Michael Paquier [Fri, 15 Nov 2024 02:32:18 +0000 (11:32 +0900)]
Fix race conditions with drop of reused pgstats entries
This fixes a set of race conditions with cumulative statistics where a
shared stats entry could be dropped while it should still be valid in
the event when it is reused: an entry may refer to a different object
but requires the same hash key. This can happen with various stats
kinds, like:
- Replication slots that compute internally an index number, for
different slot names.
- Stats kinds that use an OID in the object key, where a wraparound
causes the same key to be used if an OID is used for the same object.
- As of PostgreSQL 18, custom pgstats kinds could also be an issue,
depending on their implementation.
This issue is fixed by introducing a counter called "generation" in the
shared entries via PgStatShared_HashEntry, initialized at 0 when an
entry is created and incremented when the same entry is reused, to avoid
concurrent issues on drop because of other backends still holding a
reference to it. This "generation" is copied to the local copy that a
backend holds when looking at an object, then cross-checked with the
shared entry to make sure that the entry is not dropped even if its
"refcount" justifies that if it has been reused.
This problem could show up when a backend shuts down and needs to
discard any entries it still holds, causing statistics to be removed
when they should not, or even an assertion failure. Another report
involved a failure in a standby after an OID wraparound, where the
startup process would FATAL on a "can only drop stats once", stopping
recovery abruptly. The buildfarm has been sporadically complaining
about the problem, as well, but the window is hard to reach with the
in-core tests.
Note that the issue can be reproduced easily by adding a sleep before
dshash_find() in pgstat_release_entry_ref() to enlarge the problematic
window while repeating test_decoding's isolation test oldest_xmin a
couple of times, for example, as pointed out by Alexander Lakhin.
Reported-by: Alexander Lakhin, Peter Smith
Author: Kyotaro Horiguchi, Michael Paquier Reviewed-by: Bertrand Drouvot
Discussion: https://postgr.es/m/CAA4eK1KxuMVyAryz_Vk5yq3ejgKYcL6F45Hj9ZnMNBS-g+PuZg@mail.gmail.com
Discussion: https://postgr.es/m/17947-b9554521ad963c9c@postgresql.org
Backpatch-through: 15
The current code calls array_eq() and does not provide FmgrInfo. This commit
provides initialization of FmgrInfo and uses C collation as the safe option
for text comparison because we don't know anything about the semantics of
opclass options.
Backpatch to 13, where opclass options were introduced.
Reported-by: Nicolas Maus
Discussion: https://postgr.es/m/18692-72ea398df3ec6712%40postgresql.org
Backpatch-through: 13
Tom Lane [Mon, 11 Nov 2024 22:05:53 +0000 (17:05 -0500)]
Parallel workers use AuthenticatedUserId for connection privilege checks.
Commit 5a2fed911 had an unexpected side-effect: the parallel worker
launched for the new test case would fail if it couldn't use a
superuser-reserved connection slot. The reason that test failed
while all our pre-existing ones worked is that the connection
privilege tests in InitPostgres had been based on the superuserness
of the leader's AuthenticatedUserId, but after the rearrangements
of 5a2fed911 we were testing the superuserness of CurrentUserId,
which the new test case deliberately made to be a non-superuser.
This all seems very accidental and probably not the behavior we really
want, but a security patch is no time to be redesigning things.
Pending some discussion about desirable semantics, hack it so that
InitPostgres continues to pay attention to the superuserness of
AuthenticatedUserId when starting a parallel worker.
Nathan Bossart and Tom Lane, per buildfarm member sawshark.
Tom Lane [Mon, 11 Nov 2024 18:57:21 +0000 (13:57 -0500)]
Fix cross-version upgrade tests.
TestUpgradeXversion knows how to make the main regression database's
references to pg_regress.so be version-independent. But it doesn't
do that for plperl's database, so that the C function added by
commit b7e3a52a8 is causing cross-version upgrade test failures.
Path of least resistance is to just drop the function at the end
of the new test.
In <= v14, also take the opportunity to clean up the generated
test files.
Noah Misch [Mon, 11 Nov 2024 18:55:18 +0000 (10:55 -0800)]
src/tools/msvc: Respect REGRESS_OPTS in plcheck.
v16 commit 8fe3e697a1a83a722b107c7cb9c31084e1f4d077 used REGRESS_OPTS in
a way needing this. That broke "vcregress plcheck". Back-patch
v16..v12; newer versions don't have this build system.
Tom Lane [Mon, 11 Nov 2024 15:29:54 +0000 (10:29 -0500)]
Fix improper interactions between session_authorization and role.
The SQL spec mandates that SET SESSION AUTHORIZATION implies
SET ROLE NONE. We tried to implement that within the lowest-level
functions that manipulate these settings, but that was a bad idea.
In particular, guc.c assumes that it doesn't matter in what order
it applies GUC variable updates, but that was not the case for these
two variables. This problem, compounded by some hackish attempts to
work around it, led to some security-grade issues:
* Rolling back a transaction that had done SET SESSION AUTHORIZATION
would revert to SET ROLE NONE, even if that had not been the previous
state, so that the effective user ID might now be different from what
it had been.
* The same for SET SESSION AUTHORIZATION in a function SET clause.
* If a parallel worker inspected current_setting('role'), it saw
"none" even when it should see something else.
Also, although the parallel worker startup code intended to cope
with the current role's pg_authid row having disappeared, its
implementation of that was incomplete so it would still fail.
Fix by fully separating the miscinit.c functions that assign
session_authorization from those that assign role. To implement the
spec's requirement, teach set_config_option itself to perform "SET
ROLE NONE" when it sets session_authorization. (This is undoubtedly
ugly, but the alternatives seem worse. In particular, there's no way
to do it within assign_session_authorization without incompatible
changes in the API for GUC assign hooks.) Also, improve
ParallelWorkerMain to directly set all the relevant user-ID variables
instead of relying on some of them to get set indirectly. That
allows us to survive not finding the pg_authid row during worker
startup.
In v16 and earlier, this includes back-patching 9987a7bf3 which
fixed a violation of GUC coding rules: SetSessionAuthorization
is not an appropriate place to be throwing errors from.
Nathan Bossart [Mon, 11 Nov 2024 15:00:00 +0000 (09:00 -0600)]
Ensure cached plans are correctly marked as dependent on role.
If a CTE, subquery, sublink, security invoker view, or coercion
projection references a table with row-level security policies, we
neglected to mark the plan as potentially dependent on which role
is executing it. This could lead to later executions in the same
session returning or hiding rows that should have been hidden or
returned instead.
Reported-by: Wolfgang Walther Reviewed-by: Noah Misch
Security: CVE-2024-10976
Backpatch-through: 12
Noah Misch [Mon, 11 Nov 2024 14:23:43 +0000 (06:23 -0800)]
Block environment variable mutations from trusted PL/Perl.
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.
Michael Paquier [Mon, 11 Nov 2024 01:19:59 +0000 (10:19 +0900)]
libpq: Bail out during SSL/GSS negotiation errors
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
Tom Lane [Fri, 8 Nov 2024 18:42:01 +0000 (13:42 -0500)]
Improve fix for not entering parallel mode when holding interrupts.
Commit ac04aa84a put the shutoff for this into the planner, which is
not ideal because it doesn't prevent us from re-using a previously
made parallel plan. Revert the planner change and instead put the
shutoff into InitializeParallelDSM, modeling it on the existing code
there for recovering from failure to allocate a DSM segment.
However, that code path is mostly untested, and testing a bit harder
showed there's at least one bug: ExecHashJoinReInitializeDSM is not
prepared for us to have skipped doing parallel DSM setup. I also
thought the Assert in ReinitializeParallelWorkers is pretty
ill-advised, and replaced it with a silent Min() operation.
The existing test case added by ac04aa84a serves fine to test this
version of the fix, so no change needed there.
Patch by me, but thanks to Noah Misch for the core idea that we
could shut off worker creation when !INTERRUPTS_CAN_BE_PROCESSED.
Back-patch to v12, as ac04aa84a was.
Amit Langote [Fri, 8 Nov 2024 07:30:22 +0000 (16:30 +0900)]
Disallow partitionwise join when collations don't match
If the collation of any join key column doesn’t match the collation of
the corresponding partition key, partitionwise joins can yield incorrect
results. For example, rows that would match under the join key collation
might be located in different partitions due to the partitioning
collation. In such cases, a partitionwise join would yield different
results from a non-partitionwise join, so disallow it in such cases.
Reported-by: Tender Wang <tndrwang@gmail.com>
Author: Jian He <jian.universality@gmail.com> Reviewed-by: Tender Wang <tndrwang@gmail.com> Reviewed-by: Junwang Zhao <zhjwpku@gmail.com>
Discussion: https://postgr.es/m/CAHewXNno_HKiQ6PqyLYfuqDtwp7KKHZiH1J7Pqyz0nr+PS2Dwg@mail.gmail.com
Backpatch-through: 12
Amit Langote [Fri, 8 Nov 2024 07:06:58 +0000 (16:06 +0900)]
Disallow partitionwise grouping when collations don't match
If the collation of any grouping column doesn’t match the collation of
the corresponding partition key, partitionwise grouping can yield
incorrect results. For example, rows that would be grouped under the
grouping collation may end up in different partitions under the
partitioning collation. In such cases, full partitionwise grouping
would produce results that differ from those without partitionwise
grouping, so disallowed that.
Partial partitionwise aggregation is still allowed, as the Finalize
step reconciles partition-level aggregates with grouping requirements
across all partitions, ensuring that the final output remains
consistent.
This commit also fixes group_by_has_partkey() by ensuring the
RelabelType node is stripped from grouping expressions when matching
them to partition key expressions to avoid false mismatches.
Bug: #18568 Reported-by: Webbo Han <1105066510@qq.com>
Author: Webbo Han <1105066510@qq.com> Reviewed-by: Tender Wang <tndrwang@gmail.com> Reviewed-by: Aleksander Alekseev <aleksander@timescale.com> Reviewed-by: Jian He <jian.universality@gmail.com>
Discussion: https://postgr.es/m/18568-2a9afb6b9f7e6ed3@postgresql.org
Discussion: https://postgr.es/m/tencent_9D9103CDA420C07768349CC1DFF88465F90A@qq.com
Discussion: https://postgr.es/m/CAHewXNno_HKiQ6PqyLYfuqDtwp7KKHZiH1J7Pqyz0nr+PS2Dwg@mail.gmail.com
Backpatch-through: 12
Thomas Munro [Sat, 6 Aug 2022 00:02:43 +0000 (12:02 +1200)]
Replace pgwin32_is_junction() with lstat().
Now that lstat() reports junction points with S_IFLNK/S_ISLINK(), and
unlink() can unlink them, there is no need for conditional code for
Windows in a few places. That was expressed by testing for WIN32 or
S_ISLNK, which we can now constant-fold.
The coding around pgwin32_is_junction() was a bit suspect anyway, as we
never checked for errors, and we also know that errors can be spuriously
reported because of transient sharing violations on this OS. The
lstat()-based code has handling for that.
This also reverts 4fc6b6ee on master only. That was done because
lstat() didn't previously work for symlinks (junction points), but now
it does.
Tested-by: Andrew Dunstan <andrew@dunslane.net>
Discussion: https://postgr.es/m/CA%2BhUKGLfOOeyZpm5ByVcAt7x5Pn-%3DxGRNCvgiUPVVzjFLtnY0w%40mail.gmail.com
(cherry picked from commit 5fc88c5d53e43fa7dcea93499d230a0bf70f4f77)
Author: Thomas Munro <tmunro@postgresql.org>
Author: Alexandra Wang <alexandra.wang.oss@gmail.com>
Thomas Munro [Tue, 25 Oct 2022 02:20:00 +0000 (15:20 +1300)]
Fix lstat() for broken junction points on Windows.
When using junction points to emulate symlinks on Windows, one edge case
was not handled correctly by commit c5cb8f3b: if a junction point is
broken (pointing to a non-existent path), we'd report ENOENT. This
doesn't break any known use case, but was noticed while developing a
test suite for these functions and is fixed here for completeness.
Also add translation ERROR_CANT_RESOLVE_FILENAME -> ENOENT, as that is
one of the errors Windows can report for some kinds of broken paths.
Discussion: https://postgr.es/m/CA%2BhUKG%2BajSQ_8eu2AogTncOnZ5me2D-Cn66iN_-wZnRjLN%2Bicg%40mail.gmail.com
(cherry picked from commit 387803d81d6256fcb60b9192bb5b00042442b4e3)
Author: Thomas Munro <tmunro@postgresql.org>
Author: Alexandra Wang <alexandra.wang.oss@gmail.com>
Thomas Munro [Sat, 6 Aug 2022 00:00:57 +0000 (12:00 +1200)]
Provide lstat() for Windows.
Junction points will be reported with S_ISLNK(x.st_mode), simulating
POSIX lstat(). stat() will follow pseudo-symlinks, like in POSIX (but
only one level before giving up, unlike in POSIX).
Thomas Munro [Wed, 6 Nov 2024 09:04:44 +0000 (22:04 +1300)]
Monkey-patch LLVM code to fix ARM relocation bug.
Supply a new memory manager for RuntimeDyld, to avoid crashes in
generated code caused by memory placement that can overflow a 32 bit
data type. This is a drop-in replacement for the
llvm::SectionMemoryManager class in the LLVM library, with Michael
Smith's proposed fix from
https://www.github.com/llvm/llvm-project/pull/71968.
We hereby slurp it into our own source tree, after moving into a new
namespace llvm::backport and making some minor adjustments so that it
can be compiled with older LLVM versions as far back as 12. It's harder
to make it work on even older LLVM versions, but it doesn't seem likely
that people are really using them so that is not investigated for now.
The problem could also be addressed by switching to JITLink instead of
RuntimeDyld, and that is the LLVM project's recommended solution as
the latter is about to be deprecated. We'll have to do that soon enough
anyway, and then when the LLVM version support window advances far
enough in a few years we'll be able to delete this code. Unfortunately
that wouldn't be enough for PostgreSQL today: in most relevant versions
of LLVM, JITLink is missing or incomplete.
Several other projects have already back-ported this fix into their fork
of LLVM, which is a vote of confidence despite the lack of commit into
LLVM as of today. We don't have our own copy of LLVM so we can't do
exactly what they've done; instead we have a copy of the whole patched
class so we can pass an instance of it to RuntimeDyld.
The LLVM project hasn't chosen to commit the fix yet, and even if it
did, it wouldn't be back-ported into the releases of LLVM that most of
our users care about, so there is not much point in waiting any longer
for that. If they make further changes and commit it to LLVM 19 or 20,
we'll still need this for older versions, but we may want to
resynchronize our copy and update some comments.
The changes that we've had to make to our copy can be seen by diffing
our SectionMemoryManager.{h,cpp} files against the ones in the tree of
the pull request. Per the LLVM project's license requirements, a copy
is in SectionMemoryManager.LICENSE.
This should fix the spate of crash reports we've been receiving lately
from users on large memory ARM systems.
Michael Paquier [Tue, 5 Nov 2024 00:41:01 +0000 (09:41 +0900)]
Clear padding of PgStat_HashKey when handling pgstats entries
PgStat_HashKey is currently initialized in a way that could result in
random data if the structure has any padding bytes. The structure
has no padding bytes currently, fortunately, but it could become a
problem should the structure change at some point in the future.
The code is changed to use some memset(0) so as any padding would be
handled properly, as it would be surprising to see random failures in
the pgstats entry lookups. PgStat_HashKey is a structure internal to
pgstats, and an ABI change could be possible in the scope of a bug fix,
so backpatch down to 15 where this has been introduced.
Noah Misch [Sun, 3 Nov 2024 02:42:52 +0000 (19:42 -0700)]
Suppress new "may be used uninitialized" warning.
Buildfarm member mamba fails to deduce that the function never uses this
variable without initializing it. Back-patch to v12, like commit b412f402d1e020c5dac94f3bf4a005db69519b99.
Noah Misch [Sat, 2 Nov 2024 16:04:55 +0000 (09:04 -0700)]
Move I/O before the index_update_stats() buffer lock region.
Commit a07e03fd8fa7daf4d1356f7cb501ffe784ea6257 enlarged the work done
here under the pg_class heap buffer lock. Two preexisting actions are
best done before holding that lock. Both RelationGetNumberOfBlocks()
and visibilitymap_count() do I/O, and the latter might exclusive-lock a
visibility map buffer. Moving these reduces contention and risk of
undetected LWLock deadlock. Back-patch to v12, like that commit.
This reverts commit 95c5acb3fc261067ab65ddc0b2dca8e162f09442 (v17) and
counterparts in each other non-master branch. If released, that commit
would have caused a worst-in-years minor release regression, via
undetected LWLock self-deadlock. This commit and its self-deadlock fix
warrant more bake time in the master branch.
Noah Misch [Sat, 2 Nov 2024 16:04:59 +0000 (09:04 -0700)]
Revert "WAL-log inplace update before revealing it to other sessions."
This reverts commit bfd5c6e279c8e1702eea882439dc7ebdf4d4b3a5 (v17) and
counterparts in each other non-master branch. This unblocks reverting a
commit on which it depends.
Álvaro Herrera [Wed, 30 Oct 2024 09:54:03 +0000 (10:54 +0100)]
Fix some more bugs in foreign keys connecting partitioned tables
* In DetachPartitionFinalize() we were applying a tuple conversion map
to tuples that didn't need one, which can lead to erratic behavior if
a partitioned table has a partition with a different column order, as
reported by Alexander Lakhin. This was introduced by 53af9491a043.
Don't do that. Also, modify a recently added test case to exercise
this.
* The same function as well as CloneFkReferenced() were acquiring
AccessShareLock on a partition, only to have CreateTrigger() later
acquire ShareRowExclusiveLock on it. This can lead to deadlock by
lock escalation, unnecessarily. Avoid that by acquiring the stronger
lock to begin with. This probably dates back to branch 12, but I have
never seen a report of this being a problem in the field.
* Innocuous but wasteful: also introduced by 53af9491a043, we were
reading a pg_constraint tuple from syscache that we don't need, as
reported by Tender Wang. Don't.
Noah Misch [Tue, 29 Oct 2024 16:39:55 +0000 (09:39 -0700)]
Unpin buffer before inplace update waits for an XID to end.
Commit a07e03fd8fa7daf4d1356f7cb501ffe784ea6257 changed inplace updates
to wait for heap_update() commands like GRANT TABLE and GRANT DATABASE.
By keeping the pin during that wait, a sequence of autovacuum workers
and an uncommitted GRANT starved one foreground LockBufferForCleanup()
for six minutes, on buildfarm member sarus. Prevent, at the cost of a
bit of complexity. Back-patch to v12, like the earlier commit. That
commit and heap_inplace_lock() have not yet appeared in any release.
Tom Lane [Tue, 29 Oct 2024 15:49:38 +0000 (11:49 -0400)]
Update time zone data files to tzdata release 2024b.
Historical corrections for Mexico, Mongolia, and Portugal.
Notably, Asia/Choibalsan is now an alias for Asia/Ulaanbaatar
rather than being a separate zone, mainly because the differences
between those zones were found to be based on untrustworthy data.
Michael Paquier [Tue, 29 Oct 2024 06:35:19 +0000 (15:35 +0900)]
doc: Add better description for rewrite functions in event triggers
There are two functions that can be used in event triggers to get more
details about a rewrite happening on a relation. Both had a limited
documentation:
- pg_event_trigger_table_rewrite_reason() and
pg_event_trigger_table_rewrite_oid() were not mentioned in the main
event trigger section in the paragraph dedicated to the event
table_rewrite.
- pg_event_trigger_table_rewrite_reason() returns an integer which is a
bitmap of the reasons why a rewrite happens. There was no explanation
about the meaning of these values, forcing the reader to look at the
code to find out that these are defined in event_trigger.h.
While on it, let's add a comment in event_trigger.h where the
AT_REWRITE_* are defined, telling to update the documentation when
these values are changed.
Backpatch down to 13 as a consequence of 1ad23335f36b, where this area
of the documentation has been heavily reworked.
David Rowley [Tue, 29 Oct 2024 03:25:29 +0000 (16:25 +1300)]
Doc: clarify enable_indexscan=off also disabled Index Only Scans
Disabling enable_indexscan has always also disabled Index Only Scans.
Here we make that more clear in the documentation in an attempt to
prevent future complaints complaining about this expected behavior.
Reported-by: Melanie Plageman
Author: David G. Johnston, David Rowley
Backpatch-through: 12, oldest supported version
Discussion: https://postgr.es/m/CAAKRu_atV=kovgpaLREyG68PB5+ncKvJ2UNoeRetEgyC3Yb5Sw@mail.gmail.com
Tom Lane [Mon, 28 Oct 2024 18:33:55 +0000 (14:33 -0400)]
Guard against enormously long input in pg_saslprep().
Coverity complained that pg_saslprep() could suffer integer overflow,
leading to under-allocation of the output buffer, if the input string
exceeds SIZE_MAX/4. This hazard seems largely hypothetical, but it's
easy enough to defend against, so let's do so.
This patch creates a third place in src/common/ where we are locally
defining MaxAllocSize so that we can test against that in the same way
in backend and frontend compiles. That seems like about two places
too many, so the next patch will move that into common/fe_memutils.h.
I'm hesitant to do that in back branches however.
Back-patch to v14. The code looks similar in older branches, but
before commit 67a472d71 there was a separate test on the input string
length that prevented this hazard.
Fix overflow in bsearch_arg() with more than INT_MAX elements
This was introduced in commit bfa2cee784, which replaced the old
bsearch_cmp() function we had in extended_stats.c with the current
implementation. The original discussion or commit message of bfa2cee784 didn't mention where the new implementation came from, but
based on some googling, I'm guessing *BSD or libiberty, all of which
share this same code, with or without this fix.
Noah Misch [Fri, 25 Oct 2024 13:51:03 +0000 (06:51 -0700)]
WAL-log inplace update before revealing it to other sessions.
A buffer lock won't stop a reader having already checked tuple
visibility. If a vac_update_datfrozenid() and then a crash happened
during inplace update of a relfrozenxid value, datfrozenxid could
overtake relfrozenxid. That could lead to "could not access status of
transaction" errors. Back-patch to v12 (all supported versions). In
v14 and earlier, this also back-patches the assertion removal from
commit 7fcf2faf9c7dd473208fd6d5565f88d7f733782b.
Noah Misch [Fri, 25 Oct 2024 13:51:02 +0000 (06:51 -0700)]
For inplace update, send nontransactional invalidations.
The inplace update survives ROLLBACK. The inval didn't, so another
backend's DDL could then update the row without incorporating the
inplace update. In the test this fixes, a mix of CREATE INDEX and ALTER
TABLE resulted in a table with an index, yet relhasindex=f. That is a
source of index corruption. Back-patch to v12 (all supported versions).
The back branch versions don't change WAL, because those branches just
added end-of-recovery SIResetAll(). All branches change the ABI of
extern function PrepareToInvalidateCacheTuple(). No PGXN extension
calls that, and there's no apparent use case in extensions.
Reviewed by Nitin Motiani and (in earlier versions) Andres Freund.
Noah Misch [Fri, 25 Oct 2024 13:51:06 +0000 (06:51 -0700)]
At end of recovery, reset all sinval-managed caches.
An inplace update's invalidation messages are part of its transaction's
commit record. However, the update survives even if its transaction
aborts or we stop recovery before replaying its transaction commit.
After recovery, a backend that started in recovery could update the row
without incorporating the inplace update. That could result in a table
with an index, yet relhasindex=f. That is a source of index corruption.
This bulk invalidation avoids the functional consequences. A future
change can fix the !RecoveryInProgress() scenario without changing the
WAL format. Back-patch to v17 - v12 (all supported versions). v18 will
instead add invalidations to WAL.
Noah Misch [Thu, 24 Oct 2024 16:16:14 +0000 (09:16 -0700)]
Stop reading uninitialized memory in heap_inplace_lock().
Stop computing a never-used value. This removes the read; the read had
no functional implications. Back-patch to v12, like commit a07e03fd8fa7daf4d1356f7cb501ffe784ea6257.
Amit Langote [Wed, 23 Oct 2024 08:54:48 +0000 (17:54 +0900)]
Remove unnecessary word in a comment
Relations opened by the executor are only closed once in
ExecCloseRangeTableRelations(), so the word "again" in the comment
for ExecGetRangeTableRelation() is misleading and unnecessary.
Michael Paquier [Tue, 22 Oct 2024 23:35:04 +0000 (08:35 +0900)]
ecpg: Fix out-of-bound read in DecodeDateTime()
It was possible for the code to read out-of-bound data from the
"day_tab" table with some crafted input data. Let's treat these as
invalid input as the month number is incorrect.
A test is added to test this case with a check on the errno returned by
the decoding routine. A test close to the new one added in this commit
was testing for a failure, but did not look at the errno generated, so
let's use this commit to also change it, adding a check on the errno
returned by DecodeDateTime().
Like the other test scripts, dt_test should likely be expanded to
include more checks based on the errnos generated in these code paths.
This is left as future work.
This issue exists since 2e6f97560a83, so backpatch all the way down.
Reported-by: Pavel Nekrasov
Author: Bruce Momjian, Pavel Nekrasov
Discussion: https://postgr.es/m/18614-6bbe00117352309e@postgresql.org
Backpatch-through: 12
Álvaro Herrera [Tue, 22 Oct 2024 14:01:18 +0000 (16:01 +0200)]
Restructure foreign key handling code for ATTACH/DETACH
... to fix bugs when the referenced table is partitioned.
The catalog representation we chose for foreign keys connecting
partitioned tables (in commit f56f8f8da6af) is inconvenient, in the
sense that a standalone table has a different way to represent the
constraint when referencing a partitioned table, than when the same
table becomes a partition (and vice versa). Because of this, we need to
create additional catalog rows on detach (pg_constraint and pg_trigger),
and remove them on attach. We were doing some of those things, but not
all of them, leading to missing catalog rows in certain cases.
The worst problem seems to be that we are missing action triggers after
detaching a partition, which means that you could update/delete rows
from the referenced partitioned table that still had referencing rows on
that table, the server failing to throw the required errors.
!!!
Note that this means existing databases with FKs that reference
partitioned tables might have rows that break relational integrity, on
tables that were once partitions on the referencing side of the FK.
Another possible problem is that trying to reattach a table
that had been detached would fail indicating that internal triggers
cannot be found, which from the user's point of view is nonsensical.
In branches 15 and above, we fix this by creating a new helper function
addFkConstraint() which is in charge of creating a standalone
pg_constraint row, and repurposing addFkRecurseReferencing() and
addFkRecurseReferenced() so that they're only the recursive routine for
each side of the FK, and they call addFkConstraint() to create
pg_constraint at each partitioning level and add the necessary triggers.
These new routines can be used during partition creation, partition
attach and detach, and foreign key creation. This reduces redundant
code and simplifies the flow.
In branches 14 and 13, we have a much simpler fix that consists on
simply removing the constraint on detach. The reason is that those
branches are missing commit f4566345cf40, which reworked the way this
works in a way that we didn't consider back-patchable at the time.
We opted to leave branch 12 alone, because it's different from branch 13
enough that the fix doesn't apply; and because it is going in EOL mode
very soon, patching it now might be worse since there's no way to undo
the damage if it goes wrong.
Existing databases might need to be repaired.
In the future we might want to rethink the catalog representation to
avoid this problem, but for now the code seems to do what's required to
make the constraints operate correctly.
Co-authored-by: Jehan-Guillaume de Rorthais <jgdr@dalibo.com> Co-authored-by: Tender Wang <tndrwang@gmail.com> Co-authored-by: Alvaro Herrera <alvherre@alvh.no-ip.org> Reported-by: Guillaume Lelarge <guillaume@lelarge.info> Reported-by: Jehan-Guillaume de Rorthais <jgdr@dalibo.com> Reported-by: Thomas Baehler (SBB CFF FFS) <thomas.baehler2@sbb.ch>
Discussion: https://postgr.es/m/20230420144344.40744130@karst
Discussion: https://postgr.es/m/20230705233028.2f554f73@karst
Discussion: https://postgr.es/m/GVAP278MB02787E7134FD691861635A8BC9032@GVAP278MB0278.CHEP278.PROD.OUTLOOK.COM
Discussion: https://postgr.es/m/18541-628a61bc267cd2d3@postgresql.org
Tom Lane [Mon, 21 Oct 2024 19:08:22 +0000 (15:08 -0400)]
Fix wrong assertion and poor error messages in "COPY (query) TO".
If the query is rewritten into a NOTIFY command by a DO INSTEAD
rule, we'd get an assertion failure, or in non-assert builds
issue a rather confusing error message. Improve that.
Also fix a longstanding grammar mistake in a nearby error message.
Per bug #18664 from Alexander Lakhin. Back-patch to all supported
branches.
Fix race condition in committing a serializable transaction
The finished transaction list can contain XIDs that are older than the
serializable global xmin. It's a short-lived state;
ClearOldPredicateLocks() removes any such transactions from the list,
and it's called whenever the global xmin advances. But if another
backend calls SummarizeOldestCommittedSxact() in that window, it will
call SerialAdd() on an XID that's older than the global xmin, or if
there are no more transactions running, when global xmin is
invalid. That trips the assertion in SerialAdd().
Fixes bug #18658 reported by Andrew Bille. Thanks to Alexander Lakhin
for analysis. Backpatch to all versions.
Álvaro Herrera [Sun, 20 Oct 2024 13:36:20 +0000 (15:36 +0200)]
Note that index_name in ALTER INDEX ATTACH PARTITION can be schema-qualified
Missed in 8b08f7d4820f; backpatch to all supported branches.
Reported-by: alvaro@datadoghq.com Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/172924785099.698.15236991344616673753@wrigleys.postgresql.org
Nathan Bossart [Fri, 18 Oct 2024 15:20:15 +0000 (10:20 -0500)]
Adjust documentation for configuring Linux huge pages.
The present wording about viewing shared_memory_size_in_huge_pages
seems to suggest that the parameter cannot be viewed after startup
at all, whereas the intent is to make it clear that you can't use
"postgres -C" to view this parameter while the server is running.
This commit rephrases this section to remove the ambiguity.
Author: Seino Yuki Reviewed-by: Michael Paquier, David G. Johnston, Fujii Masao
Discussion: https://postgr.es/m/420584fd274f9ec4f337da55ffb3b790%40oss.nttdata.com
Backpatch-through: 15
Thomas Munro [Thu, 17 Oct 2024 02:52:24 +0000 (15:52 +1300)]
Fix extreme skew detection in Parallel Hash Join.
After repartitioning the inner side of a hash join that would have
exceeded the allowed size, we check if all the tuples from a parent
partition moved to one child partition. That is evidence that it
contains duplicate keys and later attempts to repartition will also
fail, so we should give up trying to limit memory (for lack of a better
fallback strategy).
A thinko prevented the check from working correctly in partition 0 (the
one that is partially loaded into memory already). After
repartitioning, we should check for extreme skew if the *parent*
partition's space_exhausted flag was set, not the child partition's.
The consequence was repeated futile repartitioning until per-partition
data exceeded various limits including "ERROR: invalid DSA memory alloc
request size 1811939328", OS allocation failure, or temporary disk space
errors. (We could also do something about some of those symptoms, but
that's material for separate patches.)
This problem only became likely when PostgreSQL 16 introduced support
for Parallel Hash Right/Full Join, allowing NULL keys into the hash
table. Repartitioning always leaves NULL in partition 0, no matter how
many times you do it, because the hash value is all zero bits. That's
unlikely for other hashed values, but they might still have caused
wasted extra effort before giving up.
Back-patch to all supported releases.
Reported-by: Craig Milhiser <craig@milhiser.com> Reviewed-by: Andrei Lepikhov <lepihov@gmail.com>
Discussion: https://postgr.es/m/CA%2BwnhO1OfgXbmXgC4fv_uu%3DOxcDQuHvfoQ4k0DFeB0Qqd-X-rQ%40mail.gmail.com
Tom Lane [Wed, 16 Oct 2024 21:36:29 +0000 (17:36 -0400)]
Further refine _SPI_execute_plan's rule for atomic execution.
Commit 2dc1deaea turns out to have been still a brick shy of a load,
because CALL statements executing within a plpgsql exception block
could still pass the wrong snapshot to stable functions within the
CALL's argument list. That happened because standard_ProcessUtility
forces isAtomicContext to true if IsTransactionBlock is true, which
it always will be inside a subtransaction. Then ExecuteCallStmt
would think it does not need to push a new snapshot --- but
_SPI_execute_plan didn't do so either, since it thought it was in
nonatomic mode.
The best fix for this seems to be for _SPI_execute_plan to operate
in atomic execution mode if IsSubTransaction() is true, even when the
SPI context as a whole is non-atomic. This makes _SPI_execute_plan
have the same rules about when non-atomic execution is allowed as
_SPI_commit/_SPI_rollback have about when COMMIT/ROLLBACK are allowed,
which seems appropriately symmetric. (If anyone ever tries to allow
COMMIT/ROLLBACK inside a subtransaction, this would all need to be
rethought ... but I'm unconvinced that such a thing could be logically
consistent at all.)
For further consistency, also check IsSubTransaction() in
SPI_inside_nonatomic_context. That does not matter for its
one present-day caller StartTransaction, which can't be reached
inside a subtransaction. But if any other callers ever arise,
they'd presumably want this definition.
Per bug #18656 from Alexander Alehin. Back-patch to all
supported branches, like previous fixes in this area.
Masahiko Sawada [Wed, 16 Oct 2024 19:07:58 +0000 (12:07 -0700)]
Reduce memory block size for decoded tuple storage to 8kB.
Commit a4ccc1cef introduced the Generation Context and modified the
logical decoding process to use a Generation Context with a fixed
block size of 8MB for storing tuple data decoded during logical
decoding (i.e., rb->tup_context). Several reports have indicated that
the logical decoding process can be terminated due to
out-of-memory (OOM) situations caused by excessive memory usage in
rb->tup_context.
This issue can occur when decoding a workload involving several
concurrent transactions, including a long-running transaction that
modifies tuples. By design, the Generation Context does not free a
memory block until all chunks within that block are
released. Consequently, if tuples modified by the long-running
transaction are stored across multiple memory blocks, these blocks
remain allocated until the long-running transaction completes, leading
to substantial memory fragmentation. The memory usage during logical
decoding, tracked by rb->size, does not account for memory
fragmentation, resulting in potentially much higher memory consumption
than the value of the logical_decoding_work_mem parameter.
Various improvement strategies were discussed in the relevant
thread. This change reduces the block size of the Generation Context
used in rb->tup_context from 8MB to 8kB. This modification
significantly decreases the likelihood of substantial memory
fragmentation occurring and is relatively straightforward to
backport. Performance testing across multiple platforms has confirmed
that this change will not introduce any performance degradation that
would impact actual operation.
Backport to all supported branches.
Reported-by: Alex Richman, Michael Guissine, Avi Weinberg Reviewed-by: Amit Kapila, Fujii Masao, David Rowley Tested-by: Hayato Kuroda, Shlok Kyal
Discussion: https://postgr.es/m/CAD21AoBTY1LATZUmvSXEssvq07qDZufV4AF-OHh9VD2pC0VY2A%40mail.gmail.com
Backpatch-through: 12
Tom Lane [Sat, 12 Oct 2024 18:56:08 +0000 (14:56 -0400)]
Correctly identify which EC members are computable at a plan node.
find_computable_ec_member() had the wrong mental model of what
its primary caller prepare_sort_from_pathkeys() would do with
the selected EquivalenceClass member expression. We will not
compute the EC expression in a plan node atop the one returning
the passed-in targetlist; rather, the EC expression will be
computed as an additional column of that targetlist. So any
Var or quasi-Var used in the given tlist is also available to the
EC expression. In simple cases this makes no difference because
the given tlist is just a list of Vars or quasi-Vars --- but if
we are considering an appendrel member produced by flattening
a UNION ALL, the tlist may contain expressions, resulting in
failure to match and a "could not find pathkey item to sort"
error.
To fix, we can flatten both the tlist and the EC members with
pull_var_clause(), and then just check for subset-ness, so
that the code is actually shorter than before.
While this bug is quite old, the present patch only works back to
v13. We could possibly make it work in v12 by back-patching parts
of 375398244. On the whole though I don't like the risk/reward
ratio of that idea. v12's final release is next month, meaning
there would be no chance to correct matters if the patch causes a
regression. Since this failure has escaped notice for 14 years,
it's likely nobody will hit it in the field with v12.
Commit 149ac7d4559 which re-implemented pgindent in Perl explicitly
imported the devnull function from File::Spec, but the module does
not export anything. In recent versions of Perl calling a missing
import function cause a warning, which combined with warnings being
fatal cause pgindent to error out.
Backpatch to all supported versions.
Author: Erik Wienhold <ewie@ewie.name> Reviewed-by: Andrew Dunstan <andrew@dunslane.net> Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discusson: https://postgr.es/m/2372cd74-11b0-46f9-b28e-8f9627215d19@ewie.name
Backpatch-through: v12
The test was unstable in branches 14 and 15 as we were relying on the
number of changes in the table having a toast column to start streaming.
On branches >= 16, we have a GUC debug_logical_replication_streaming which
can stream each change, so the test was stable in those branches.
Change the test to use PREPARE TRANSACTION as that should make the result
consistent and test the code changed in 022564f60c.
Reported-by: Daniel Gustafsson as per buildfarm
Author: Hou Zhijie, Amit Kapila
Backpatch-through: 14
Discussion: https://postgr.es/m/8C2F86AA-981E-4803-B14D-E264C0255330@yesql.se
Nathan Bossart [Mon, 7 Oct 2024 21:49:20 +0000 (16:49 -0500)]
vacuumdb: Schema-qualify operator in catalog query's WHERE clause.
Commit 1ab67c9dfa, which modified this catalog query so that it
doesn't return temporary relations, forgot to schema-qualify the
operator. A comment earlier in the function implores us to fully
qualify everything in the query:
* Since we execute the constructed query with the default search_path
* (which could be unsafe), everything in this query MUST be fully
* qualified.
This commit fixes that. While at it, add a newline for consistency
with surrounding code.
Nathan Bossart [Mon, 7 Oct 2024 18:51:03 +0000 (13:51 -0500)]
Fix Y2038 issues with MyStartTime.
Several places treat MyStartTime as a "long", which is only 32 bits
wide on some platforms. In reality, MyStartTime is a pg_time_t,
i.e., a signed 64-bit integer. This will lead to interesting bugs
on the aforementioned systems in 2038 when signed 32-bit integers
are no longer sufficient to store Unix time (e.g., "pg_ctl start"
hanging). To fix, ensure that MyStartTime is handled as a 64-bit
value everywhere. (Of course, users will need to ensure that
time_t is 64 bits wide on their system, too.)
Co-authored-by: Max Johnson
Discussion: https://postgr.es/m/CO1PR07MB905262E8AC270FAAACED66008D682%40CO1PR07MB9052.namprd07.prod.outlook.com
Backpatch-through: 12
Amit Kapila [Mon, 7 Oct 2024 09:23:18 +0000 (14:53 +0530)]
Fix fetching default toast value during decoding of in-progress transactions.
During logical decoding of in-progress transactions, we perform the toast
table scan while fetching the default toast value for an attribute. We
forgot to initialize the flag during this scan to indicate that the system
table scan is in progress. We need this flag to ensure that during logical
decoding we never directly access the tableam or heap APIs because we check
for concurrent aborts only in systable_* APIs.
Reported-by: Alexander Lakhin
Author: Takeshi Ideriha, Hou Zhijie Reviewed-by: Amit Kapila, Hou Zhijie
Backpatch-through: 14
Discussion: https://postgr.es/m/18641-6687273b7f15269d@postgresql.org
Tom Lane [Sun, 6 Oct 2024 20:03:48 +0000 (16:03 -0400)]
Ignore not-yet-defined Portals in pg_cursors view.
pg_cursor() supposed that any Portal it finds in the hash table must
have sourceText set up, but there's an edge case where that is not so.
A newly-created Portal has sourceText = NULL, and that doesn't change
until PortalDefineQuery is called. In SPI_cursor_open_internal,
we perform GetCachedPlan between CreatePortal and PortalDefineQuery,
and it's possible for user-defined code to execute during that
planning and cause a fetch from the pg_cursors view, resulting in a
null-pointer-dereference crash. (It looks like the same could happen
in exec_bind_message, but I've not tried to provoke a failure there.)
I considered trying to fix this by setting sourceText sooner, but
there may be instances of this same calling pattern in extensions,
and we couldn't be sure they'd get the memo promptly. It seems
better to redefine pg_cursor as not showing Portals that have
not yet had PortalDefineQuery called on them, which we can do by
just skipping them if sourceText is still NULL.
(Before a1c692358, pg_cursor would instead return a row with NULL
in the statement column. We could revert to that behavior but it
doesn't really seem like a better definition, especially since our
documentation doesn't suggest that the column could be NULL.)
Per report from PetSerAl. Back-patch to all supported branches.
Tom Lane [Wed, 2 Oct 2024 21:30:36 +0000 (17:30 -0400)]
Parse libpq's "keepalives" option more like other integer options.
Use pqParseIntParam (nee parse_int_param) instead of using strtol
directly. This allows trailing whitespace, which the previous coding
didn't, and makes the spelling of the error message consistent with
other similar cases.
This seems to be an oversight in commit e7a221797, which introduced
parse_int_param. That fixed places that were using atoi(), but missed
this place which was randomly using strtol() instead.
Ordinarily I'd consider this minor cleanup not worth back-patching.
However, it seems that ecpg assumes it can add trailing whitespace
to URL parameters, so that use of the keepalives option fails in
that context. Perhaps that's worth improving as a separate matter.
In the meantime, back-patch this to all supported branches.
Michael Paquier [Tue, 1 Oct 2024 06:44:11 +0000 (15:44 +0900)]
Fix race condition in COMMIT PREPARED causing orphaned 2PC files
COMMIT PREPARED removes on-disk 2PC files near its end, but the state
checked if a file is on-disk or not gets read from shared memory while
not holding the two-phase state lock.
Because of that, there was a small window where a second backend doing a
PREPARE TRANSACTION could reuse the GlobalTransaction put back into the
2PC free list by the COMMIT PREPARED, overwriting the "ondisk" flag read
afterwards by the COMMIT PREPARED to decide if its on-disk two-phase
state file should be removed, preventing the file deletion.
This commit fixes this issue so as the "ondisk" flag in the
GlobalTransaction is read while holding the two-phase state lock, not
from shared memory after its entry has been added to the free list.
Orphaned two-phase state files flushed to disk after a checkpoint are
discarded at the beginning of recovery. However, a truncation of
pg_xact/ would make the startup process issue a FATAL when it cannot
read the SLRU page holding the state of the transaction whose 2PC file
was orphaned, which is a necessary step to decide if the 2PC file should
be removed or not. Removing manually the file would be necessary in
this case.
Issue introduced by effe7d9552dd, so backpatch all the way down.
Andrew Dunstan [Mon, 30 Sep 2024 15:32:32 +0000 (11:32 -0400)]
Bump MIN_WINNT for MINGW to clear a build error
Because we have been setting this too low, there has been a
long-standing warning about a missing declaration for inet_pton().
Modern gcc now considers this an error, so we have been getting failures
on the buildfarm animal fairywren.
Fix suggested by Thomas Munro.
This isn't needed in later branches, as they already set MIN_WINNT
higher, nor on earlier branches because they don't use inet_pton().
reindexdb: Skip reindexing temporary tables and indexes.
Reindexing temp tables or indexes of other sessions is not allowed.
However, reindexdb in parallel mode previously listed them as
the objects to process, leading to failures.
This commit ensures reindexdb in parallel mode skips temporary tables
and indexes by adding a condition based on the relpersistence column
in pg_class to the object listing queries, preventing these issues.
Note that this commit does not affect reindexdb when temporary tables
or indexes are explicitly specified using the -t or -j options;
reindexdb in that case still does not skip them and can cause an error.
Back-patch to v13 where parallel mode was introduced in reindexdb.
Author: Fujii Masao Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/5f37ee56-14fb-44fe-9150-9eb97e10538b@oss.nttdata.com
Remove NULL dereference from RenameRelationInternal().
Defect in last week's commit aac2c9b4fde889d13f859c233c2523345e72d32b,
per Coverity. Reaching this would need catalog corruption. Back-patch
to v12, like that commit.
Michael Paquier [Fri, 27 Sep 2024 00:40:18 +0000 (09:40 +0900)]
Fix incorrect memory access in VACUUM FULL with invalid toast indexes
An invalid toast index is skipped in reindex_relation(). These would be
remnants of a failed REINDEX CONCURRENTLY and they should never been
rebuilt as there can only be one valid toast index at a time.
REINDEX_REL_SUPPRESS_INDEX_USE, used by CLUSTER and VACUUM FULL, needs
to maintain a list of the indexes being processed. The list of indexes
is retrieved from the relation cache, and includes invalid indexes. The
code has missed that invalid toast indexes are ignored in
reindex_relation() as this leads to a hard failure in reindex_index(),
and they were left in the reindex pending list, making the list
inconsistent when rechecked. The incorrect memory access was happening
when scanning pg_class for the refresh of pg_database.datfrozenxid, when
doing a scan of pg_class.
This issue exists since REINDEX CONCURRENTLY exists, where invalid toast
indexes can exist, so backpatch all the way down.
Reported-by: Alexander Lakhin
Author: Tender Wang
Discussion: https://postgr.es/m/18630-9aed99c38830657d@postgresql.org
Backpatch-through: 12
Andres Freund [Wed, 5 Oct 2022 17:44:38 +0000 (10:44 -0700)]
tests: Restrict pg_locks queries in advisory_locks.sql to current database
Otherwise testing an existing installation can fail, if there are other locks,
e.g. from one of the isolation tests.
This was originally applied as c3315a7da57b in 16~, but it is possible
to see this test fail depending on the concurrent activity for older
active branches.
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/20221003234111.4ob7yph6r4g4ywhu@awork3.anarazel.de
Backpatch-through: 12
Michael Paquier [Wed, 25 Sep 2024 05:44:56 +0000 (14:44 +0900)]
vacuumdb: Skip temporary tables in query to build list of relations
Running vacuumdb with a non-superuser while another user has created a
temporary table would lead to a mid-flight permission failure,
interrupting the operation. vacuum_rel() skips temporary relations of
other backends, and it makes no sense for vacuumdb to know about these
relations, so let's switch it to ignore temporary relations entirely.
Adding a qual in the query based on relpersistence simplifies the
generation of its WHERE clause in vacuum_one_database(), per se the
removal of "has_where".
For inplace update durability, make heap_update() callers wait.
The previous commit fixed some ways of losing an inplace update. It
remained possible to lose one when a backend working toward a
heap_update() copied a tuple into memory just before inplace update of
that tuple. In catalogs eligible for inplace update, use LOCKTAG_TUPLE
to govern admission to the steps of copying an old tuple, modifying it,
and issuing heap_update(). This includes MERGE commands. To avoid
changing most of the pg_class DDL, don't require LOCKTAG_TUPLE when
holding a relation lock sufficient to exclude inplace updaters.
Back-patch to v12 (all supported versions). In v13 and v12, "UPDATE
pg_class" or "UPDATE pg_database" can still lose an inplace update. The
v14+ UPDATE fix needs commit 86dc90056dfdbd9d1b891718d2e5614e3e432f35,
and it wasn't worth reimplementing that fix without such infrastructure.
Reviewed by Nitin Motiani and (in earlier versions) Heikki Linnakangas.
Fix data loss at inplace update after heap_update().
As previously-added tests demonstrated, heap_inplace_update() could
instead update an unrelated tuple of the same catalog. It could lose
the update. Losing relhasindex=t was a source of index corruption.
Inplace-updating commands like VACUUM will now wait for heap_update()
commands like GRANT TABLE and GRANT DATABASE. That isn't ideal, but a
long-running GRANT already hurts VACUUM progress more just by keeping an
XID running. The VACUUM will behave like a DELETE or UPDATE waiting for
the uncommitted change.
For implementation details, start at the systable_inplace_update_begin()
header comment and README.tuplock. Back-patch to v12 (all supported
versions). In back branches, retain a deprecated heap_inplace_update(),
for extensions.
Reported by Smolkin Grigory. Reviewed by Nitin Motiani, (in earlier
versions) Heikki Linnakangas, and (in earlier versions) Alexander
Lakhin.
Warn if LOCKTAG_TUPLE is held at commit, under debug_assertions.
The current use always releases this locktag. A planned use will
continue that intent. It will involve more areas of code, making unlock
omissions easier. Warn under debug_assertions, like we do for various
resource leaks. Back-patch to v12 (all supported versions), the plan
for the commit of the new use.
Project policy is to not leave global objects behind after a regress
test run. This was found as a result of the development of a patch
to make pg_regress detect such leftovers automatically, which in the
end was withdrawn due to issues with parallel runs.
This was originally committed as 936e3fa3787a, but the issue also exists
in the 12~16 range.
Don't enter parallel mode when holding interrupts.
Doing so caused the leader to hang in wait_event=ParallelFinish, which
required an immediate shutdown to resolve. Back-patch to v12 (all
supported versions).
Michael Paquier [Wed, 18 Sep 2024 00:59:23 +0000 (09:59 +0900)]
Add missing query ID reporting in extended query protocol
This commit adds query ID reports for two code paths when processing
extended query protocol messages:
- When receiving a bind message, setting it to the first Query retrieved
from a cached cache.
- When receiving an execute message, setting it to the first PlannedStmt
stored in a portal.
An advantage of this method is that this is able to cover all the types
of portals handled in the extended query protocol, particularly these
two when the report done in ExecutorStart() is not enough (neither is an
addition in ExecutorRun(), actually, for the second point):
- Multiple execute messages, with multiple ExecutorRun().
- Portal with execute/fetch messages, like a query with a RETURNING
clause and a fetch size that stores the tuples in a first execute
message going though ExecutorStart() and ExecuteRun(), followed by one
or more execute messages doing only fetches from the tuplestore created
in the first message. This corresponds to the case where
execute_is_fetch is set, for example.
Note that the query ID reporting done in ExecutorStart() is still
necessary, as an EXECUTE requires it. Query ID reporting is optimistic
and more calls to pgstat_report_query_id() don't matter as the first
report takes priority except if the report is forced. The comment in
ExecutorStart() is adjusted to reflect better the reality with the
extended query protocol.
The test added in pg_stat_statements is a courtesy of Robert Haas. This
uses psql's \bind metacommand, hence this part is backpatched down to
v16.
Reported-by: Kaido Vaikla, Erik Wienhold
Author: Sami Imseih Reviewed-by: Jian He, Andrei Lepikhov, Michael Paquier
Discussion: https://postgr.es/m/CA+427g8DiW3aZ6pOpVgkPbqK97ouBdf18VLiHFesea2jUk3XoQ@mail.gmail.com
Discussion: https://postgr.es/m/CA+TgmoZxtnf_jZ=VqBSyaU8hfUkkwoJCJ6ufy4LGpXaunKrjrg@mail.gmail.com
Discussion: https://postgr.es/m/1391613709.939460.1684777418070@office.mailbox.org
Backpatch-through: 14
Tom Lane [Tue, 17 Sep 2024 19:53:26 +0000 (15:53 -0400)]
Repair pg_upgrade for identity sequences with non-default persistence.
Since we introduced unlogged sequences in v15, identity sequences
have defaulted to having the same persistence as their owning table.
However, it is possible to change that with ALTER SEQUENCE, and
pg_dump tries to preserve the logged-ness of sequences when it doesn't
match (as indeed it wouldn't for an unlogged table from before v15).
The fly in the ointment is that ALTER SEQUENCE SET [UN]LOGGED fails
in binary-upgrade mode, because it needs to assign a new relfilenode
which we cannot permit in that mode. Thus, trying to pg_upgrade a
database containing a mismatching identity sequence failed.
To fix, add syntax to ADD/ALTER COLUMN GENERATED AS IDENTITY to allow
the sequence's persistence to be set correctly at creation, and use
that instead of ALTER SEQUENCE SET [UN]LOGGED in pg_dump. (I tried to
make SET [UN]LOGGED work without any pg_dump modifications, but that
seems too fragile to be a desirable answer. This way should be
markedly faster anyhow.)
In passing, document the previously-undocumented SEQUENCE NAME option
that pg_dump also relies on for identity sequences; I see no value
in trying to pretend it doesn't exist.
Per bug #18618 from Anthony Hsu.
Back-patch to v15 where we invented this stuff.
Tom Lane [Sun, 15 Sep 2024 17:33:09 +0000 (13:33 -0400)]
Replace usages of xmlXPathCompile() with xmlXPathCtxtCompile().
In existing releases of libxml2, xmlXPathCompile can be driven
to stack overflow because it fails to protect itself against
too-deeply-nested input. While there is an upstream fix as of
yesterday, it will take years for that to propagate into all
shipping versions. In the meantime, we can protect our own
usages basically for free by calling xmlXPathCtxtCompile instead.
(The actual bug is that libxml2 keeps its nesting counter in the
xmlXPathContext, and its parsing code was willing to just skip
counting nesting levels if it didn't have a context. So if we supply
a context, all is well. It seems odd actually that it works at all
to not supply a context, because this means that XPath parsing does
not have access to XML namespace info. Apparently libxml2 never
checks namespaces until runtime? Anyway, this seems like good
future-proofing even if its only immediate effect is to dodge a bug.)
Sadly, this hack only offers protection with libxml2 2.9.11 and newer.
Before that there are multiple similar problems, so if you are
processing untrusted XML it behooves you to get a newer version.
But we have some pretty old libxml2 in the buildfarm, so it seems
impractical to add a regression test to verify this fix.
Per bug #18617 from Jingzhou Fu. Back-patch to all supported
versions.
Tom Lane [Sat, 14 Sep 2024 21:55:03 +0000 (17:55 -0400)]
Run regression tests with timezone America/Los_Angeles.
Historically we've used timezone "PST8PDT", but the recent release
2024b of tzdb changes the definition of that zone in a way that
breaks many test cases concerned with dates before 1970. Although
we've not yet adopted 2024b into our own tree, this is already
problematic for people using --with-system-tzdata if their platform
has already adopted 2024b. To work with both older and newer
versions of tzdb, switch to using "America/Los_Angeles", accepting
the ensuing changes in regression test results.
Andrew Dunstan [Sat, 14 Sep 2024 12:37:08 +0000 (08:37 -0400)]
Only define NO_THREAD_SAFE_LOCALE for MSVC plperl when required
Latest versions of Strawberry Perl define USE_THREAD_SAFE_LOCALE, and we
therefore get a handshake error when building against such instances.
The solution is to perform a test to see if USE_THREAD_SAFE_LOCALE is
defined and only define NO_THREAD_SAFE_LOCALE if it isn't.
Backpatch the meson.build fix back to release 16 and apply the same
logic to Mkvcbuild.pm in releases 12 through 16.
Original report of the issue from Muralikrishna Bandaru.
Tom Lane [Fri, 13 Sep 2024 20:16:47 +0000 (16:16 -0400)]
Allow _h_indexbuild() to be interrupted.
When we are building a hash index that is large enough to need
pre-sorting (larger than either maintenance_work_mem or NBuffers),
the initial sorting phase is interruptible, but the insertion
phase wasn't. Add the missing CHECK_FOR_INTERRUPTS().
Per bug #18616 from Alexander Lakhin. Back-patch to all
supported branches.
I managed to break this test in two different ways in commit 05036a3155.
First, the output of the new call to tuple_data_split() on the test
sequence is dependent on endianness. This is fixed by setting a
special start value for the test sequence that produces the same
output regardless of the endianness of the machine.
Second, on versions older than v15, the new test case fails under
"force_parallel_mode = regress" with the following error:
ERROR: cannot access temporary tables during a parallel operation
This is because pageinspect's disk-accessing functions are
incorrectly marked PARALLEL SAFE on versions older than v15 (see
commit aeaaf520f4 for details). This one is fixed by changing the
test sequence to be permanent. The only reason it was previously
marked temporary was to avoid needing a DROP SEQUENCE command at
the end of the test. Unlike some other tests in this file, the use
of a permanent sequence here shouldn't result in any test
instability like what was fixed by commit e2933a6e11.
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/ZuOKOut5hhDlf_bP%40nathan
Backpatch-through: 12
Reintroduce support for sequences in pgstattuple and pageinspect.
Commit 4b82664156 restricted a number of functions provided by
contrib modules to only relations that use the "heap" table access
method. Sequences always use this table access method, but they do
not advertise as such in the pg_class system catalog, so the
aforementioned commit also (presumably unintentionally) removed
support for sequences from some of these functions. This commit
reintroduces said support for sequences to these functions and adds
a couple of relevant tests.
Co-authored-by: Ayush Vatsa Reviewed-by: Robert Haas, Michael Paquier, Matthias van de Meent
Discussion: https://postgr.es/m/CACX%2BKaP3i%2Bi9tdPLjF5JCHVv93xobEdcd_eB%2B638VDvZ3i%3DcQA%40mail.gmail.com
Backpatch-through: 12
Tom Lane [Wed, 11 Sep 2024 15:41:47 +0000 (11:41 -0400)]
Remove incorrect Assert.
check_agglevels_and_constraints() asserted that if we find an
aggregate function in an EXPR_KIND_FROM_SUBSELECT expression, the
expression must be in a LATERAL subquery. Alexander Lakhin found a
case where that's not so: because of the odd scoping rules for NEW/OLD
within a rule, a reference to NEW/OLD could cause an aggregate to be
considered top-level even though it's in an unmarked sub-select.
The error message that would be thrown seems sufficiently on-point,
so just remove the Assert. (Hence, this is not a bug for production
builds.)
This Assert was added by me in commit eaccfded9 (9.3 era). It looks
like I put it in to cross-check that the new logic for detecting
misplaced aggregates (using agglevelsup) caught the same cases that a
previous check on p_lateral_active did. So there might have been some
related misbehavior before eaccfded9 ... but that's very ancient
history by now, so I didn't dig any deeper.
Per bug #18608 from Alexander Lakhin. Back-patch to all supported
branches.
Michael Paquier [Mon, 9 Sep 2024 04:50:12 +0000 (13:50 +0900)]
Fix waits of REINDEX CONCURRENTLY for indexes with predicates or expressions
As introduced by f9900df5f94, a REINDEX CONCURRENTLY job done for an
index with predicates or expressions would set PROC_IN_SAFE_IC in its
MyProc->statusFlags, causing it to be ignored by other concurrent
operations.
Such concurrent index rebuilds should never be ignored, as a predicate
or an expression could call a user-defined function that accesses a
different table than the table where the index is rebuilt.
A test that uses injection points is added, backpatched down to 17.
Michail has proposed a different test, but I have added something
simpler with more coverage.
Tom Lane [Thu, 5 Sep 2024 16:42:33 +0000 (12:42 -0400)]
Prevent mis-encoding of "trailing junk after numeric literal" errors.
Since commit 2549f0661, we reject an identifier immediately following
a numeric literal (without separating whitespace), because that risks
ambiguity with hex/octal/binary integers. However, that patch used
token patterns like "{integer}{ident_start}", which is problematic
because {ident_start} matches only a single byte. If the first
character after the integer is a multibyte character, this ends up
with flex reporting an error message that includes a partial multibyte
character. That can cause assorted bad-encoding problems downstream,
both in the report to the client and in the postmaster log file.
To fix, use {identifier} not {ident_start} in the "junk" token
patterns, so that they will match complete multibyte characters.
This seems generally better user experience quite aside from the
encoding problem: for "123abc" the error message will now say that
the error appeared at or near "123abc" instead of "123a".
While at it, add some commentary about why these patterns exist
and how they work.
Report and patch by Karina Litskevich; review by Pavel Borisov.
Back-patch to v15 where the problem came in.
Thomas Munro [Sat, 31 Aug 2024 02:32:08 +0000 (14:32 +1200)]
Stabilize 039_end_of_wal test.
The first test was sensitive to the insert LSN after setting up the
catalogs, which depended on environmental things like the locales on the
OS and usernames. Switch to a new WAL file before the first test, as a
simple way to put every computer into the same state.
Back-patch to all supported releases.
Reported-by: Anton Voloshin <a.voloshin@postgrespro.ru> Reported-by: Nathan Bossart <nathandbossart@gmail.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Nathan Bossart <nathandbossart@gmail.com>
Discussion: https://postgr.es/m/b26aeac2-cb6d-4633-a7ea-945baae83dcf%40postgrespro.ru
Peter Eisentraut [Thu, 29 Aug 2024 06:38:29 +0000 (08:38 +0200)]
Disallow USING clause when altering type of generated column
This does not make sense. It would write the output of the USING
clause into the converted column, which would violate the generation
expression. This adds a check to error out if this is specified.
There was a test for this, but that test errored out for a different
reason, so it was not effective.
Reported-by: Jian He <jian.universality@gmail.com> Reviewed-by: Yugo NAGATA <nagata@sraoss.co.jp>
Discussion: https://www.postgresql.org/message-id/flat/c7083982-69f4-4b14-8315-f9ddb20b9834%40eisentraut.org