DST law changes in Chile: there is a new time zone America/Coyhaique
for Chile's Aysén Region, to account for it changing to UTC-03
year-round and thus diverging from America/Santiago.
Historical corrections for Iran.
Backpatch-through: 13
This reverts commit 38da053463, which
attempted to preserve our ability to start with only 60 semaphores.
Subsequent changes (particularly 55b454d0e) have put that idea pretty
much permanently out of reach: people wishing to use Postgres v18 on
OpenBSD or NetBSD will have no choice but to increase those platforms'
default values of SEMMNI and SEMMNS.
Hence, revert 38da05346's changes in SEMAS_PER_SET and the minimum
tested value of max_connections. Adjust a comment from the subsequent
patch 6d0154196, and tweak the wording in runtime.sgml to make it
clear that changing SEMMNI/SEMMNS is no longer even a little bit
optional on these platforms.
Although 38da05346 was later back-patched into v17, leave that branch
alone: it's still capable of starting with 60 semaphores, and there's
no reason to break that.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Nathan Bossart <nathandbossart@gmail.com>
Discussion: https://postgr.es/m/E1tuZNv-0037Gs-34@gemulon.postgresql.org
Discussion: https://postgr.es/m/1052019.1745947915@sss.pgh.pa.us
Tell UIs to hide the value of oauth_client_secret, like the other
passwords. Due to the previous commit, this does not affect postgres_fdw
and dblink, but add a comment to try to warn others of the hazard in the
future.
Reported-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/20250415191435.55.nmisch%40google.com
Commit 6d01541960 taught initdb to lower the default value of
autovacuum_worker_slots for systems with very few semaphores. It
also added a "fake" report for the chosen value, i.e., initdb
prints a message about selecting the default, but the value was
already selected in a previous test. Per discussion, this is not a
precedent we want to set, and it seems unnecessary to report
everything derived from max_connections, so let's remove the "fake"
report.
Reported-by: Peter Eisentraut <peter@eisentraut.org>
Suggested-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/de722583-4ba4-4063-bc41-e20684978116%40eisentraut.org
This commit fixes two bug in ChangeVarNodes_walker() function.
* When considering RestrictInfo, walk down to its clauses based on the
presense of relid to be deleted not just in clause_relids but also in
required_relids.
* Incrementally adjust num_base_rels based on the change of clause_relids
instead of recalculating it using clause_relids, which could contain
outer-join relids.
Reported-by: Richard Guo <guofenglinux@gmail.com>
Discussion: https://postgr.es/m/CAMbWs49PE3CvnV8vrQ0Dr%3DHqgZZmX0tdNbzVNJxqc8yg-8kDQQ%40mail.gmail.com
Author: Andrei Lepikhov <lepihov@gmail.com>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
The --help synopsis should only be one line. This rephrases the first
line a bit to reflect the new functionality of restoring multiple
databases from pg_dumpall output. Additional explanations are better
kept in the man page.
The slot synchronization skips updating the confirmed_flush LSN of the
local slot if the local slot has a newer catalog_xmin or restart_lsn, but
still allows updating the two_phase and two_phase_at fields of the slot.
This opens up a window for the prepared transactions between old
confirmed_flush LSN and two_phase_at to unexpectedly get decoded and sent
to the downstream after promotion. Then, while decoding the commit
prepared the assert will fail, which expects that the prepare hasn't been
sent to the downstream.
The fix is to skip updating the other slot fields when we are skipping to
update the confirmed_flush LSN of the slot.
We didn't backpatch this commit as two_phase_at was not synced in back
branches, which means prepared transactions won't be unexpectedly sent to
downstream.
We discovered this problem while analyzing BF failure reported in the
discussion link.
Reliably reproducing this issue without a debugger is difficult. Given
its rarity, adding specific injection point to test it doesn't seem
worthwhile, so we won't be adding a dedicated test case.
Author: Zhijie Hou <houzj.fnst@fujitsu.com>
Reviewed-by: shveta malik <shveta.malik@gmail.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Discussion: https://postgr.es/m/OS0PR01MB5716B44052000EB91EFAE60E94BC2@OS0PR01MB5716.jpnprd01.prod.outlook.com
Before commit a0ed19e0a9 there was a cast around these, but the cast
inadvertently changed the signedness, but that made the format
placeholder correct. Commit a0ed19e0a9 removed the casts, so now the
format placeholders had the wrong signedness.
Index vacuuming and [auto]prewarm AIO concurrency should be governed by
maintenance_io_concurrency. As such, pass those read stream users the
READ_STREAM_MAINTENANCE flag which will calculate their read stream
distance with maintenance_io_concurrency instead of
effective_io_concurrency. This was an oversight in the original commits
making those operations use the read stream API.
Discussion: https://postgr.es/m/flat/CAAKRu_aopDxTo4b41Mt_7Zc-z0_ngocrY8SFCCY6Aph1HgwuNw%40mail.gmail.com
Checking if another primitive scan is required after all once the next
leaf page was moved from _bt_checkkeys to its _bt_readpage caller by
commit 9a2e2a28. Update a comment that incorrectly described the
recheck mechanism as something that takes place in _bt_checkkeys.
Also fix an older typo in related code comments.
_bt_check_compare neglected to handle a case that can arise when the
scan's keys are temporarily treated as nonrequired, as an optimization:
whenever a NULL tuple value was encountered that had a skip array whose
current element wasn't already NULL, _bt_check_compare failed to advance
the array to the NULL element. This allowed _bt_check_compare to fail
to return matching tuples containing a NULL value (though only with an
array column that came before a skip array column with NULLs, and only
during _bt_readpage calls that set pstate.forcenonrequired=true on a
page where the higher-order column also had to advance).
To fix, teach _bt_check_compare to handle this case just like any other
case where a skip array key is unsatisfied and must be advanced directly
(due to the key being considered a nonrequired key).
Oversight in commit 8a510275, which optimized nbtree search scan key
comparisons with skip arrays.
Author: Peter Geoghegan <pg@bowt.ie>
Reported-By: Mark Dilger <mark.dilger@enterprisedb.com>
Discussion: https://postgr.es/m/CAHgHdKtLFWZcjr87hMH0hYDHgcifu4Tj7iHz-xh8qsJREt5cqA@mail.gmail.com
During logical decoding, we advance catalog_xmin of logical too early in
fast_forward mode, resulting in required catalog data being removed by
vacuum. This mode is normally used to advance the slot without processing
the changes, but we still can't let the slot's xmin to advance to an
incorrect value.
Commit f49a80c481 fixed a similar issue where the logical slot's
catalog_xmin was getting advanced prematurely during non-fast-forward
mode. During xl_running_xacts processing, instead of directly advancing
the slot's xmin to the oldest running xid in the record, it allowed the
xmin to be held back for snapshots that can be used for
not-yet-replayed transactions, as those might consider older txns as
running too. However, it missed the fact that the same problem can happen
during fast_forward mode decoding, as we won't build a base snapshot in
that mode, and the future call to get_changes from the same slot can miss
seeing the required catalog changes leading to incorrect reslts.
This commit allows building the base snapshot even in fast_forward mode to
prevent the early advancement of xmin.
Reported-by: Amit Kapila <amit.kapila16@gmail.com>
Author: Zhijie Hou <houzj.fnst@fujitsu.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: shveta malik <shveta.malik@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Backpatch-through: 13
Discussion: https://postgr.es/m/CAA4eK1LqWncUOqKijiafe+Ypt1gQAQRjctKLMY953J79xDBgAg@mail.gmail.com
Discussion: https://postgr.es/m/OS0PR01MB57163087F86621D44D9A72BF94BB2@OS0PR01MB5716.jpnprd01.prod.outlook.com
wait_event_types.h is generated by the code, and included wait_event.h.
wait_event.h did the opposite move, including wait_event_types.h,
causing a circular dependency between both.
wait_event_types.h only needs to now about the wait event classes, so
this information is moved into its own file, and wait_event_types.h uses
this new header so as it does not depend anymore on wait_event.h.
Note that such errors can be found with clang-tidy, with commands like
this one:
clang-tidy source_file.c --checks=misc-header-include-cycle -- \
-I/install/path/include/ -I/install/path/include/server/
Issue introduced by fa88928470.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://postgr.es/m/350192.1745768770@sss.pgh.pa.us
fc069a3a63 implements Self-Join Elimination (SJE), which can remove base
relations when appropriate. However, regressions tests for SJE only cover
the case when placeholder variables (PHVs) are evaluated and needed only
in a single base rel. If this baserel is removed due to SJE, its clauses,
including PHVs, will be transferred to the keeping relation. Removing these
PHVs may trigger an error on plan creation -- thanks to the b3ff6c742f for
detecting that.
This commit skips removal of PHVs during SJE. This might also happen that
we skip the removal of some PHVs that could be removed. However, the overhead
of extra PHVs is small compared to the complexity of analysis needed to remove
them.
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Author: Alena Rybakina <a.rybakina@postgrespro.ru>
Author: Andrei Lepikhov <lepihov@gmail.com>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
Reviewed-by: Richard Guo <guofenglinux@gmail.com>
Per our usual policy, Postgres header files should not include these;
the decision as to which one to use is to be made in the calling .c
file instead.
These errors aren't particularly new, but I'm not feeling a need
to back-patch these changes; it's mostly just neatnik-ism.
This cleans up some loose ends left by commit e8ca9ed1d. I hadn't
looked closely enough at these places before, but now I have.
The use of double-quoted #includes for Perl headers in plperl_system.h
seems to be simply a mistake introduced in 6c944bf3c and faithfully
copied forward since then. (I had thought possibly it was required
by some weird Windows build setup, but there's no evidence of that in
our history.)
The occurrences in SectionMemoryManager.h and SectionMemoryManager.cpp
evidently stem from those files' origin as LLVM code. It's
understandable that LLVM would treat their own files as needing
double-quoted #includes; but they're still system headers to us.
I also applied the same check to *.c files, and found a few other
random incorrect usages in both directions.
Our ECPG headers and test files routinely use angle brackets to refer
to ECPG headers. I left those usages alone, since it seems reasonable
for an ECPG user to regard those headers as system headers.
plpython.h included plpy_util.h, simply on the grounds that "it's
easier to just include it everywhere". However, plpy_util.h must
include plpython.h, or it won't pass headerscheck. While the
resulting circularity doesn't have any immediate bad effect,
it's poor design. We have seen serious messes arise in the past
from overly-broad inclusion footprints created by such circularities,
so let's establish a project policy against it.
To fix, just replace *.c files' inclusions of plpython.h with
plpy_util.h. They'll pull in plpython.h indirectly; indeed, almost
all have already done so via inclusions of other plpy_xxx.h headers.
(Any extensions using plpython.h can do likewise without breaking
the compatibility of their code with prior Postgres versions.)
Reported-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://postgr.es/m/aAxQ6fcY5QQV1lo3@ip-10-97-1-34.eu-west-3.compute.internal
While few if any C compilers will complain about this, it's
inconsistent with our other #include's of the same headers.
There are some other questionable usages in
src/include/jit/SectionMemoryManager.h and
src/pl/plperl/plperl_system.h, but perhaps those have a
reason to be like that. I can't see that these do.
Noticed while fooling around with a script to do analysis
of our header cross-inclusions.
c4d5cb71d2 adjusted the fast-path locking code to allow some
configuration of the number of fast-path locking slots via the
max_locks_per_transaction GUC. In that commit the FAST_PATH_REL_GROUP()
macro used integer division to determine the fast-path locking group slot
to use for the lock.
The divisor in this case is always a power-of-two value. Here we swap
out the divide by a bitwise-AND, which is a significantly faster
operation to perform.
In passing, adjust the code that's setting FastPathLockGroupsPerBackend
so that it's more clear that the value being set is a power-of-two.
Also, adjust some comments in the area which contained some magic
numbers. It seems better to justify the 1024 upper limit in the
location where the #define is made instead of where it is used.
Author: David Rowley <drowleyml@gmail.com>
Reviewed-by: Tomas Vondra <tomas@vondra.me>
Discussion: https://postgr.es/m/CAApHDvodr3bcnpxcs7+k-3cFwYR0tP-BYhyd2PpDhe-bCx9i=g@mail.gmail.com
10f6646847 intended to limit the value of io_combine_limit to the minimum of
io_combine_limit and io_max_combine_limit. To avoid issues with interdependent
GUCs, it introduced io_combine_limit_guc and set io_combine_limit in assign
hooks. That plan was thwarted by guc_tables.c accidentally still referencing
io_combine_limit, instead of io_combine_limit_guc. That lead to the GUC
machinery overriding the work done in the assign hooks, potentially leaving
io_combine_limit with a too high value.
The consequence of this bug was that when running with io_combine_limit >
io_combine_limit_guc the AIO machinery would not have reserved large enough
iovec and IO data arrays, with one IO's arrays overlapping with another IO's,
leading to total confusion.
To make such a problem easier to detect in the future, add assertions to
pgaio_io_set_handle_data_* checking the length is smaller than
io_max_combine_limit (not just PG_IOV_MAX).
It'd be nice to have a few tests for this, but it's not entirely obvious how
to do so portably.
As remarked upon by Tom, the GUC assignment hooks really shouldn't set the
underlying variable, that's the job of the GUC machinery. Change that as well.
Discussion: https://postgr.es/m/c5jyqnuwrpigd35qe7xdypxsisdjrdba5iw63mhcse4mzjogxo@qdjpv22z763f
pgaio_io_reclaim() reset the fields in PgAioHandle before updating the state
to IDLE or incrementing the generation. For most things that's OK, but for
pg_get_aios() it is not - if it copied the PgAioHandle while fields were being
reset, we wouldn't detect that and could call
pgaio_io_get_target_description() with ioh->target == PGAIO_TID_INVALID,
leading to a crash.
Fix this issue by incrementing the generation and state earlier, before
resetting.
Also add an assertion to pgaio_io_get_target_description() for the target to
be valid - that'd have made this case a bit easier to debug. While at it,
add/update a few related assertions.
Author: Alexander Lakhin <exclusion@gmail.com>
Discussion: https://postgr.es/m/062daca9-dfad-4750-9da8-b13388301ad9@gmail.com
Before commit a0ed19e0a9 there was a cast around these, but the cast
inadvertently changed the signedness, but that made the format
placeholder correct. Commit a0ed19e0a9 removed the casts, so now the
format placeholders had the wrong signedness.
A correct cocktail of COPY FROM, SELECT and/or DML queries and
\syncpipeline was able to break the logic in charge of discarding
results of a pipeline, done in discardAbortedPipelineResults(). Such
sequence make the backend generate a FATAL, due to a protocol
synchronization loss.
This problem comes down to the fact that we did not consider the case of
libpq returning a PGRES_FATAL_ERROR when discarding the results of an
aborted pipeline. The discarding code is changed so as this result
status is handled as a special case, with the caller of
discardAbortedPipelineResults() being responsible for consuming the
result.
A couple of tests are added to cover the problems reported, bringing an
interesting gain in coverage as there were no tests in the tree covering
the case of protocol synchronization loss.
Issue introduced by 41625ab8ea.
Reported-by: Alexander Kozhemyakin <a.kozhemyakin@postgrespro.ru>
Author: Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com>
Co-authored-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/ebf6ce77-b180-4d6b-8eab-71f641499ddf@postgrespro.ru
Not having this check would produce a core dump at startup when running
pgstat_read_statsfile(), in the case where the information of a stats
kind for an entry in the dshash could not be found. The same check
already happens for fixed-numbered stats and entries that are stored
with their names. This issue can be seen with custom stats kinds.
Note that this problem can be reproduced what what is in the core code:
- Tweak the test module injection_points to not load the fixed-numbered
stats part, leaving only the variable-numbered stats.
- Create an instance with injection_points defined in
shared_preload_libraries.
- Create a pgstats entry by attaching and running a point.
- Restart the server without shared_preload_libraries. The startup
process detects that something is wrong and reports a WARNING.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://postgr.es/m/aAieZAvM+K1d89R2@ip-10-97-1-34.eu-west-3.compute.internal
One place in hash_create() used DynaHashAlloc() as a convenient
shorthand for MemoryContextAlloc(). That was fine when it was
written, but it stopped being fine when 9c911ec06 changed
DynaHashAlloc() to use MCXT_ALLOC_NO_OOM (mea culpa). Change
the code to call plain MemoryContextAlloc() as intended.
I think that this bug may be unreachable in practice, since we now
always create AllocSets with some space already allocated, so that
an OOM failure here for a non-shared hash table should be impossible
(with a hash table name of reasonable length anyway). And there
aren't enough shared hash tables to make a crash for one of those
probable. Nonetheless it's clearly not operating as designed, so
back-patch to v16 where 9c911ec06 came in.
Reported-by: Maksim Korotkov <m.korotkov@postgrespro.ru>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/219bdccd460510efaccf90b57e5e5ef2@postgrespro.ru
Backpatch-through: 16
b85a9d046e introduced a new RelIdToTypeIdCacheHash, whose entries should
exist for typecache entries with TCFLAGS_HAVE_PG_TYPE_DATA flag set or any
of TCFLAGS_OPERATOR_FLAGS set or tupDesc set. However, TypeCacheOpcCallback(),
which resets TCFLAGS_OPERATOR_FLAGS, was forgotten to update
RelIdToTypeIdCacheHash.
This commit adds a delete_rel_type_cache_if_needed() call to the
TypeCacheOpcCallback() function to maintain RelIdToTypeIdCacheHash after
resetting TCFLAGS_OPERATOR_FLAGS.
Also, this commit fixes the name of the delete_rel_type_cache_if_needed()
function in its mentions in the comments.
Reported-by: Noah Misch
Discussion: https://postgr.es/m/20250411203241.e9.nmisch%40google.com
To estimate with extended statistics, we need to clear the varnullingrels
field in the expression, and duplicates are not allowed in the GroupVarInfo
list. We might re-use add_unique_group_var(), but we don't do so for two
reasons.
1) We must keep the origin_rinfos list ordered exactly the same way as
varinfos.
2) add_unique_group_var() is designed for estimate_num_groups(), where a
larger number of groups is worse. While estimating the number of hash
buckets, we have the opposite: a lesser number of groups is worse.
Therefore, we don't have to remove "known equal" vars: the removed var
may valuably contribute to the multivariate statistics to grow the number
of groups.
This commit adds custom code to estimate_multivariate_bucketsize() to
initialize varinfos properly.
Reported-by: Robins Tharakan <tharakan@gmail.com>
Discussion: https://postgr.es/m/18885-da51324078588253%40postgresql.org
Author: Andrei Lepikhov <lepihov@gmail.com>
Reviewed-by: David Rowley <dgrowleyml@gmail.com>
Reviewed-by: Tomas Vondra <tomas@vondra.me>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
When a foreign key constraint is placed on a partitioned table, we
actually make two pg_constraint entries associated with that table.
(I have my doubts about the wisdom of that, but it's been like that
since v12 and post-feature-freeze is no time to be messing with such
entrenched decisions.) The second "child" entry always had a name
generated according to the default rule, "table_column(s)_fkey[nnn]",
even if the primary entry had an unrelated user-specified name. The
trouble with doing that is that the default name could collide with
the user-specified name of some other constraint on the same table.
While we were willing to adjust the generated name to avoid
collisions, that only helps if it's made second; if it's made first
then creation of the other constraint would fail, potentially causing
dump/reload or pg_upgrade failures.
The core of the problem here is that we're infringing on user
namespace, so I doubt that there's any 100% solution other than to
find a way to not need the "child" entry. In the meantime, it seems
like it'd be an improvement to make the child's name be the name of
the parent constraint with an underscore and digit(s) appended as
necessary to make it unique. This rule can in theory fail in the same
way, but it seems much less probable; for one thing, this rule is
guaranteed not to match primary entries having auto-generated names.
(While an auto-generated primary name isn't user-specified to begin
with, it acts like that during dump/reload, so collisions against such
names are definitely possible.)
An additional bonus, visible in some of the regression test cases
that change here, arises from the fact that some error messages
cite the child constraint's name not the parent's. In the
previous approach the two names could be completely unrelated,
leading to user confusion --- the more so since psql's \d command
hides child constraints. With this approach it's hopefully much
clearer which constraint-the-user-knows-about is failing.
However, that does mean that there's user-visible behavior change
occurring here, making it seem like not something to back-patch.
I feel it's not too late for v18, though.
Reported-by: Kirill Reshke <reshkekirill@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Alvaro Herrera <alvherre@kurilemu.de>
Discussion: https://postgr.es/m/CALdSSPhGitjpTfzEMJN-Y2x+Q-5QChSxAsmSJ1-E8mQJLkHOqQ@mail.gmail.com
The stack allocated JsonLexContexts, in combination with codepaths
using goto, were causing warnings when compiling with LTO enabled
as the optimizer is unable to figure out that is safe. Rather than
contort the code with workarounds for this simply heap allocate the
structs instead as these are not in any performance critical paths.
Author: Daniel Gustafsson <daniel@yesql.se>
Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Jacob Champion <jacob.champion@enterprisedb.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/2074634.1744839761@sss.pgh.pa.us
The routine was coded so as a WAL sender was always used, state required
only for one failure test related to START_REPLICATION. This test is
changed so as a WAL sender is used by passing a replication option to
psql_fails_like(), instead of forcing the use of a WAL sender for all
the tests.
This has come up as useful in the context of a separate bug fix where
we are looking at extending tests for some failure scenarios. These
tests need to happen in the context of a normal backend, and not a WAL
sender where the extended query protocol cannot be used.
Discussion: https://postgr.es/m/aAXkJIOildLUA7vQ@paquier.xyz
Commit 3f28b2fcac tried to ensure that the replication origin shouldn't be
advanced in case of an ERROR in the apply worker, so that it can request
the same data again after restart. However, it is possible that an ERROR
was caught and handled by a (say PL/pgSQL) function, and the apply worker
continues to apply further changes, in which case, we shouldn't reset the
replication origin.
Ensure to reset the origin only when the apply worker exits after an
ERROR.
Commit 3f28b2fcac added new function geterrlevel, which we removed in HEAD
as part of this commit, but kept it in backbranches to avoid breaking any
applications. A separate case can be made to have such a function even for
HEAD.
Reported-by: Shawn McCoy <shawn.the.mccoy@gmail.com>
Author: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: vignesh C <vignesh21@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Backpatch-through: 16, where it was introduced
Discussion: https://postgr.es/m/CALsgZNCGARa2mcYNVTSj9uoPcJo-tPuWUGECReKpNgTpo31_Pw@mail.gmail.com
This assertion, based on pending_since (timestamp used to prevent stats
reports to be too frequent or should a partial flush happen), is reached
when it is found that no data can be flushed but a previous call of
pgstat_report_stat() determined that some stats data has been found as
in need of a flush. So pending_since is set when some stats data is
pending (in non-force mode) or if report attempts are too frequent, and
reset to 0 once all stats have been flushed.
Since 5cbbe70a9c, WAL senders have begun to report their stats on a
periodic basis for IO stats in v16~ and backend stats on HEAD, creating
some friction with the concurrent pgstat_report_stat() calls that can
happen in the context of a WAL sender (shutdown callback doing a final
report or backend-related code paths). This problem is the cause of
spurious failures in the TAP tests.
In theory, this assertion can be also reached in v15, even if that's
very unlikely. For example, a process, say a background worker, could
do periodic and direct stats flushes with concurrent calls of
pgstat_report_stat() that could cause conflicting values of
pending_since. This can be done with WAL or SLRU stats flushes using
pgstat_flush_wal() or pgstat_slru_flush(). HEAD makes this situation
easier to happen with custom cumulative stats.
This commit removes the assertion altogether, per discussion, as it is
more useful to keep the state of things as they are for the WAL sender.
The assertion could use a special state based on for example
am_walsender, but I doubt that this would be meaningful in the long run
based on the other arguments raised while discussing this issue.
Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Reported-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/1489124.1744685908@sss.pgh.pa.us
Discussion: https://postgr.es/m/dwrkeszz6czvtkxzr5mqlciy652zau5qqnm3cp5f3p2po74ppk@omg4g3cc6dgq
Backpatch-through: 15
Cluster.pm's connect_fails routine has long had the ability to
sniff the postmaster log file for expected messages after a
connection failure. However, that's always had a race condition:
on some platforms it's possible for psql to exit and the test
script to slurp up the postmaster log before the backend process
has been able to write out its final log messages. Back in
commit 55828a6b6 we disabled a bunch of tests after discovering
that, and the aim of this patch is to re-enable them.
(The sibling function connect_ok doesn't seem to have a similar
problem, mainly because the messages we look for come out during
the authentication handshake, so that if psql reports successful
connection they should certainly have been emitted already.)
The solution used here is borrowed from 002_connection_limits.pl's
connect_fails_wait routine: set the server's log_min_messages setting
to DEBUG2 so that the postmaster will log child-process exit, and then
wait till we see that log entry before checking for the messages we
are actually interested in.
If a TAP test uses connect_fails' log_like or log_unlike options, and
forgets to set log_min_messages, those connect_fails calls will now
hang until timeout. Fixing up the existing callers shows that we had
several other TAP tests that were in theory vulnerable to the same
problem. It's unclear whether the lack of failures is just luck, or
lack of buildfarm coverage, or perhaps there is some obscure timing
effect that only manifests in SSL connections. In any case, this
change should in principle make those other call sites more robust.
I'm not inclined to back-patch though, unless sometime we observe
an actual failure in one of them.
Reported-by: Andrew Dunstan <andrew@dunslane.net>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/984fca80-85a8-4c6f-a5cc-bb860950b435@dunslane.net
While heapam reproduces the insertion order of rows well, updates
can move rows to varying places depending on autovacuum activity.
In most regression tests we've guarded against getting variable
results due to that, but float4.sql and float8.sql had escaped
notice so far because they update tables that are too small for
autovacuum to pay attention to.
With increasing interest in non-heap table AMs, it seems worth
allowing for update behaviors that are not like heapam's. Hence,
add ORDER BY to stabilize the results in case the updates put
the rows in a different order. (We'll continue to assume that a
seqscan will reproduce original insertion order, though. Removing
that assumption would require vastly-more-invasive test changes.)
Author: Pavel Borisov <pashkin.elfe@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CALT9ZEExHAnBoBVQzQuWPMKUbapF5-FBO3fdeYG3s2tuWQz1NQ@mail.gmail.com
