818119afcc has introduced the "generation" concept in pgstats entries,
incremented a counter when a pgstats entry is reinitialized, but it did
not count on the fact that backends still holding local references to
such entries need to be refreshed if the cache age is outdated. The
previous logic only updated local references when an entry was dropped,
but it needs also to consider entries that are reinitialized.
This matters for replication slot stats (as well as custom pgstats kinds
in 18~), where concurrent drops and creates of a slot could cause
incorrect stats to be locally referenced. This would lead to an
assertion failure at shutdown when writing out the stats file, as the
backend holding an outdated local reference would not be able to drop
during its shutdown sequence the stats entry that should be dropped, as
the last process holding a reference to the stats entry. The
checkpointer was then complaining about such an entry late in the
shutdown sequence, after the shutdown checkpoint is finished with the
control file updated, causing the stats file to not be generated. In
non-assert builds, the entry would just be skipped with the stats file
written.
Note that only logical replication slots use statistics.
A test case based on TAP is added to test_decoding, where a persistent
connection peeking at a slot's data is kept with concurrent drops and
creates of the same slot. This is based on the isolation test case that
Anton has sent. As it requires a node shutdown with a check to make
sure that the stats file is written with this specific sequence of
events, TAP is used instead.
Reported-by: Anton A. Melnikov
Reviewed-by: Bertrand Drouvot
Discussion: https://postgr.es/m/56bf8ff9-dd8c-47b2-872a-748ede82af99@postgrespro.ru
Backpatch-through: 15
When short-circuiting WindowAgg node evaluation on the top-level
WindowAgg node using quals on monotonic window functions, because the
WindowAgg run condition can mean there's no need to evaluate subsequent
window function results in the same partition once the run condition
becomes false, it was possible that the executor would use stale results
from the previous invocation of the window function in some cases.
A fix for this was partially done by a5832722, but that commit only
fixed the issue for non-top-level WindowAgg nodes. I mistakenly thought
that the top-level WindowAgg didn't have this issue, but Jayesh's example
case clearly shows that's incorrect. At the time, I also thought that
this only affected 32-bit systems as all window functions which then
supported run conditions returned BIGINT, however, that's wrong as
ExecProject is still called and that could cause evaluation of any other
window function belonging to the same WindowAgg node, one of which may
return a byref type.
The only queries affected by this are WindowAggs with a "Run Condition"
which contains at least one window function with a byref result type,
such as lead() or lag() on a byref column. The window clause must also
contain a PARTITION BY clause (without a PARTITION BY, execution of the
WindowAgg stops immediately when the run condition becomes false and
there's no risk of using the stale results).
Reported-by: Jayesh Dehankar
Discussion: https://postgr.es/m/193261e2c4d.3dd3cd7c1842.871636075166132237@zohocorp.com
Backpatch-through: 15, where WindowAgg run conditions were added
Usually an entry in pg_amop or pg_amproc does not need a dependency on
its amoplefttype/amoprighttype/amproclefttype/amprocrighttype types,
because there is an indirect dependency via the argument types of its
referenced operator or procedure, or via the opclass it belongs to.
However, for some support procedures in some index AMs, the argument
types of the support procedure might not mention the column data type
at all. Also, the amop/amproc entry might be treated as "loose" in
the opfamily, in which case it lacks a dependency on any particular
opclass; or it might be a cross-type entry having a reference to a
datatype that is not its opclass' opcintype.
The upshot of all this is that there are cases where a datatype can
be dropped while leaving behind amop/amproc entries that mention it,
because there is no path in pg_depend showing that those entries
depend on that type. Such entries are harmless in normal activity,
because they won't get used, but they cause problems for maintenance
actions such as dropping the operator family. They also cause pg_dump
to produce bogus output. The previous commit put a band-aid on the
DROP OPERATOR FAMILY failure, but a real fix is needed.
To fix, add pg_depend entries showing that a pg_amop/pg_amproc entry
depends on its lefttype/righttype. To avoid bloating pg_depend too
much, skip this if the referenced operator or function has that type
as an input type. (I did not bother with considering the possible
indirect dependency via the opclass' opcintype; at least in the
reported case, that wouldn't help anyway.)
Probably, the reason this has escaped notice for so long is that
add-on datatypes and relevant opclasses/opfamilies are usually
packaged as extensions nowadays, so that there's no way to drop
a type without dropping the referencing opclasses/opfamilies too.
Still, in the absence of pg_depend entries there's nothing that
constrains DROP EXTENSION to drop the opfamily entries before the
datatype, so it seems possible for a DROP failure to occur anyway.
The specific case that was reported doesn't fail in v13, because
v13 prefers to attach the support procedure to the opclass not the
opfamily. But it's surely possible to construct other edge cases
that do fail in v13, so patch that too.
Per report from Yoran Heling. Back-patch to all supported branches.
Discussion: https://postgr.es/m/Z1MVCOh1hprjK5Sf@gmai021
Yoran Heling reported a case where a data type could be dropped
while references to its OID remain behind in pg_amproc. This
causes getObjectDescription to fail, which blocks dropping the
operator family (since our DROP code likes to construct descriptions
of everything it's dropping). The proper fix for this requires
adding more pg_depend entries. But to allow DROP to go through with
already-corrupt catalogs, tweak getObjectDescription to print "???"
for the type instead of failing when it processes such an entry.
I changed the logic for pg_amop similarly, for consistency,
although it is not known that the problem can manifest in pg_amop.
Per report from Yoran Heling. Back-patch to all supported
branches (although the problem may be unreachable in v13).
Discussion: https://postgr.es/m/Z1MVCOh1hprjK5Sf@gmai021
These format codes produce or consume strings of digits, so they
should be labeled with is_digit = true, but they were not.
This has effect in only one place, where is_next_separator()
is checked to see if the preceding format code should slurp up
all the available digits. Thus, with a format such as '...SSFF3'
with remaining input '12345', the 'SS' code would consume all
five digits (and then complain about seconds being out of range)
when it should eat only two digits.
Per report from Nick Davies. This bug goes back to d589f9446
where the FFn codes were introduced, so back-patch to v13.
Discussion: https://postgr.es/m/AM8PR08MB6356AC979252CFEA78B56678B6312@AM8PR08MB6356.eurprd08.prod.outlook.com
parallel_vacuum_reset_dead_items used a local variable to hold a
pointer from the passed vacrel, purely as a shorthand. This pointer
was later freed and a new allocation was made and stored to the
struct. Then the local pointer was mistakenly referenced again.
This apparently happened not to break anything since the freed chunk
would have been put on the context's freelist, so it was accidentally
the same pointer anyway, in which case the DSA handle was correctly
updated. The minimal fix is to change two places so they access
dead_items through the vacrel. This coding style is a maintenance
hazard, so while at it get rid of most other similar usages, which
were inconsistently used anyway.
Analysis and patch by Vallimaharajan G, with further defensive coding
by me
Backpath to v17, when TidStore came in
Discussion: https://postgr.es/m/1936493cc38.68cb2ef27266.7456585136086197135@zohocorp.com
The validate_sync_standby_slots subroutine requires an LWLock, so it
cannot run in processes without PGPROC; skip it there to avoid a crash.
This replaces the current test for ReplicationSlotCtl being not null,
which appears to be a solution for the same problem but less general.
I also rewrote a related comment that mentioned ReplicationSlotCtl in
StandbySlotsHaveCaughtup.
This code came in with commit bf279ddd1c28; backpatch to 17.
Reported-by: Gabriele Bartolini <gabriele.bartolini@enterprisedb.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Zhijie Hou <houzj.fnst@fujitsu.com>
Discussion: https://postgr.es/m/202411281216.sutbxtr6idnn@alvherre.pgsql
The last section of pg_createsubscriber used the terms
"publication-name", "replication-slot-name", and "subscription-name".
These terms are not defined on the page, which was confusing, and the
intention is clearly to refer to the values one would give to the
options --publication, --subscription and --replication-slot. Let's
simplify the documentation by mentioning the option switches, instead of
these terms.
Reported-by: Christophe Courtois
Author: Shubham Khanna
Reviewed-by: Vignesh C, Peter Smith
Discussion: https://postgr.es/m/173288198026.714.15127074046508836738@wrigleys.postgresql.org
Backpatch-through: 17
Previously, it set only DELAY_CHKPT_COMPLETE. That was important,
because it meant that if the XLOG_SMGR_TRUNCATE record preceded a
XLOG_CHECKPOINT_ONLINE record in the WAL, then the truncation would also
happen on disk before the XLOG_CHECKPOINT_ONLINE record was
written.
However, it didn't guarantee that the sync request for the truncation
was processed before the XLOG_CHECKPOINT_ONLINE record was written. By
setting DELAY_CHKPT_START, we guarantee that if an XLOG_SMGR_TRUNCATE
record is written to WAL before the redo pointer of a concurrent
checkpoint, the sync request queued by that operation must be processed
by that checkpoint, rather than being left for the following one.
This is a refinement of commit 412ad7a556. Back-patch to all supported
releases, like that commit.
Author: Robert Haas <robertmhaas@gmail.com>
Reported-by: Thomas Munro <thomas.munro@gmail.com>
Discussion: https://postgr.es/m/CA%2BhUKG%2B-2rjGZC2kwqr2NMLBcEBp4uf59QT1advbWYF_uc%2B0Aw%40mail.gmail.com
The loops over cursor argument variables neglected to ever advance
"prevvar". The code would accidentally do the right thing anyway
when removing the first or second list entry, but if it had to
remove the third or later entry then it would also remove all
entries between there and the first entry. AFAICS this would
only matter for cursors that reference out-of-scope variables,
which is a weird Informix compatibility hack; between that and
the lack of impact for short lists, it's not so surprising that
nobody has complained. Nonetheless it's a pretty obvious bug.
It would have been more obvious if these loops used a more standard
coding style for chasing the linked lists --- this business with the
"prev" pointer sometimes pointing at the current list entry is
confusing and overcomplicated. So rather than just add a minimal
band-aid, I chose to rewrite the loops in the same style we use
elsewhere, where the "prev" pointer is NULL until we are dealing with
a non-first entry and we save the "next" pointer at the top of the
loop. (Two of the four loops touched here are not actually buggy,
but it seems better to make them all look alike.)
Coverity discovered this problem, but not until 2b41de4a5 added code
to free no-longer-needed arguments structs. With that, the incorrect
link updates are possibly touching freed memory, and it complained
about that. Nonetheless the list corruption hazard is ancient, so
back-patch to all supported branches.
As I'd feared, commit 5c9d8636d was still a few bricks shy of a load.
We can't just leave pulled-up lateral-reference Vars with no new
nullingrels: we have to carefully compute what subset of the
to-be-replaced Var's nullingrels apply to them, else we still get
"wrong varnullingrels" errors. This is a bit tedious, but it looks
like we can use the nullingrel data this patch computes for other
purposes, enabling better optimization. We don't want to inject
unnecessary plan changes into stable branches though, so leave that
idea for a later HEAD-only patch.
Patch by me, but thanks to Richard Guo for devising a test case that
broke 5c9d8636d, and for preliminary investigation about how to fix
it. As before, back-patch to v16.
Discussion: https://postgr.es/m/E1tGn4j-0003zi-MP@gemulon.postgresql.org
If we are pulling up a subquery that's under an outer join, and
the subquery's target list contains a strict expression that uses
both a subquery variable and a lateral-reference variable, it's okay
to pull up the expression without wrapping it in a PlaceHolderVar.
That's safe because if the subquery variable is forced to NULL
by the outer join, the expression result will come out as NULL too,
so we don't have to force that outcome by evaluating the expression
below the outer join. It'd be correct to wrap in a PHV, but that can
lead to very significantly worse plans, since we'd then have to use
a nestloop plan to pass down the lateral reference to where the
expression will be evaluated.
However, when we do that, we should not mark the lateral reference
variable as being nulled by the outer join, because it isn't after
we pull up the expression in this way. So the marking logic added
by cb8e50a4a was incorrect in this detail, leading to "wrong
varnullingrels" errors from the consistency-checking logic in
setrefs.c. It seems to be sufficient to just not mark lateral
references at all in this case. (I have a nagging feeling that more
complexity may be needed in cases where there are several levels of
outer join, but some attempts to break it with that didn't succeed.)
Per report from Bertrand Mamasam. Back-patch to v16, as the previous
patch was.
Discussion: https://postgr.es/m/CACZ67_UA_EVrqiFXJu9XK50baEpH=ofEPJswa2kFxg6xuSw-ww@mail.gmail.com
1. The error reporting of "port setrequested list-of-packages..."
changed, hiding errors we were relying on to know if all packages in our
list were already installed. Use a loop instead.
2. The cached MacPorts installation was shared between PostgreSQL
major branches, though each branch wanted different packages. Add the
list of packages to cache key, so that different branches, when tested
in one github account/repo such as postgres/postgres, stop fighting with
each other, adding and removing packages.
Back-patch to 15 where CI began.
Author: Thomas Munro <thomas.munro@gmail.com>
Author: Nazir Bilal Yavuz <byavuz81@gmail.com>
Suggested-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/au2uqfuy2nf43nwy2txmc5t2emhwij7kzupygto3d2ffgtrdgr%40ckvrlwyflnh2
During pgbench's table initialization, progress updates could display
leftover characters from the previous message if the new message
was shorter. This commit resolves the issue by appending spaces to
the current message to fully overwrite any remaining characters from
the previous line.
Back-patch to all the supported versions.
Author: Yushi Ogiwara, Tatsuo Ishii, Fujii Masao
Reviewed-by: Tatsuo Ishii, Fujii Masao
Discussion: https://postgr.es/m/9a9b8b95b6a709877ae48ad5b0c59bb9@oss.nttdata.com
We added pg_constraint rows for all not-null constraints, first for
tables and later for domains; but while the ones for tables were
reverted, the ones for domains were not. However, we did accidentally
revert ruleutils.c support for the ones on domains in 6f8bb7c1e9,
which breaks running pg_get_constraintdef() on them. Put that back.
This is only needed in branch 17, because we've reinstated this code in
branch master with commit 14e87ffa5c. Add some new tests in both
branches.
I couldn't find anything else that needs de-reverting.
Reported-by: Erki Eessaar <erki.eessaar@taltech.ee>
Reviewed-by: Magnus Hagander <magnus@hagander.net>
Discussion: https://postgr.es/m/AS8PR01MB75110350415AAB8BBABBA1ECFE222@AS8PR01MB7511.eurprd01.prod.exchangelabs.com
Commit 9044fc1d45 added some files from upstream LLVM. These files
have different whitespace rules, which make the git whitespace checks
powered by gitattributes fail. To fix, add those files to the exclude
list.
When using a pipeline, a transaction starts from the first command and
is committed with a Sync message or when the pipeline ends.
Functions like IsInTransactionBlock() or PreventInTransactionBlock()
were already able to understand a pipeline as being in a transaction
block, but it was not the case of CheckTransactionBlock(). This
function is called for example to generate a WARNING for SET LOCAL,
complaining that it is used outside of a transaction block.
The current state of the code caused multiple problems, like:
- SET LOCAL executed at any stage of a pipeline issued a WARNING, even
if the command was at least second in line where the pipeline is in a
transaction state.
- LOCK TABLE failed when invoked at any step of a pipeline, even if it
should be able to work within a transaction block.
The pipeline protocol assumes that the first command of a pipeline is
not part of a transaction block, and that any follow-up commands is
considered as within a transaction block.
This commit changes the backend so as an implicit transaction block is
started each time the first Execute message of a pipeline has finished
processing, with this implicit transaction block ended once a sync is
processed. The checks based on XACT_FLAGS_PIPELINING in the routines
checking if we are in a transaction block are not necessary: it is
enough to rely on the existing ones.
Some tests are added to pgbench, that can be backpatched down to v17
when \syncpipeline is involved and down to v14 where \startpipeline and
\endpipeline are available. This is unfortunately limited regarding the
error patterns that can be checked, but it provides coverage for various
pipeline combinations to check if these succeed or fail. These tests
are able to capture the case of SET LOCAL's WARNING. The author has
proposed a different feature to improve the coverage by adding similar
meta-commands to psql where error messages could be checked, something
more useful for the cases where commands cannot be used in transaction
blocks, like REINDEX CONCURRENTLY or VACUUM. This is considered as
future work for v18~.
Author: Anthonin Bonnefoy
Reviewed-by: Jelte Fennema-Nio, Michael Paquier
Discussion: https://postgr.es/m/CAO6_XqrWO8uNBQrSu5r6jh+vTGi5Oiyk4y8yXDORdE2jbzw8xw@mail.gmail.com
Backpatch-through: 13
Most came in during the 17 cycle, so backpatch there. Some
(particularly reorderbuffer.h) are very old, but backpatching doesn't
seem useful.
Like commits c9d2977519, c4f113e8fe.
The approach of declaring a function pointer with an empty argument
list and hoping that the compiler will not complain about casting it
to another type no longer works with C23, because foo() is now
equivalent to foo(void).
We don't need to do this here. With a few struct forward declarations
we can supply a correct argument list without having to pull in
another header file.
(This is the only new warning with C23. Together with the previous
fix a67a49648d, this makes the whole code compile cleanly under C23.)
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/95c6a9bf-d306-43d8-b880-664ef08f2944%40eisentraut.org
Discussion: https://www.postgresql.org/message-id/flat/87o72eo9iu.fsf%40gentoo.org
If passed a read-write expanded object pointer, the EEOP_NULLIF
code would hand that same pointer to the equality function
and then (unless equality was reported) also return the same
pointer as its value. This is no good, because a function that
receives a read-write expanded object pointer is fully entitled
to scribble on or even delete the object, thus corrupting the
NULLIF output. (This problem is likely unobservable with the
equality functions provided in core Postgres, but it's easy to
demonstrate with one coded in plpgsql.)
To fix, make sure the pointer passed to the equality function
is read-only. We can still return the original read-write
pointer as the NULLIF result, allowing optimization of later
operations.
Per bug #18722 from Alexander Lakhin. This has been wrong
since we invented expanded objects, so back-patch to all
supported branches.
Discussion: https://postgr.es/m/18722-fd9e645448cc78b4@postgresql.org
This WARNING appeared because SearchSysCacheLocked1() read
cc_relisshared before catcache initialization, when the field is false
unconditionally. On the basis of reading false there, it constructed a
locktag as though pg_tablespace weren't relisshared. Only shared
catalogs could be affected, and only GRANT TABLESPACE was affected in
practice. SearchSysCacheLocked1() callers use one other shared-relation
syscache, DATABASEOID. DATABASEOID is initialized by the end of
CheckMyDatabase(), making the problem unreachable for pg_database.
Back-patch to v13 (all supported versions). This has no known impact
before v16, where ExecGrant_common() first appeared. Earlier branches
avoid trouble by having a separate ExecGrant_Tablespace() that doesn't
use LOCKTAG_TUPLE. However, leaving this unfixed in v15 could ensnare a
future back-patch of a SearchSysCacheLocked1() call.
Reported by Aya Iwata.
Discussion: https://postgr.es/m/OS7PR01MB11964507B5548245A7EE54E70EA212@OS7PR01MB11964.jpnprd01.prod.outlook.com
Commit bc5a4dfc accidentally left a check for <stdbool.h> in
meson.build's header_checks. Synchronize with configure, which no
longer defines HAVE_STDBOOL_H.
There is still a reference to <stdbool.h> in an earlier test to see if
we need -std=c99 to get C99 features, like autoconf 2.69's
AC_PROG_CC_C99. (Therefore the test remove by this commit was
tautological since day one: you'd have copped "C compiler does not
support C99" before making it this far.)
Back-patch to 16, where meson begins.
On ARM platforms where the baseline CPU target lacks CRC instructions,
we need to supply a -march flag to persuade the compiler to compile
such instructions. It turns out that our existing choice of
"-march=armv8-a+crc" has not worked for some time, because recent gcc
will interpret that as selecting software floating point, and then
will spit up if the platform requires hard-float ABI, as most do
nowadays. The end result was to silently fall back to software CRC,
which isn't very desirable since in practice almost all currently
produced ARM chips do have hardware CRC.
We can fix this by using "-march=armv8-a+crc+simd" to enable the
correct ABI choice. (This has no impact on the code actually
generated, since neither of the files we compile with this flag
does any floating-point stuff, let alone SIMD.) Keep the test for
"-march=armv8-a+crc" since that's required for soft-float ABI,
but try that second since most platforms we're likely to build on
use hard-float.
Since this isn't working as-intended on the last several years'
worth of gcc releases, back-patch to all supported branches.
Discussion: https://postgr.es/m/4496616.iHFcN1HehY@portable-bastien
Tcl 9 changed several API functions to take Tcl_Size, which is
ptrdiff_t, instead of int, for 64-bit enablement. We have to change a
few local variables to be compatible with that. We also provide a
fallback typedef of Tcl_Size for older Tcl versions.
The affected variables are used for quantities that will not approach
values beyond the range of int, so this doesn't change any
functionality.
Reviewed-by: Tristan Partin <tristan@partin.io>
Discussion: https://www.postgresql.org/message-id/flat/bce0fe54-75b4-438e-b42b-8e84bc7c0e9c%40eisentraut.org
Previously we checked "for <stdbool.h> that conforms to C99" using
autoconf's AC_HEADER_STDBOOL macro. We've required C99 since PostgreSQL
12, so the test was redundant, and under C23 it was broken: autoconf
2.69's implementation doesn't understand C23's new empty header (the
macros it's looking for went away, replaced by language keywords).
Later autoconf versions fixed that, but let's just remove the
anachronistic test.
HAVE_STDBOOL_H and HAVE__BOOL will no longer be defined, but they
weren't directly tested in core or likely extensions (except in 11, see
below). PG_USE_STDBOOL (or USE_STDBOOL in 11 and 12) is still defined
when sizeof(bool) is 1, which should be true on all modern systems.
Otherwise we define our own bool type and values of size 1, which would
fail to compile under C23 as revealed by the broken test. (We'll
probably clean that dead code up in master, but here we want a minimal
back-patchable change.)
This came to our attention when GCC 15 recently started using using C23
by default and failed to compile the replacement code, as reported by
Sam James and build farm animal alligator.
Back-patch to all supported releases, and then two older versions that
also know about <stdbool.h>, per the recently-out-of-support policy[1].
12 requires C99 so it's much like the supported releases, but 11 only
assumes C89 so it now uses AC_CHECK_HEADERS instead of the overly picky
AC_HEADER_STDBOOL. (I could find no discussion of which historical
systems had <stdbool.h> but failed the conformance test; if they ever
existed, they surely aren't relevant to that policy's goals.)
[1] https://wiki.postgresql.org/wiki/Committing_checklist#Policies
Reported-by: Sam James <sam@gentoo.org>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org> (master version)
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> (approach)
Discussion: https://www.postgresql.org/message-id/flat/87o72eo9iu.fsf%40gentoo.org
Per PEP 3114, iterator.next() has been renamed to iterator.__next__(),
and one example in the documentation still used next(). This caused the
example provided to fail the function creation since Python 2 is not
supported anymore since 19252e8ec9.
Author: Erik Wienhold
Discussion: https://postgr.es/m/173209043143.2092749.13692266486972491694@wrigleys.postgresql.org
Backpatch-through: 15
Commit d39a49c1e4 added new fields to the struct, but missed the "keep
these last" comment on the previous fields. Add placeholder variables
so that the offsets of the fields are the same whether you build with
USE_OPENSSL or not. This is a courtesy to extensions that might peek
at the fields, to make the ABI the same regardless of the options used
to build PostgreSQL.
In reality, I don't expect any extensions to look at the 'raw_buf'
fields. Firstly, they are new in v17, so no one's written such
extensions yet. Secondly, extensions should have no business poking at
those fields anyway. Nevertheless, fix this properly on 'master'. On
v17, we mustn't change the memory layout, so just fix the comments.
Author: Jacob Champion
Discussion: https://www.postgresql.org/message-id/raw/CAOYmi%2BmKVJNzn5_TD_MK%3DhqO64r_w8Gb0FHCLk0oAkW-PJv8jQ@mail.gmail.com
If a user started a bulk write operation on a fork with existing data
to append data in bulk, the bulk_write machinery would zero out all
previously written pages up to the last page written by the new
bulk_write operation.
This is not an issue for PostgreSQL itself, because we never use the
bulk_write facility on a non-empty fork. But there are use cases where
it makes sense. TimescaleDB extension is known to do that to merge
partitions, for example.
Backpatch to v17, where the bulk_write machinery was introduced.
Author: Matthias van de Meent <boekewurm+postgres@gmail.com>
Reported-By: Erik Nordström <erik@timescale.com>
Reviewed-by: Erik Nordström <erik@timescale.com>
Discussion: https://www.postgresql.org/message-id/CACAa4VJ%2BQY4pY7M0ECq29uGkrOygikYtao1UG9yCDFosxaps9g@mail.gmail.com
If the executable's .o files were produced by a compiler (probably gcc)
not using -moutline-atomics, and the corresponding .bc files were
produced by clang using -moutline-atomics (probably by default), then
the generated bitcode functions would have the target attribute
"+outline-atomics", and could fail at runtime when inlined. If the
target ISA at bitcode generation time was armv8-a (the most conservative
aarch64 target, no LSE), then LLVM IR atomic instructions would generate
calls to functions in libgcc.a or libclang_rt.*.a that switch between
LL/SC and faster LSE instructions depending on a runtime AT_HWCAP check.
Since the corresponding .o files didn't need those functions, they
wouldn't have been included in the executable, and resolution would
fail.
At least Debian and Ubuntu are known to ship gcc and clang compilers
that target armv8-a but differ on the use of outline atomics by default.
Fix, by suppressing the outline atomics attribute in bitcode explicitly.
Inline LL/SC instructions will be generated for atomic operations in
bitcode built for armv8-a. Only configure scripts are adjusted for now,
because the meson build system doesn't generate bitcode yet.
This doesn't seem to be a new phenomenon, so real cases of functions
using atomics that are inlined by JIT must be rare in the wild given how
long it took for a bug report to arrive. The reported case could be
reduced to:
postgres=# set jit_inline_above_cost = 0;
SET
postgres=# set jit_above_cost = 0;
SET
postgres=# select pg_last_wal_receive_lsn();
WARNING: failed to resolve name __aarch64_swp4_acq_rel
FATAL: fatal llvm error: Program used external function
'__aarch64_swp4_acq_rel' which could not be resolved!
The change doesn't affect non-ARM systems or later target ISAs.
Back-patch to all supported releases.
Reported-by: Alexander Kozhemyakin <a.kozhemyakin@postgrespro.ru>
Discussion: https://postgr.es/m/18610-37bf303f904fede3%40postgresql.org
It failed to set the archive_command as it desired because of a syntax
problem. Oversight in commit 90bcc7c2db.
This bug doesn't cause the test to fail, because the test only checks
pg_rewind's output messages, not the actual outcome (and the outcome in
both cases is that the file is kept, not deleted). But in either case
the message about the file being kept is there, so it's hard to get
excited about doing much more.
Reported-by: Antonin Houska <ah@cybertec.at>
Author: Alexander Kukushkin <cyberdemn@gmail.com>
Discussion: https://postgr.es/m/7822.1732167825@antos
Apparently this information has been outdated since first committed,
because we adopted a different implementation during development per
reviews and this detail was not updated in the README.
This has been wrong since commit 0ac5ad5134 introduced the file in
2013. Backpatch to all live branches.
Reported-by: Will Mortensen <will@extrahop.com>
Discussion: https://postgr.es/m/CAMpnoC6yEQ=c0Rdq-J7uRedrP7Zo9UMp6VZyP23QMT68n06cvA@mail.gmail.com
RelationSyncCache, the hash table in charge of tracking the relation
schemas sent through pgoutput, was forgetting to free the TupleDesc
associated to the two slots used to store the new and old tuples,
causing some memory to be leaked each time a relation is invalidated
when the slots of an existing relation entry are cleaned up.
This is rather hard to notice as the bloat is pretty minimal, but a
long-running WAL sender would be in trouble over time depending on the
workload. sysbench has proved to be pretty good at showing the problem,
coupled with some memory monitoring of the WAL sender.
Issue introduced in 52e4f0cd47, that has added row filters for tables
logically replicated.
Author: Boyu Yang
Reviewed-by: Michael Paquier, Hou Zhijie
Discussion: https://postgr.es/m/DM3PR84MB3442E14B340E553313B5C816E3252@DM3PR84MB3442.NAMPRD84.PROD.OUTLOOK.COM
Backpatch-through: 15
Ordinarily transformSetOperationTree will collect all UNION/
INTERSECT/EXCEPT steps into the setOperations tree of the topmost
Query, so that leaf queries do not contain any setOperations.
However, it cannot thus flatten a subquery that also contains
WITH, ORDER BY, FOR UPDATE, or LIMIT. I (tgl) forgot that in
commit 07b4c48b6 and wrote an assertion in rule deparsing that
a leaf's setOperations would always be empty.
If it were nonempty then we would want to parenthesize the subquery
to ensure that the output represents the setop nesting correctly
(e.g. UNION below INTERSECT had better get parenthesized). So
rather than just removing the faulty Assert, let's change it into
an additional case to check to decide whether to add parens. We
don't expect that the additional case will ever fire, but it's
cheap insurance.
Man Zeng and Tom Lane
Discussion: https://postgr.es/m/tencent_7ABF9B1F23B0C77606FC5FE3@qq.com
In the dim past we figured it was okay to ignore collations
when combining UNION set-operation nodes into a single N-way
UNION operation. I believe that was fine at the time, but
it stopped being fine when we added nondeterministic collations:
the semantics of distinct-ness are affected by those. v17 made
it even less fine by allowing per-child sorting operations to
be merged via MergeAppend, although I think we accidentally
avoided any live bug from that.
Add a check that collations match before deciding that two
UNION nodes are equivalent. I also failed to resist the
temptation to comment plan_union_children() a little better.
Back-patch to all supported branches (v13 now), since they
all have nondeterministic collations.
Discussion: https://postgr.es/m/3605568.1731970579@sss.pgh.pa.us
Commits aac2c9b4f et al. added a bool field to struct ResultRelInfo.
That's no problem in the master branch, but in released branches
care must be taken when modifying publicly-visible structs to avoid
an ABI break for extensions. Frequently we solve that by adding the
new field at the end of the struct, and that's what was done here.
But ResultRelInfo has stricter constraints than just about any other
node type in Postgres. Some executor APIs require extensions to index
into arrays of ResultRelInfo, which means that any change whatever in
sizeof(ResultRelInfo) causes a fatal ABI break.
Fortunately, this is easy to fix, because the new field can be
squeezed into available padding space instead --- indeed, that's where
it was put in master, so this fix also removes a cross-branch coding
variation.
Per report from Pavan Deolasee. Patch v14-v17 only; earlier versions
did not gain the extra field, nor is there any problem in master.
Discussion: https://postgr.es/m/CABOikdNmVBC1LL6pY26dyxAS2f+gLZvTsNt=2XbcyG7WxXVBBQ@mail.gmail.com
After commit 5a2fed911a, the catalog state
resulting from these commands ceased to affect sessions. Restore the
longstanding behavior, which is like beginning the session with a SET
ROLE command. If cherry-picking the CVE-2024-10978 fixes, default to
including this, too. (This fixes an unintended side effect of fixing
CVE-2024-10978.) Back-patch to v12, like that commit. The release team
decided to include v12, despite the original intent to halt v12 commits
earlier this week.
Tom Lane and Noah Misch. Reported by Etienne LAFARGE.
Discussion: https://postgr.es/m/CADOZwSb0UsEr4_UTFXC5k7=fyyK8uKXekucd+-uuGjJsGBfxgw@mail.gmail.com
Previously LogicalIncreaseRestartDecodingForSlot() accidentally
accepted any LSN as the candidate_lsn and candidate_valid after the
restart_lsn of the replication slot was updated, so it potentially
caused the restart_lsn to move backwards.
A scenario where this could happen in logical replication is: after a
logical replication restart, based on previous candidate_lsn and
candidate_valid values in memory, the restart_lsn advances upon
receiving a subscriber acknowledgment. Then, logical decoding restarts
from an older point, setting candidate_lsn and candidate_valid based
on an old RUNNING_XACTS record. Subsequent subscriber acknowledgments
then update the restart_lsn to an LSN older than the current value.
In the reported case, after WAL files were removed by a checkpoint,
the retreated restart_lsn prevented logical replication from
restarting due to missing WAL segments.
This change essentially modifies the 'if' condition to 'else if'
condition within the function. The previous code had an asymmetry in
this regard compared to LogicalIncreaseXminForSlot(), which does
almost the same thing for different fields.
The WAL removal issue was reported by Hubert Depesz Lubaczewski.
Backpatch to all supported versions, since the bug exists since 9.4
where logical decoding was introduced.
Reviewed-by: Tomas Vondra, Ashutosh Bapat, Amit Kapila
Discussion: https://postgr.es/m/Yz2hivgyjS1RfMKs%40depesz.com
Discussion: https://postgr.es/m/85fff40e-148b-4e86-b921-b4b846289132%40vondra.me
Backpatch-through: 13
Michael Paquier