When calculating distance in brin_minmax_multi_distance_inet(), the
netmask was applied incorrectly. This results in (seemingly) incorrect
ordering of values, triggering an assert.
For builds without asserts this is mostly harmless - we may merge other
ranges, possibly resulting in slightly less efficient index. But it's
still correct and the greedy algorithm doesn't guarantee optimality
anyway.
Backpatch to 14, where minmax-multi indexes were introduced.
Reported by Dmitry Dolgov, investigation and fix by me.
Reported-by: Dmitry Dolgov
Backpatch-through: 14
Discussion: https://postgr.es/m/17774-c6f3e36dd4471e67@postgresql.org
The Memoize executor node stores the cache key values along with the
tuple(s) which were found in the outer node which match each key value,
however, when the planner tried to estimate how many entries could be
stored in the cache, it didn't take into account that the cache key must
also be stored. In many cases, this won't make a large difference as the
key is likely small in comparison to the tuple(s) being stored, however,
it's not impossible to craft cases where the key could take more memory
than the tuple(s) stored for it.
Here we adjust the planner so it takes into account the estimated amount
of memory to store the cache key. Effectively, this change will reduce
the estimated cache hit ratio when it's thought that not all items will
fit in the cache, thus Memoize will become more expensive in such cases.
The executor already takes into account the memory consumed by the cache
key, so here we only need to adjust the planner.
Discussion: https://postgr.es/m/CAApHDvqGErGuyBfQvBQrTCHDbzLTqoiW=_G9sOzeFxWEc_7auA@mail.gmail.com
When probing the Memoize cache to check if the current cache key values
exist in the cache, we perform an evaluation of the expressions making up
the cache key before probing the hash table for those values. This
operation could leak memory as it is possible that the cache key is an
expression which requires allocation of memory, as was the case in bug
17844.
Here we fix this by correctly switching to the per tuple context before
evaluating the cache expressions so that the memory is freed next time the
per tuple context is reset.
Bug: 17844
Reported-by: Alexey Ermakov
Discussion: https://postgr.es/m/17844-d2f6f9e75a622bed@postgresql.org
Backpatch-through: 14, where Memoize was introduced
nodeRead() will have created a Node struct that's only allocated big
enough for the specific node type, so copying sizeof(union ValUnion)
can be copying too much. This provokes valgrind complaints, and with
very bad luck could perhaps result in SIGSEGV.
While at it, tidy up _equalA_Const to avoid duplicate checks of isnull.
Per report from Alexander Lakhin. This code is new as of a6bc33019,
so no need to back-patch.
Discussion: https://postgr.es/m/4995256b-cc65-170e-0b22-60ad2cd535f1@gmail.com
Add versions of timestamptz + interval, timestamptz - interval, and
generate_series(timestamptz, ...) in which a timezone can be specified
explicitly instead of defaulting to the TimeZone GUC setting.
The new functions for the first two are named date_add and
date_subtract. This might seem too generic, but we could use
overloading to add additional variants if that seems useful.
Along the way, improve the docs' pretty inadequate explanation
of how timestamptz +- interval works.
Przemysław Sztoch and Gurjeet Singh; cosmetic changes and most of
the docs work by me
Discussion: https://postgr.es/m/01a84551-48dd-1359-bf7e-f6b0203a6bd0@sztoch.pl
We already had five copies of essentially the same logic, and an
upcoming patch introduces yet another use-case. That's past my
threshold of pain, so introduce a common subroutine. There's not
that much net code savings, but the chance of typos should go down.
Inspired by a patch from Przemysław Sztoch, but different in detail.
Discussion: https://postgr.es/m/01a84551-48dd-1359-bf7e-f6b0203a6bd0@sztoch.pl
Check whether the datctype is C to determine whether t_isspace() and
related functions use isspace() or iswspace().
Previously, t_isspace() checked whether the database default collation
was C; which is incorrect when the default collation uses the ICU
provider.
Discussion: https://postgr.es/m/79e4354d9eccfdb00483146a6b9f6295202e7890.camel@j-davis.com
Reviewed-by: Peter Eisentraut
Backpatch-through: 15
Instead of trying to optimize this by skipping creation of the
links for tables we don't plan to dump, just create them all in
bulk with a single scan over the pg_inherits data. The previous
approach was more or less O(N^2) in the number of pg_inherits
entries, not to mention being way too complicated.
Also, don't create useless TableAttachInfo objects.
It's silly to create a TableAttachInfo object that we're not
going to dump, when we know perfectly well at creation time
that it won't be dumped.
Patch by me; thanks to Julien Rouhaud for review.
Discussion: https://postgr.es/m/1376149.1675268279@sss.pgh.pa.us
Hash partitioning on an enum is problematic because the hash codes are
derived from the OIDs assigned to the enum values, which will almost
certainly be different after a dump-and-reload than they were before.
This means that some rows probably end up in different partitions than
before, causing restore to fail because of partition constraint
violations. (pg_upgrade dodges this problem by using hacks to force
the enum values to keep the same OIDs, but that's not possible nor
desirable for pg_dump.)
Users can work around that by specifying --load-via-partition-root,
but since that's a dump-time not restore-time decision, one might
find out the need for it far too late. Instead, teach pg_dump to
apply that option automatically when dealing with a partitioned
table that has hash-on-enum partitioning.
Also deal with a pre-existing issue for --load-via-partition-root
mode: in a parallel restore, we try to TRUNCATE target tables just
before loading them, in order to enable some backend optimizations.
This is bad when using --load-via-partition-root because (a) we're
likely to suffer deadlocks from restore jobs trying to restore rows
into other partitions than they came from, and (b) if we miss getting
a deadlock we might still lose data due to a TRUNCATE removing rows
from some already-completed restore job.
The fix for this is conceptually simple: just don't TRUNCATE if we're
dealing with a --load-via-partition-root case. The tricky bit is for
pg_restore to identify those cases. In dumps using COPY commands we
can inspect each COPY command to see if it targets the nominal target
table or some ancestor. However, in dumps using INSERT commands it's
pretty impractical to examine the INSERTs in advance. To provide a
solution for that going forward, modify pg_dump to mark TABLE DATA
items that are using --load-via-partition-root with a comment.
(This change also responds to a complaint from Robert Haas that
the dump output for --load-via-partition-root is pretty confusing.)
pg_restore checks for the special comment as well as checking the
COPY command if present. This will fail to identify the combination
of --load-via-partition-root and --inserts in pre-existing dump files,
but that should be a pretty rare case in the field. If it does
happen you will probably get a deadlock failure that you can work
around by not using parallel restore, which is the same as before
this bug fix.
Having done this, there seems no remaining reason for the alarmism
in the pg_dump man page about combining --load-via-partition-root
with parallel restore, so remove that warning.
Patch by me; thanks to Julien Rouhaud for review. Back-patch to
v11 where hash partitioning was introduced.
Discussion: https://postgr.es/m/1376149.1675268279@sss.pgh.pa.us
Mainly move some detail from errmsg to errdetail, remove explicit
mention of superuser where appropriate, since that is implied in most
permission checks, and make messages more uniform.
Author: Nathan Bossart <nathandbossart@gmail.com>
Discussion: https://www.postgresql.org/message-id/20230316234701.GA903298@nathanxps13
Checking whether entry->conn is NULL after doing disconnect_pg_server()
for that entry is pointless, as that function ensures that it is NULL.
Thinko in commit 7fc1a81e4; this would be harmless, so patch HEAD only.
Reviewed-by: Richard Guo and Daniel Gustafsson
Discussion: https://postgr.es/m/CAPmGK169vQ83PQwQkoxO-AK2EeK1EsgsxixedM%2BBLWEAhZ_AqQ%40mail.gmail.com
Since commit 7627b91cd5, libpq has used FD_CLOEXEC so that sockets
wouldn't be leaked to subprograms. With enough bad luck, a
multi-threaded program might fork in between the socket() and fcntl()
calls. We can close that tiny gap by using SOCK_CLOEXEC instead of a
separate call. While here, we might as well do the same for
SOCK_NONBLOCK, to save another syscall.
These flags are expected to appear in the next revision of the POSIX
standard, specifically to address this problem. Our Unixoid targets
except macOS and AIX have had them for a long time, and macOS would
hopefully use guarded availability to roll them out, so it seems enough
to use a simple ifdef test for availability until we hear otherwise.
Windows doesn't have them, but has non-inheritable sockets by default.
Discussion: https://postgr.es/m/CA%2BhUKGKb6FsAdQWcRL35KJsftv%2B9zXqQbzwkfRf1i0J2e57%2BhQ%40mail.gmail.com
Unfortunately it turns out that the logfile-only option added in b9f8d1cbad
is only available in openldap starting in 2.6.
Luckily the option to control the log level (loglevel/-s) have been around for
much longer. As it turns out loglevel/-s only control what goes into syslog,
not what ends up in the file specified with 'logfile' and stderr.
While we currently are specifying 'logfile', nothing ends up in it, as the
option only controls debug messages, and we didn't set a debug level. The
debug level can only be configured on the commandline and also prevents
forking. That'd require larger changes, so this commit doesn't tackle that
issue.
Specify the syslog level when starting slapd using -s, as that allows to
prevent all syslog messages if one uses '0' instead of 'none', while loglevel
doesn't prevent the first message.
Discussion: https://postgr.es/m/20230311233708.3yjdbjkly2q4gq2j@awork3.anarazel.de
Backpatch: 11-
Currently, there are quite a few places in reorderbuffer.c that tries to
access top-transaction for a subtransaction. This makes the code to access
top-transaction consistent and easier to follow.
Author: Peter Smith
Reviewed-by: Vignesh C, Sawada Masahiko
Discussion: https://postgr.es/m/CAHut+PuCznOyTqBQwjRUu-ibG-=KHyCv-0FTcWQtZUdR88umfg@mail.gmail.com
The logic added in 9d9c02ccd to determine when a qual can be used as a
WindowClause run condition failed to correctly check for subqueries in the
qual. This was being done correctly for normal subquery qual pushdowns,
it's just that 9d9c02ccd failed to follow the lead on that.
This also fixes various other cases where transforming the qual into a
WindowClause run condition in the subquery should have been disallowed.
Bug: #17826
Reported-by: Anban Company
Discussion: https://postgr.es/m/17826-7d8750952f19a5f5@postgresql.org
Backpatch-through: 15, where 9d9c02ccd was introduced.
Until now the tests using slapd spammed syslog for every connection /
query. Use logfile-only to prevent syslog activity. Unfortunately that only
takes effect after logging the first message, but that's still much better
than the prior situation.
Discussion: https://postgr.es/m/20230311233708.3yjdbjkly2q4gq2j@awork3.anarazel.de
Backpatch: 11-
Support for SCM credential authentication has been removed in the
backend in 9.1, and libpq has kept some code to handle it for
compatibility.
Commit be4585b, that did the cleanup of the backend code, has done
so because the code was not really portable originally. And, as there
are likely little chances that this is used these days, this removes the
remaining code from libpq. An error will now be raised by libpq if
attempting to connect to a server that returns AUTH_REQ_SCM_CREDS,
instead.
References to SCM credential authentication are removed from the
protocol documentation. This removes some meson and configure checks.
Author: Michael Paquier
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/ZBLH8a4otfqgd6Kn@paquier.xyz
Further to commit 6a9229da, checking for NULL is now redundant. An "out
of memory" error would have been thrown already by palloc() and treated
as FATAL, so we can delete a few more lines.
Back-patch to all releases, like those other commits.
Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/4040668.1679013388%40sss.pgh.pa.us
create_append_path() would only apply get_baserel_parampathinfo
when the path is for a partitioned table, but it's also potentially
useful for paths for UNION ALL appendrels. Specifically, that
supports building a Memoize path atop this one.
While we're in the vicinity, delete some dead code in
create_merge_append_plan(): there's no need for it to support
parameterized MergeAppend paths, and it doesn't look like that
is going to change anytime soon. It'll be easy enough to undo
this when/if it becomes useful.
Richard Guo
Discussion: https://postgr.es/m/CAMbWs4_ABSu4PWG2rE1q10tJugEXHWgru3U8dAgkoFvgrb6aEA@mail.gmail.com
gcc 12+ has complaints like the following:
../../../../../pgsql/src/backend/utils/adt/network.c: In function 'inetnot':
../../../../../pgsql/src/backend/utils/adt/network.c:1893:34: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=]
1893 | pdst[nb] = ~pip[nb];
| ~~~~~~~~~^~~~~~~~~~
../../../../../pgsql/src/include/utils/inet.h:27:23: note: at offset -1 into destination object 'ipaddr' of size 16
27 | unsigned char ipaddr[16]; /* up to 128 bits of address */
| ^~~~~~
../../../../../pgsql/src/include/utils/inet.h:27:23: note: at offset -1 into destination object 'ipaddr' of size 16
This is due to a compiler bug:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104986
It has been a year since the bug has been reported without getting fixed. As
the warnings are verbose and use of gcc 12 is becoming more common, it seems
worth working around the bug. Particularly because a simple reformulation of
the loop condition fixes the issue and isn't any less readable.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Author: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/144536.1648326206@sss.pgh.pa.us
Backpatch: 11-
A comment was left behind claiming that we needed to use malloc() rather
than palloc() because the corresponding free would run in another
thread, but that's not true anymore. Remove that comment. And, with
the reason being gone, we might as well actually use palloc().
Back-patch to supported releases, like d41a178b.
Discussion: https://postgr.es/m/CA%2BhUKG%2BpdM9v3Jv4tc2BFx2jh_daY3uzUyAGBhtDkotEQDNPYw%40mail.gmail.com
Clarify that ATTACH/DETACH PARTITION can be used to perform partition
maintenance with less locking than straight CREATE TABLE/DROP TABLE.
This was already stated in some places, but not emphasized.
Back-patch to v14 where DETACH PARTITION CONCURRENTLY was added.
(We had lower lock levels for ATTACH PARTITION before that, but
this wording wouldn't apply.)
Justin Pryzby, reviewed by Robert Treat and Jakub Wartak;
a little further wordsmithing by me
Discussion: https://postgr.es/m/20220718143304.GC18011@telsasoft.com
DecodeDateTime and DecodeTimeOnly had support for date input in the
style "Y2023M03D16", which the comments claimed to be an "ISO" format.
However, so far as I can find there is no such format in ISO 8601;
they write units before numbers in intervals, but not in datetimes.
Furthermore, the lesser-known ISO 8601-2 spec actually defines an
incompatible format "2023Y03M16D". None of our documentation mentions
such a format either. So let's just drop it.
That leaves us with only two cases for a prefix unit specifier in
datetimes: Julian dates written as Jnnnn, and the "T" separator
defined by ISO 8601. Add checks to catch misuse of these specifiers,
that is consecutive specifiers or a dangling specifier at the end of
the string. We do not however disallow a specifier that is separated
from the field that it disambiguates (by noise words or unrelated
fields). That being the case, remove some overly-aggressive error
checks from the ISOTIME cases.
Joseph Koshakow, editorialized a bit by me; thanks also to
Peter Eisentraut for some standards-reading.
Discussion: https://postgr.es/m/CAAvxfHf2Q1gKLiHGnuPOiyf0ASvKUM4BnMfsXuwgtYEb_Gx0Zw@mail.gmail.com
.../src/common/file_utils.c: In function ‘pg_pwrite_zeros’:
.../src/common/file_utils.c:543:9: warning: ‘static’ is not at beginning of declaration [-Wold-style-declaration]
543 | const static PGAlignedBlock zbuffer = {{0}}; /* worth BLCKSZ */
The user receiving the message might not understand where the
server's "current directory" is. "Data directory" seems clearer.
(This would not be good for frontend code, but both of these
messages are only issued in the backend.)
Kyotaro Horiguchi
Discussion: https://postgr.es/m/20230316.111646.1564684434328830712.horikyota.ntt@gmail.com
In the .pc (pkg-config) files generated by the make and meson builds,
the Requires.private entries use different delimiters. The make build
uses spaces, the meson build uses commas. The pkg-config documentation
says that it should be comma-separated, but apparently about half the
.pc in the wild use just spaces. The pkg-config source code
acknowledges that both commas and spaces work.
This changes the make build to use commas, for consistency.
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://www.postgresql.org/message-id/flat/1fb52d61-0964-2d8e-87d9-e8be830e2b24%40enterprisedb.com
This structure included only PgStat_FunctionCounts, and removing it
facilitates some upcoming refactoring for pgstatfuncs.c to use more
macros rather that mostly-duplicated functions.
Author: Bertrand Drouvot
Reviewed-by: Nathan Bossart
Discussion: https://postgr.es/m/11d531fe-52fc-c6ea-7e8e-62f1b6ec626e@gmail.com
\dx was used on pg_walinspect to list its objects in 1.0 but the names
of the objects in this version do not have an order that is always
guaranteed depending on the collation used. Rather than append a
COLLATE clause in the query of \dx, this tweaks the regression test to
produce an output whose order is guaranteed.
Reported-by: Andres Freund
Author: Bharath Rupireddy
Discussion: https://postgr.es/m/20230314215440.gma7g4keswdnldj5@awork3.anarazel.de
A failure in parsing the interval value defined in the \watch command
was silently switched to 1s of interval between two queries, which can
be confusing. This commit improves the error handling, and a couple of
tests are added to check after:
- An incorrect value.
- An out-of-range value.
- A negative value.
A value of zero is able to work now, meaning that there is no interval
of time between two queries in a \watch loop. No backpatch is done, as
it could break existing applications.
Author: Andrey Borodin
Reviewed-by: Kyotaro Horiguchi, Nathan Bossart, Michael Paquier
Discussion: https://postgr.es/m/CAAhFRxiZ2-n_L1ErMm9AZjgmUK=qS6VHb+0SaMn8sqqbhF7How@mail.gmail.com
This adds the ability to pretty-print XML documents ... according to
libxml's somewhat idiosyncratic notions of what's pretty, anyway.
One notable divergence from a strict reading of the spec is that
libxml is willing to collapse empty nodes "<node></node>" to just
"<node/>", whereas SQL and the underlying XML spec say that this
option should only result in whitespace tweaks. Nonetheless,
it seems close enough to justify using the SQL-standard syntax.
Jim Jones, reviewed by Peter Smith and myself
Discussion: https://postgr.es/m/2f5df461-dad8-6d7d-4568-08e10608a69b@uni-muenster.de
The hook can be installed by a shared_preload library.
A similar mechanism could be used for radius paswords, for example, and
the type name auth_password_hook_typ has been shosen with that in mind.
John Naylor and Andrew Dunstan
Discussion: https://postgr.es/m/469b06ed-69de-ba59-c13a-91d2372e52a9@dunslane.net
preprocess_targetlist thought PHVs couldn't appear here.
It was mistaken, as per report from Önder Kalacı.
Surveying other pull_var_clause calls, I noted no similar errors,
but I did notice that qual_is_pushdown_safe's assertion about
!contain_window_function was pointless, because the following
pull_var_clause call would complain about them anyway. In HEAD
only, remove the redundant Assert and improve the commentary.
Discussion: https://postgr.es/m/CACawEhUuum-gC_2S3sXLTcsk7bUSPSHOD+g1ZpfKaDK-KKPPWA@mail.gmail.com
The previous coding based on select() had commentary about historical
portability concerns. Use POSIX nanosleep() instead.
This has independently been suggested a couple of times before, but
never managed to stick. Since recent and proposed work removes other
uses of select(), and associated code and comments relating to its
non-portable interaction with signals, it seems like a good time to tidy
up this case, too.
Also modernize the explanation of why WaitLatch() is a better way to
wait.
Reviewed-by: Nathan Bossart <nathandbossart@gmail.com>
Suggested-by: Paul Guo <paulguo@gmail.com>
Suggested-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAAKRu_b-q0hXCBUCAATh0Z4Zi6UkiC0k2DFgoD3nC-r3SkR3tg%40mail.gmail.com
Discussion: https://postgr.es/m/CABQrizfxpBLZT5mZeE0js5oCh1tqEWvcGF3vMRCv5P-RwUY5dQ@mail.gmail.com
Discussion: https://postgr.es/m/4902.1552349020@sss.pgh.pa.us
There are still some systems that use traditional tick-based sleep
timing, but many including Linux, FreeBSD and macOS started using high
resolution timer hardware more directly a decade or two ago. Update our
comment about that. Also highlight that Windows is like the older
Unixen in that respect.
Author: Nathan Bossart <nathandbossart@gmail.com>
Discussion: https://postgr.es/m/CA%2BhUKG%2BogAon8_V223Ldv6taPR2uKH3X_UJ_A7LJAf3-VRARPA%40mail.gmail.com
The current implementation of _pgfstat64() is ineffective in detecting a
terminal handle or an anonymous named pipe. This commit improves our
port of fstat() to detect more efficiently such cases by relying on
GetFileType(), and returning more correct data when the type found is
either a FILE_TYPE_PIPE (_S_IFIFO) or a FILE_TYPE_CHAR (_S_IFCHR).
This is part of a more global fix to address failures when feeding the
output generated by pg_dump to pg_restore through a pipe, for example,
but not all of it. We are also going to need to do something about
fseek() and ftello() which are not reliable on WIN32 for the same cases
where fstat() was incorrect. Fixing fstat() is independent of the rest,
though, which is why both fixes are handled separately, and this is the
first part of it.
Reported-by: Daniel Watzinger
Author: Daniel Watzinger, Juan José Santamaría Flecha
Discussion: https://postgr.es/m/b1448cd7-871e-20e3-8398-895e2d1d3bf9@gmail.com
Backpatch-through: 14
Using REPLICA IDENTITY FULL on the publisher can lead to a full table scan
per tuple change on the subscription when REPLICA IDENTITY or PK index is
not available. This makes REPLICA IDENTITY FULL impractical to use apart
from some small number of use cases.
This patch allows using indexes other than PRIMARY KEY or REPLICA
IDENTITY on the subscriber during apply of update/delete. The index that
can be used must be a btree index, not a partial index, and it must have
at least one column reference (i.e. cannot consist of only expressions).
We can uplift these restrictions in the future. There is no smart
mechanism to pick the index. If there is more than one index that
satisfies these requirements, we just pick the first one. We discussed
using some of the optimizer's low-level APIs for this but ruled it out
as that can be a maintenance burden in the long run.
This patch improves the performance in the vast majority of cases and the
improvement is proportional to the amount of data in the table. However,
there could be some regression in a small number of cases where the indexes
have a lot of duplicate and dead rows. It was discussed that those are
mostly impractical cases but we can provide a table or subscription level
option to disable this feature if required.
Author: Onder Kalaci, Amit Kapila
Reviewed-by: Peter Smith, Shi yu, Hou Zhijie, Vignesh C, Kuroda Hayato, Amit Kapila
Discussion: https://postgr.es/m/CACawEhVLqmAAyPXdHEPv1ssU2c=dqOniiGz7G73HfyS7+nGV4w@mail.gmail.com
Commit 4753ef37 changed vacuum_delay_point() to use the WaitLatch() API,
to fix the problem that vacuum could keep running for a very long time
after the postmaster died.
Unfortunately, that broke commit caf626b2's support for fractional
vacuum_cost_delay, which shipped in PostgreSQL 12. WaitLatch() works in
whole milliseconds.
For now, revert the change from commit 4753ef37, but add an explicit
check for postmaster death. That's an extra system call on systems
other than Linux and FreeBSD, but that overhead doesn't matter much
considering that we willingly went to sleep and woke up again. (In
later work, we might add higher resolution timeouts to the latch API so
that we could do this with our standard programming pattern, but that
wouldn't be back-patched.)
Back-patch to 14, where commit 4753ef37 arrived.
Reported-by: Melanie Plageman <melanieplageman@gmail.com>
Discussion: https://postgr.es/m/CAAKRu_b-q0hXCBUCAATh0Z4Zi6UkiC0k2DFgoD3nC-r3SkR3tg%40mail.gmail.com
Our waitpid() emulation didn't prevent a PID from being recycled by the
OS before the call to waitpid(). The postmaster could finish up
tracking more than one child process with the same PID, and confuse
them.
Fix, by moving the guts of pgwin32_deadchild_callback() into waitpid(),
so that resources are released synchronously. The process and PID
continue to exist until we close the process handle, which only happens
once we're ready to adjust our book-keeping of running children.
This seems to explain a couple of failures on CI. It had never been
reported before, despite the code being as old as the Windows port.
Perhaps Windows started recycling PIDs more rapidly, or perhaps timing
changes due to commit 7389aad6 made it more likely to break.
Thanks to Alexander Lakhin for analysis and Andres Freund for tracking
down the root cause.
Back-patch to all supported branches.
Reported-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20230208012852.bvkn2am4h4iqjogq%40awork3.anarazel.de
Tomas Vondra
Peter Eisentraut
David Rowley
Tom Lane
Michael Paquier
Jeff Davis
Etsuro Fujita
Thomas Munro
Andres Freund
Amit Kapila
Andrew Dunstan
Alvaro Herrera