Commit 5bf748b8, which enhanced nbtree ScalarArrayOp execution, made
parallel index scans work with the new design for arrays via explicit
scheduling of primitive index scans. A backend that successfully
scheduled the scan's next primitive index scan saved its backend local
array keys in shared memory. Any backend could pick up the scheduled
primitive scan within _bt_first. This scheme decouples scheduling a
primitive scan from starting the scan (by performing another descent of
the index via a _bt_search call from _bt_first) to make things robust.
The scheme had a deadlock hazard, at least when the leader process
participated in the scan. _bt_parallel_seize had a code path that made
backends that were not in an immediate position to start a scheduled
primitive index scan wait for some other backend to do so instead.
Under the right circumstances, the leader process could wait here
forever: the leader would wait for any other backend to start the
primitive scan, while every worker was busy waiting on the leader to
consume tuples from the scan's tuple queue.
To fix, don't wait for a scheduled primitive index scan to be started by
some other eligible backend from within _bt_parallel_seize (when the
calling backend isn't in a position to do so itself). Return false
instead, while recording that the scan has a scheduled primitive index
scan in backend local state. This leaves the backend in the same state
as the existing case where a backend schedules (or tries to schedule)
another primitive index scan from within _bt_advance_array_keys, before
calling _bt_parallel_seize. _bt_parallel_seize already handles that
case by returning false without waiting, and without unsetting the
backend local state. Leaving the backend in this state enables it to
start a previously scheduled primitive index scan once it gets back to
_bt_first.
Oversight in commit 5bf748b8, which enhanced nbtree ScalarArrayOp
execution.
Matthias van de Meent, with tweaks by me.
Author: Matthias van de Meent <boekewurm+postgres@gmail.com>
Reported-By: Tomas Vondra <tomas@vondra.me>
Reviewed-By: Peter Geoghegan <pg@bowt.ie>
Discussion: https://postgr.es/m/CAH2-WzmMGaPa32u9x_FvEbPTUkP5e95i=QxR8054nvCRydP-sw@mail.gmail.com
Backpatch: 17-, where nbtree SAOP execution was enhanced.
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.
Discussion: https://postgr.es/m/18617-1cee4d2ed1f4e7ae@postgresql.org
Discussion: https://gitlab.gnome.org/GNOME/libxml2/-/issues/799
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.
Back-patch to all supported branches.
Per report and patch from Wolfgang Walther.
Discussion: https://postgr.es/m/0a997455-5aba-4cf2-a354-d26d8bcbfae6@technowledgy.de
The current method of detecting perl build flags breaks if the path to
perl contains a space. This change makes two improvements. First,
instead of getting a list of ldflags and ccdlflags and then trying to
filter those out of the reported ldopts, we tell perl to suppress
reporting those in the first instance. Second, it tells perl to parse
those and output them, one per line. Thus any space on the option in a
file name, for example, is preserved.
Issue reported off-list by Muralikrishna Bandaru
Discussion: https://postgr.es/01117f88-f465-bf6c-9362-083bd72ca305@dunslane.net
Backpatch to release 16.
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.
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.
Pavel Borisov
Discussion: https://postgr.es/m/18616-acbb9e5caf41e964@postgresql.org
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
Commit 2c27346ed6 fixed the behavior of JSON_QUERY() when WITH
CONDITIONAL WRAPPER is used, but the documentation example wasn't
updated to reflect this change. This commit updates the example to
show the correct result.
Per off-list report from Andreas Ulbrich.
Backpatch-through: 17
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
Discussion of commit ed055d249 revealed that we don't actually
want jsonpath's .string() method to depend on DateStyle, nor
TimeZone either, because the non-"_tz" jsonpath functions are
supposed to be immutable. Potentially we could allow a TimeZone
dependency in the "_tz" variants, but it seems better to just
uniformly define this method as returning the same string that
jsonb text output would do. That's easier to implement too,
saving a couple dozen lines.
Patch by me, per complaint from Peter Eisentraut. Back-patch
to v17 where this feature came in (in 66ea94e8e). Also
back-patch ed055d249 to provide test cases.
Discussion: https://postgr.es/m/5e8879d0-a3c8-4be2-950f-d83aa2af953a@eisentraut.org
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.
Discussion: https://postgr.es/m/18608-48de0717508ee429@postgresql.org
When building a JSON object, the code builds a hash table of keys, to
allow checking if the keys are unique. The uniqueness check and adding
the new key happens in json_unique_check_key(), but this assumes the
pointer to the key remains valid.
Unfortunately, two places passed pointers to keys in a buffer, while
also appending more data (additional key/value pairs) to the buffer.
With enough data the buffer is resized by enlargeStringInfo(), which
calls repalloc(), invalidating the earlier key pointers.
Due to this the uniqueness check may fail with both false negatives and
false positives, producing JSON objects with duplicate keys or failing
to produce a perfectly valid JSON object.
This affects multiple functions that enforce uniqueness of keys, all
introduced in PG16 with the new SQL/JSON:
- json_object_agg_unique / jsonb_object_agg_unique
- json_object / jsonb_objectagg
Existing regression tests did not detect the issue, simply because the
initial buffer size is 1024 and the objects were small enough not to
require the repalloc.
With a sufficiently large object, AddressSanitizer reported the access
to invalid memory immediately. So would valgrind, of course.
Fixed by copying the key into the hash table memory context, and adding
regression tests with enough data to repalloc the buffer. Backpatch to
16, where the functions were introduced.
Reported by Alexander Lakhin. Investigation and initial fix by Junwang
Zhao, with various improvements and tests by me.
Reported-by: Alexander Lakhin
Author: Junwang Zhao, Tomas Vondra
Backpatch-through: 16
Discussion: https://postgr.es/m/18598-3279ed972a2347c7@postgresql.org
Discussion: https://postgr.es/m/CAEG8a3JjH0ReJF2_O7-8LuEbO69BxPhYeXs95_x7+H9AMWF1gw@mail.gmail.com
We must drop whitespace while parsing the input, else libxml2
will include "blank" nodes that interfere with the desired
indentation behavior. The end result is that we didn't indent
nodes separated by whitespace.
Also, it seems that libxml2 may add a trailing newline when working
in DOCUMENT mode. This is semantically insignificant, so strip it.
This is in the gray area between being a bug fix and a definition
change. However, the INDENT option is still pretty new (since v16),
so I think we can get away with changing this in stable branches.
Hence, back-patch to v16.
Jim Jones
Discussion: https://postgr.es/m/872865a8-548b-48e1-bfcd-4e38e672c1e4@uni-muenster.de
When the ON ERROR / ON EMPTY behavior is to return NULL, returning
NULL directly from ExecEvalJsonExprPath() suffices. Therefore, there's
no need to create separate steps to check the error/empty flag or
those to evaluate the the constant NULL expression. This speeds up
common cases because the default ON ERROR / ON EMPTY behavior for
JSON_QUERY() and JSON_VALUE() is to return NULL. However, these steps
are necessary if the RETURNING type is a domain, as constraints on the
domain may need to be checked.
Reported-by: Jian He <jian.universality@gmail.com>
Author: Jian He <jian.universality@gmail.com>
Author: Amit Langote <amitlangote09@gmail.com>
Discussion: https://postgr.es/m/CACJufxEo4sUjKCYtda0_qt9tazqqKPmF1cqhW9KBOUeJFqQd2g@mail.gmail.com
Backpatch-through: 17
As introduced by f9900df5f9, 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.
Oversight in f9900df5f9.
Author: Michail Nikolaev
Discussion: https://postgr.es/m/CANtu0oj9A3kZVduFTG0vrmGnKB+DCHgEpzOp0qAyOgmks84j0w@mail.gmail.com
Backpatch-through: 14
pg_stat_get_io() applied TimestampTzGetDatum twice to the
stat_reset_timestamp value. On 64-bit builds that's harmless because
TimestampTzGetDatum is a no-op, but on 32-bit builds it results in
displaying garbage in the stats_reset column of the pg_stat_io view.
Bug dates to commit a9c70b46d which introduced pg_stat_io, so
back-patch to v16 where that came in.
Bertrand Drouvot
Discussion: https://postgr.es/m/Ztrd+XcPTz1zorkg@ip-10-97-1-34.eu-west-3.compute.internal
The deparsing code in get_json_expr_options() unnecessarily emitted
the default column-specific ON ERROR / EMPTY behavior when the
top-level ON ERROR behavior in JSON_TABLE was set to ERROR. Fix that
by not overriding the column-specific default, determined based on
the column's JsonExprOp in get_json_table_columns(), with
JSON_BEHAVIOR_ERROR when that is the top-level ON ERROR behavior.
Note that this only removes redundancy; the current deparsing output
is not incorrect, just redundant.
Reviewed-by: Jian He <jian.universality@gmail.com>
Discussion: https://postgr.es/m/CACJufxEo4sUjKCYtda0_qt9tazqqKPmF1cqhW9KBOUeJFqQd2g@mail.gmail.com
Backpatch-through: 17
When the ON ERROR / ON EMPTY behavior is to return NULL, returning
NULL directly from ExecEvalJsonExprPath() suffices. Therefore, there's
no need to create separate steps to check the error/empty flag or
those to evaluate the the constant NULL expression. This speeds up
common cases because the default ON ERROR / ON EMPTY behavior for
JSON_QUERY() and JSON_VALUE() is to return NULL. However, these steps
are necessary if the RETURNING type is a domain, as constraints on the
domain may need to be checked.
Reported-by: Jian He <jian.universality@gmail.com>
Author: Jian He <jian.universality@gmail.com>
Author: Amit Langote <amitlangote09@gmail.com>
Discussion: https://postgr.es/m/CACJufxEo4sUjKCYtda0_qt9tazqqKPmF1cqhW9KBOUeJFqQd2g@mail.gmail.com
Backpatch-through: 17
The deparsing code in get_json_expr_options() unnecessarily emitted
the default column-specific ON ERROR / EMPTY behavior when the
top-level ON ERROR behavior in JSON_TABLE was set to ERROR. Fix that
by not overriding the column-specific default, determined based on
the column's JsonExprOp in get_json_table_columns(), with
JSON_BEHAVIOR_ERROR when that is the top-level ON ERROR behavior.
Note that this only removes redundancy; the current deparsing output
is not incorrect, just redundant.
Reviewed-by: Jian He <jian.universality@gmail.com>
Discussion: https://postgr.es/m/CACJufxEo4sUjKCYtda0_qt9tazqqKPmF1cqhW9KBOUeJFqQd2g@mail.gmail.com
Backpatch-through: 17
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.
Discussion: https://postgr.es/m/CACiT8iZ_diop=0zJ7zuY3BXegJpkKK1Av-PU7xh0EDYHsa5+=g@mail.gmail.com
This term was using an inconsistent casing between the code and the
documentation, using "CommitTsSLRU" in wait_event_names.txt and
"CommitTSSLRU" in the code.
Let's update the term in the code to reflect what's in the
documentation, "CommitTs" being more commonly used, so as
pg_stat_activity shows the same term as the documentation.
Oversight in 53c2a97a92.
Author: Alexander Lakhin
Discussion: https://postgr.es/m/f7e514cf-2446-21f1-a5d2-8c089a6e2168@gmail.com
Backpatch-through: 17
These tests depend on the test module injection_points to be installed,
but it may not be available as the contents of src/test/modules/ are not
installed by default.
This commit adds a workaround based on a scan of pg_available_extensions
to check if the extension is available, skipping the test if it is not.
This allows installcheck to work transparently.
There are more tests impacted by this problem on HEAD, but for now this
addresses only the tests that exist on HEAD and v17 as the release is
close by.
Reported-by: Maxim Orlov
Discussion: https://postgr.es/m/CACG=ezZkoT-pFz6a9XnyToiuR-Wg8fGELqHLoyBodr+2h-77qA@mail.gmail.com
Backpatch-through: 17
/usr/bin/msgfmt: po/fr.po: warning: PO file header fuzzy
warning: older versions of msgfmt will give an error on this
Apparently, not all versions of msgfmt produce this. Quick fix for
now, more to be researched later.
Commit b5a9b18c introduced block streaming infrastructure with a special
fast path for all-cached scans, and commit b7b0f3f2 connected the
infrastructure up to sequential scans. One of the fast path
micro-optimizations had an unintended consequence: it interfered with
parallel sequential scan's block range allocator (from commit 56788d21),
which has its own ramp-up and ramp-down algorithm when handing out
groups of pages to workers. A scan of an all-cached table could give
extra blocks to one worker, when others had finished. In some plans
(probably already very bad plans, such as the one reported by
Alexander), the unfairness could be magnified.
An internal buffer of 16 block numbers is removed, keeping just a single
block buffer for technical reasons.
Back-patch to 17.
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Discussion: https://postgr.es/m/63a63690-dd92-c809-0b47-af05459e95d1%40gmail.com
This change improves the description of the
restrict_nonsystem_relation_kind parameter in guc_table.c and the
documentation for better clarity.
Backpatch to 12, where this GUC parameter was introduced.
Reviewed-by: Peter Eisentraut
Discussion: https://postgr.es/m/6a96f1af-22b4-4a80-8161-1f26606b9ee2%40eisentraut.org
Backpatch-through: 12
This test occasionally shows
+WARNING: could not get result of cancel request due to timeout
which appears to be because the cancel request is sometimes unluckily
sent to the remote session between queries, and then it's ignored.
This patch tries to make that less probable in three ways:
1. Use a test query that does not involve remote estimates, so that
no EXPLAINs are sent.
2. Make sure that the remote session is ready-to-go (transaction
started, SET commands sent) before we start the timer.
3. Increase the statement_timeout to 100ms, to give the local
session enough time to plan and issue the query.
We might have to go higher than 100ms to make this adequately
stable in the buildfarm, but let's see how it goes.
Back-patch to v17 where this test was introduced.
Jelte Fennema-Nio and Tom Lane
Discussion: https://postgr.es/m/578934.1725045685@sss.pgh.pa.us
