem already on master, but the release timing
of the latest point versions did not let me enough time to study and fix
that on all the stable branches.
Reported-by: Fujii Masao, Rui Zhao
Author: Kyotaro Horiguchi
Reviewed-by: Nathan Bossart, Michael Paquier
Discussion: https://postgr.es/m/20220316.102444.2193181487576617583.horikyota.ntt@gmail.com
Backpatch-through: 10
This follows in the footsteps of commit 2591ee8ec by removing one more
ill-advised shortcut from planning of GroupingFuncs. It's true that
we don't intend to execute the argument expression(s) at runtime, but
we still have to process any Vars appearing within them, or we risk
failure at setrefs.c time (or more fundamentally, in EXPLAIN trying
to print such an expression). Vars in upper plan nodes have to have
referents in the next plan level, whether we ever execute 'em or not.
Per bug #17479 from Michael J. Sullivan. Back-patch to all supported
branches.
Richard Guo
Discussion: https://postgr.es/m/17479-6260deceaf0ad304@postgresql.org
The problem is that we don't send keep-alive messages for a long time
while processing large transactions during logical replication where we
don't send any data of such transactions. This can happen when the table
modified in the transaction is not published or because all the changes
got filtered. We do try to send the keep_alive if necessary at the end of
the transaction (via WalSndWriteData()) but by that time the
subscriber-side can timeout and exit.
To fix this we try to send the keepalive message if required after
processing certain threshold of changes.
Reported-by: Fabrice Chapuis
Author: Wang wei and Amit Kapila
Reviewed By: Masahiko Sawada, Euler Taveira, Hou Zhijie, Hayato Kuroda
Backpatch-through: 10
Discussion: https://postgr.es/m/CAA5-nLARN7-3SLU_QUxfy510pmrYK6JJb=bk3hcgemAM_pAv+w@mail.gmail.com
The current setup assumes that commands for lz4, zstd and gzip always
exist by default if not enforced by a user's environment. However,
vcpkg, as one example, installs libraries but no binaries, so this
default setup to assume that a command should always be present would
cause failures. This commit improves the detection of such external
commands as follows:
* If a ENV value is available, trust the environment/user and use it.
* If a ENV value is not available, check its execution by looking in the
current PATH, by launching a simple "$command --version" (that should be
portable enough).
** On execution failure, ignore ENV{command}.
** On execution success, set ENV{command} = "$command".
Note that this new rule applies to gzip, lz4 and zstd but not tar that
we assume will always exist. Those commands are set up in the
environment only when using bincheck and taptest. The CI includes all
those commands and I have checked that their setup is correct there. I
have also tested this change in a MSVC environment where we have none of
those commands.
While on it, remove the references to lz4 from the documentation and
vcregress.pl in ~v13. --with-lz4 has been added in v14~ so there is no
point to have this information in these older branches.
Reported-by: Andrew Dunstan
Reviewed-by: Andrew Dunstan
Discussion: https://postgr.es/m/14402151-376b-a57a-6d0c-10ad12608e12@dunslane.net
Backpatch-through: 10
In OpenLDAP 2.5 and later, libldap itself is always thread-safe and
there's never a libldap_r. Our existing coding dealt with that
by assuming it wouldn't find libldap_r if libldap is thread-safe.
But that rule fails to cope if there are multiple OpenLDAP versions
visible, as is likely to be the case on macOS in particular. We'd
end up using shiny new libldap in the backend and a hoary libldap_r
in libpq.
Instead, once we've found libldap, check if it's >= 2.5 (by
probing for a function introduced then) and don't bother looking
for libldap_r if so. While one can imagine library setups that
this'd still give the wrong answer for, they seem unlikely to
occur in practice.
Per report from Peter Eisentraut. Back-patch to all supported branches.
Discussion: https://postgr.es/m/fedacd7c-2a38-25c9-e7ff-dea549d0e979@enterprisedb.com
The parser code that transformed VALUES from row-oriented to
column-oriented lists failed if there were zero columns.
You can't write that straightforwardly (though probably you
should be able to), but the case can be reached by expanding
a "tab.*" reference to a zero-column table.
Per bug #17477 from Wang Ke. Back-patch to all supported branches.
Discussion: https://postgr.es/m/17477-0af3c6ac6b0a6ae0@postgresql.org
This reverts commit eafdf9de06
and its back-branch counterparts. Corey Huinker pointed out that
we'd discussed this exact change back in 2016 and rejected it,
on the grounds that there's at least one usage pattern with LIMIT
where an infinite endpoint can usefully be used. Perhaps that
argument needs to be re-litigated, but there's no time left before
our back-branch releases. To keep our options open, restore the
status quo ante; if we do end up deciding to change things, waiting
one more quarter won't hurt anything.
Rather than just doing a straight revert, I added a new test case
demonstrating the usage with LIMIT. That'll at least remind us of
the issue if we forget again.
Discussion: https://postgr.es/m/3603504.1652068977@sss.pgh.pa.us
Discussion: https://postgr.es/m/CADkLM=dzw0Pvdqp5yWKxMd+VmNkAMhG=4ku7GnCZxebWnzmz3Q@mail.gmail.com
It intended to, but did not, achieve this. Adopt the new standard of
setting user ID just after locking the relation. Back-patch to v10 (all
supported versions).
Reviewed by Simon Riggs. Reported by Alvaro Herrera.
Security: CVE-2022-1552
When a feature enumerates relations and runs functions associated with
all found relations, the feature's user shall not need to trust every
user having permission to create objects. BRIN-specific functionality
in autovacuum neglected to account for this, as did pg_amcheck and
CLUSTER. An attacker having permission to create non-temp objects in at
least one schema could execute arbitrary SQL functions under the
identity of the bootstrap superuser. CREATE INDEX (not a
relation-enumerating operation) and REINDEX protected themselves too
late. This change extends to the non-enumerating amcheck interface.
Back-patch to v10 (all supported versions).
Sergey Shinderuk, reviewed (in earlier versions) by Alexander Lakhin.
Reported by Alexander Lakhin.
Security: CVE-2022-1552
f40d362a66 disabled part of 031_recovery_conflict.pl due to instability
that's not trivial to fix in the back branches. That fixed most of the
issues. But there was one more failure (on lapwing / REL_10_STABLE).
That failure looks like it might be caused by a genuine problem. Disable the
test until after the set of releases, to avoid packagers etc potentially
having to fight with a test failure they can't do anything about.
Discussion: https://postgr.es/m/3447060.1652032749@sss.pgh.pa.us
Backpatch: 10-14
The recovery deadlock test has a timing issue that was fixed in 5136967f1e in
HEAD. Unfortunately the same fix doesn't quite work in the back branches: 1)
adjust_conf() doesn't exist, which is easy enough to work around 2) a restart
cleares the recovery conflict stats < 15.
These issues can be worked around, but given the upcoming set of minor
releases, skip the problematic test for now. The buildfarm doesn't show
failures in other parts of 031_recovery_conflict.pl.
Discussion: https://postgr.es/m/20220506155827.dfnaheq6ufylwrqf@alap3.anarazel.de
Backpatch: 10-14
The tests added in 9f8a050f68 failed nearly reliably on FreeBSD in CI, and
occasionally on the buildfarm. That turns out to be caused not by a bug in the
test, but by a longstanding bug in recovery conflict handling.
The standby timeout handler, used by ResolveRecoveryConflictWithBufferPin(),
executed SendRecoveryConflictWithBufferPin() inside a signal handler. A bad
idea, because the deadlock timeout handler (or a spurious latch set) could
have interrupted ProcWaitForSignal(). If unlucky that could cause a
self-deadlock on ProcArrayLock, if the deadlock check is in
SendRecoveryConflictWithBufferPin()->CancelDBBackends().
To fix, set a flag in StandbyTimeoutHandler(), and check the flag in
ResolveRecoveryConflictWithBufferPin().
Subsequently the recovery conflict tests will be backpatched.
Discussion: https://postgr.es/m/20220413002626.udl7lll7f3o7nre7@alap3.anarazel.de
Backpatch: 10-
For some reason by default the mingw C Runtime takes it upon itself to
expand program arguments that look like shell globbing characters. That
has caused much scratching of heads and mis-attribution of the causes of
some TAP test failures, so stop doing that.
This removes an inconsistency with Windows binaries built with MSVC,
which have no such behaviour.
Per suggestion from Noah Misch.
Backpatch to all live branches.
Discussion: https://postgr.es/m/20220423025927.GA1274057@rfd.leadboat.com
inline_cte() expected to find exactly as many references to the
target CTE as its cterefcount indicates. While that should be
accurate for the tree as emitted by the parser, there are some
optimizations that occur upstream of here that could falsify it,
notably removal of unused subquery output expressions.
Trying to make the accounting 100% accurate seems expensive and
doomed to future breakage. It's not really worth it, because
all this code is protecting is downstream assumptions that every
referenced CTE has a plan. Let's convert those assertions to
regular test-and-elog just in case there's some actual problem,
and then drop the failing assertion.
Per report from Tomas Vondra (thanks also to Richard Guo for
analysis). Back-patch to v12 where the faulty code came in.
Discussion: https://postgr.es/m/29196a1e-ed47-c7ca-9be2-b1c636816183@enterprisedb.com
Commit b3b4d8e68a moved our perl test modules to a better namespace
structure, but this has made life hard for people wishing to backpatch
improvements in the TAP tests. Here we alleviate much of that difficulty
by implementing the new module names on top of the old modules, mostly
by using a little perl typeglob aliasing magic, so that we don't have a
dual maintenance burden. This should work both for the case where a new
test is backpatched and the case where a fix to an existing test that
uses the new namespace is backpatched.
Reviewed by Michael Paquier
Per complaint from Andres Freund
Discussion: https://postgr.es/m/20220418141530.nfxtkohefvwnzncl@alap3.anarazel.de
Applied to branches 10 through 14
CLUSTER sort won't use the datum1 SortTuple field when clustering
against an index whose leading key is an expression. This makes it
unsafe to use the abbreviated keys optimization, which was missed by the
logic that sets up SortSupport state. Affected tuplesorts output tuples
in a completely bogus order as a result (the wrong SortSupport based
comparator was used for the leading attribute).
This issue is similar to the bug fixed on the master branch by recent
commit cc58eecc5d. But it's a far older issue, that dates back to the
introduction of the abbreviated keys optimization by commit 4ea51cdfe8.
Backpatch to all supported versions.
Author: Peter Geoghegan <pg@bowt.ie>
Author: Thomas Munro <thomas.munro@gmail.com>
Discussion: https://postgr.es/m/CA+hUKG+bA+bmwD36_oDxAoLrCwZjVtST2fqe=b4=qZcmU7u89A@mail.gmail.com
Backpatch: 10-
Such cases will lead to infinite loops, so they're of no practical
value. The numeric variant of generate_series() already threw error
for this, so borrow its message wording.
Per report from Richard Wesley. Back-patch to all supported branches.
Discussion: https://postgr.es/m/91B44E7B-68D5-448F-95C8-B4B3B0F5DEAF@duckdblabs.com
An ALTER FUNCTION command that tried to update both the function's
proparallel property and its proconfig list failed to do the former,
because it stored the new proparallel value into a tuple that was
no longer the interesting one. Carelessness in 7aea8e4f2.
(I did not bother with a regression test, because the only likely
future breakage would be for someone to ignore the comment I added
and add some other field update after the heap_modify_tuple step.
A test using existing function properties could not catch that.)
Per report from Bryn Llewellyn. Back-patch to all supported branches.
Discussion: https://postgr.es/m/8AC9A37F-99BD-446F-A2F7-B89AD0022774@yugabyte.com
Don't try to look at the attidentity field of system attributes,
because they're not there in the TupleDescAttr array. Sometimes
this is harmless because we accidentally pick up a zero, but
otherwise we'll report "no owned sequence found" from an attempt
to alter a system attribute. (It seems possible that a SIGSEGV
could occur, too, though I've not seen it in testing.)
It's not in this function's charter to complain that you can't
alter a system column, so instead just hard-wire an assumption
that system attributes aren't identities. I didn't bother with
a regression test because the appearance of the bug is very
erratic.
Per bug #17465 from Roman Zharkov. Back-patch to all supported
branches. (There's not actually a live bug before v12, because
before that get_attidentity() did the right thing anyway.
But for consistency I changed the test in the older branches too.)
Discussion: https://postgr.es/m/17465-f2a554a6cb5740d3@postgresql.org
This test, introduced in df86e52, uses a second standby to check that
it is able to remove correctly RECOVERYHISTORY and RECOVERYXLOG at the
end of recovery. This standby uses the archives of the primary to
restore its contents, with some of the archive's contents coming from
the first standby previously promoted. In slow environments, it was
possible that the test did not check what it should, as the history file
generated by the promotion of the first standby may not be stored yet on
the archives the second standby feeds on. So, it could be possible that
the second standby selects an incorrect timeline, without restoring a
history file at all.
This commits adds a wait phase to make sure that the history file
required by the second standby is archived before this cluster is
created. This relies on poll_query_until() with pg_stat_file() and an
absolute path, something not supported in REL_10_STABLE.
While on it, this adds a new test to check that the history file has
been restored by looking at the logs of the second standby. This
ensures that a RECOVERYHISTORY, whose removal needs to be checked,
is created in the first place. This should make the test more robust.
This test has been introduced by df86e52, but it came in light as an
effect of the bug fixed by acf1dd42, where the extra restore_command
calls made the test much slower.
Reported-by: Andres Freund
Discussion: https://postgr.es/m/YlT23IvsXkGuLzFi@paquier.xyz
Backpatch-through: 11
The target failed, tested $PATH binaries, or tested a stale temporary
installation. Commit c66b438db6 missed
this. Back-patch to v10 (all supported versions).
David Rowley
Tom Lane
Michael Paquier
Robert Haas
Alvaro Herrera
Amit Kapila
Noah Misch
Peter Eisentraut
Andres Freund
Etsuro Fujita
Andrew Dunstan
Peter Geoghegan