The arguments of the function were listed in an incorrect order in the
description of the routine. This information can be seen with perldoc.
Issue spotted while working on this area of the code.
Backpatch-through: 17
After repartitioning the inner side of a hash join that would have
exceeded the allowed size, we check if all the tuples from a parent
partition moved to one child partition. That is evidence that it
contains duplicate keys and later attempts to repartition will also
fail, so we should give up trying to limit memory (for lack of a better
fallback strategy).
A thinko prevented the check from working correctly in partition 0 (the
one that is partially loaded into memory already). After
repartitioning, we should check for extreme skew if the *parent*
partition's space_exhausted flag was set, not the child partition's.
The consequence was repeated futile repartitioning until per-partition
data exceeded various limits including "ERROR: invalid DSA memory alloc
request size 1811939328", OS allocation failure, or temporary disk space
errors. (We could also do something about some of those symptoms, but
that's material for separate patches.)
This problem only became likely when PostgreSQL 16 introduced support
for Parallel Hash Right/Full Join, allowing NULL keys into the hash
table. Repartitioning always leaves NULL in partition 0, no matter how
many times you do it, because the hash value is all zero bits. That's
unlikely for other hashed values, but they might still have caused
wasted extra effort before giving up.
Back-patch to all supported releases.
Reported-by: Craig Milhiser <craig@milhiser.com>
Reviewed-by: Andrei Lepikhov <lepihov@gmail.com>
Discussion: https://postgr.es/m/CA%2BwnhO1OfgXbmXgC4fv_uu%3DOxcDQuHvfoQ4k0DFeB0Qqd-X-rQ%40mail.gmail.com
This commit adds missing checks for COPY FORCE_NOT_NULL and FORCE_NULL
when applied to all columns via "*". These options now correctly
require CSV mode and are disallowed in COPY TO, making their behavior
consistent with FORCE_QUOTE.
Some regression tests are added to verify the correct behavior for the
all-columns case, including FORCE_QUOTE, which was not tested.
Backpatch down to 17, where support for the all-column grammar with
FORCE_NOT_NULL and FORCE_NULL has been added.
Author: Joel Jacobson
Reviewed-by: Zhang Mingli
Discussion: https://postgr.es/m/65030d1d-5f90-4fa4-92eb-f5f50389858e@app.fastmail.com
Backpatch-through: 17
Some queries in copy2 are there to check various option combinations,
and used "stdin" or "stdout" incompatible with the COPY TO or FROM
clauses combined with them, which was confusing. This commit rewrites
these queries to use a compatible grammar.
The coverage of the tests is unchanged. Like the original commit
451d1164b9d0, backpatch down to 16 where these have been introduced. A
follow-up commit will rely on this area of the tests for a bug fix.
Author: Joel Jacobson
Reviewed-by: Zhang Mingli
Discussion: https://postgr.es/m/65030d1d-5f90-4fa4-92eb-f5f50389858e@app.fastmail.com
Backpatch-through: 16
Commit 2dc1deaea turns out to have been still a brick shy of a load,
because CALL statements executing within a plpgsql exception block
could still pass the wrong snapshot to stable functions within the
CALL's argument list. That happened because standard_ProcessUtility
forces isAtomicContext to true if IsTransactionBlock is true, which
it always will be inside a subtransaction. Then ExecuteCallStmt
would think it does not need to push a new snapshot --- but
_SPI_execute_plan didn't do so either, since it thought it was in
nonatomic mode.
The best fix for this seems to be for _SPI_execute_plan to operate
in atomic execution mode if IsSubTransaction() is true, even when the
SPI context as a whole is non-atomic. This makes _SPI_execute_plan
have the same rules about when non-atomic execution is allowed as
_SPI_commit/_SPI_rollback have about when COMMIT/ROLLBACK are allowed,
which seems appropriately symmetric. (If anyone ever tries to allow
COMMIT/ROLLBACK inside a subtransaction, this would all need to be
rethought ... but I'm unconvinced that such a thing could be logically
consistent at all.)
For further consistency, also check IsSubTransaction() in
SPI_inside_nonatomic_context. That does not matter for its
one present-day caller StartTransaction, which can't be reached
inside a subtransaction. But if any other callers ever arise,
they'd presumably want this definition.
Per bug #18656 from Alexander Alehin. Back-patch to all
supported branches, like previous fixes in this area.
Discussion: https://postgr.es/m/18656-cade1780866ef66c@postgresql.org
Commit a4ccc1cef introduced the Generation Context and modified the
logical decoding process to use a Generation Context with a fixed
block size of 8MB for storing tuple data decoded during logical
decoding (i.e., rb->tup_context). Several reports have indicated that
the logical decoding process can be terminated due to
out-of-memory (OOM) situations caused by excessive memory usage in
rb->tup_context.
This issue can occur when decoding a workload involving several
concurrent transactions, including a long-running transaction that
modifies tuples. By design, the Generation Context does not free a
memory block until all chunks within that block are
released. Consequently, if tuples modified by the long-running
transaction are stored across multiple memory blocks, these blocks
remain allocated until the long-running transaction completes, leading
to substantial memory fragmentation. The memory usage during logical
decoding, tracked by rb->size, does not account for memory
fragmentation, resulting in potentially much higher memory consumption
than the value of the logical_decoding_work_mem parameter.
Various improvement strategies were discussed in the relevant
thread. This change reduces the block size of the Generation Context
used in rb->tup_context from 8MB to 8kB. This modification
significantly decreases the likelihood of substantial memory
fragmentation occurring and is relatively straightforward to
backport. Performance testing across multiple platforms has confirmed
that this change will not introduce any performance degradation that
would impact actual operation.
Backport to all supported branches.
Reported-by: Alex Richman, Michael Guissine, Avi Weinberg
Reviewed-by: Amit Kapila, Fujii Masao, David Rowley
Tested-by: Hayato Kuroda, Shlok Kyal
Discussion: https://postgr.es/m/CAD21AoBTY1LATZUmvSXEssvq07qDZufV4AF-OHh9VD2pC0VY2A%40mail.gmail.com
Backpatch-through: 12
Attempting to use an interval of time less than 1ms would cause \watch
to hang. This was confusing, so let's change the logic so as an
interval lower than 1ms behaves the same as 0.
Comments are added to mention that the internals of do_watch() had
better rely on "sleep_ms", the interval value in milliseconds. While on
it, this commit adds a test to check the behavior of interval values
less than 1ms.
\watch hanging for interval values less than 1ms existed before
6f9ee74d45aa, that has changed the code to support an interval value of
0.
Reported-by: Heikki Linnakangas
Author: Andrey M. Borodin, Michael Paquier
Discussion: https://postgr.es/m/88445e0e-3156-4b9d-afae-9a1a7b1631f6@iki.fi
Backpatch-through: 16
find_computable_ec_member() had the wrong mental model of what
its primary caller prepare_sort_from_pathkeys() would do with
the selected EquivalenceClass member expression. We will not
compute the EC expression in a plan node atop the one returning
the passed-in targetlist; rather, the EC expression will be
computed as an additional column of that targetlist. So any
Var or quasi-Var used in the given tlist is also available to the
EC expression. In simple cases this makes no difference because
the given tlist is just a list of Vars or quasi-Vars --- but if
we are considering an appendrel member produced by flattening
a UNION ALL, the tlist may contain expressions, resulting in
failure to match and a "could not find pathkey item to sort"
error.
To fix, we can flatten both the tlist and the EC members with
pull_var_clause(), and then just check for subset-ness, so
that the code is actually shorter than before.
While this bug is quite old, the present patch only works back to
v13. We could possibly make it work in v12 by back-patching parts
of 375398244. On the whole though I don't like the risk/reward
ratio of that idea. v12's final release is next month, meaning
there would be no chance to correct matters if the patch causes a
regression. Since this failure has escaped notice for 14 years,
it's likely nobody will hit it in the field with v12.
Per bug #18652 from Alexander Lakhin.
Andrei Lepikhov and Tom Lane
Discussion: https://postgr.es/m/18652-deaa782ebcca85d1@postgresql.org
A missed check for the builtin collation provider could result in
falling through to call isalpha().
This does not appear to have practical consequences because it only
happens for characters in the ASCII range. Regardless, the builtin
provider should not be calling libc functions, so backpatch.
Discussion: https://postgr.es/m/1bd5a0a5192f82c22ee7527e825b18ab0028b2c7.camel@j-davis.com
Backpatch-through: 17
Commit 9391f7152 added a "PlannerInfo *root" parameter to
estimate_array_length, but failed to consider the possibility that
NULL would be passed for that, leading to a null pointer dereference.
We could rectify the particular case shown in the bug report by fixing
simplify_function/inline_function to pass through the root pointer.
However, as long as eval_const_expressions is documented to accept
NULL for root, similar hazards would remain. For now, let's just do
the narrow fix of hardening estimate_array_length to not crash.
Its behavior with NULL root will be the same as it was before
9391f7152, so this is not too awful.
Per report from Fredrik Widlert (via Paul Ramsey). Back-patch to v17
where 9391f7152 came in.
Discussion: https://postgr.es/m/518339E7-173E-45EC-A0FF-9A4A62AA4F40@cleverelephant.ca
Commit 149ac7d4559 which re-implemented pgindent in Perl explicitly
imported the devnull function from File::Spec, but the module does
not export anything. In recent versions of Perl calling a missing
import function cause a warning, which combined with warnings being
fatal cause pgindent to error out.
Backpatch to all supported versions.
Author: Erik Wienhold <ewie@ewie.name>
Reviewed-by: Andrew Dunstan <andrew@dunslane.net>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discusson: https://postgr.es/m/2372cd74-11b0-46f9-b28e-8f9627215d19@ewie.name
Backpatch-through: v12
The test was unstable in branches 14 and 15 as we were relying on the
number of changes in the table having a toast column to start streaming.
On branches >= 16, we have a GUC debug_logical_replication_streaming which
can stream each change, so the test was stable in those branches.
Change the test to use PREPARE TRANSACTION as that should make the result
consistent and test the code changed in 022564f60c.
Reported-by: Daniel Gustafsson as per buildfarm
Author: Hou Zhijie, Amit Kapila
Backpatch-through: 14
Discussion: https://postgr.es/m/8C2F86AA-981E-4803-B14D-E264C0255330@yesql.se
Commit 1ab67c9dfa, which modified this catalog query so that it
doesn't return temporary relations, forgot to schema-qualify the
operator. A comment earlier in the function implores us to fully
qualify everything in the query:
* Since we execute the constructed query with the default search_path
* (which could be unsafe), everything in this query MUST be fully
* qualified.
This commit fixes that. While at it, add a newline for consistency
with surrounding code.
Reviewed-by: Noah Misch
Discussion: https://postgr.es/m/ZwQJYcuPPUsF0reU%40nathan
Backpatch-through: 12
Several places treat MyStartTime as a "long", which is only 32 bits
wide on some platforms. In reality, MyStartTime is a pg_time_t,
i.e., a signed 64-bit integer. This will lead to interesting bugs
on the aforementioned systems in 2038 when signed 32-bit integers
are no longer sufficient to store Unix time (e.g., "pg_ctl start"
hanging). To fix, ensure that MyStartTime is handled as a 64-bit
value everywhere. (Of course, users will need to ensure that
time_t is 64 bits wide on their system, too.)
Co-authored-by: Max Johnson
Discussion: https://postgr.es/m/CO1PR07MB905262E8AC270FAAACED66008D682%40CO1PR07MB9052.namprd07.prod.outlook.com
Backpatch-through: 12
During logical decoding of in-progress transactions, we perform the toast
table scan while fetching the default toast value for an attribute. We
forgot to initialize the flag during this scan to indicate that the system
table scan is in progress. We need this flag to ensure that during logical
decoding we never directly access the tableam or heap APIs because we check
for concurrent aborts only in systable_* APIs.
Reported-by: Alexander Lakhin
Author: Takeshi Ideriha, Hou Zhijie
Reviewed-by: Amit Kapila, Hou Zhijie
Backpatch-through: 14
Discussion: https://postgr.es/m/18641-6687273b7f15269d@postgresql.org
pg_cursor() supposed that any Portal it finds in the hash table must
have sourceText set up, but there's an edge case where that is not so.
A newly-created Portal has sourceText = NULL, and that doesn't change
until PortalDefineQuery is called. In SPI_cursor_open_internal,
we perform GetCachedPlan between CreatePortal and PortalDefineQuery,
and it's possible for user-defined code to execute during that
planning and cause a fetch from the pg_cursors view, resulting in a
null-pointer-dereference crash. (It looks like the same could happen
in exec_bind_message, but I've not tried to provoke a failure there.)
I considered trying to fix this by setting sourceText sooner, but
there may be instances of this same calling pattern in extensions,
and we couldn't be sure they'd get the memo promptly. It seems
better to redefine pg_cursor as not showing Portals that have
not yet had PortalDefineQuery called on them, which we can do by
just skipping them if sourceText is still NULL.
(Before a1c692358, pg_cursor would instead return a row with NULL
in the statement column. We could revert to that behavior but it
doesn't really seem like a better definition, especially since our
documentation doesn't suggest that the column could be NULL.)
Per report from PetSerAl. Back-patch to all supported branches.
Discussion: https://postgr.es/m/CAKygsHTBXLXjwV43kpZa+Cs+XTiaeeJiZdL4cPBm9f4MTdw7wg@mail.gmail.com
When instantiating an existing partitioned index for a new child
partition, we use generateClonedIndexStmt to build a suitable
IndexStmt to pass to DefineIndex. However, when DefineIndex needs
to recurse to instantiate a newly created partitioned index on an
existing child partition, it was doing copyObject on the given
IndexStmt and then applying a bunch of ad-hoc fixups. This has
a number of problems, primarily that it implies fresh lookups of
referenced objects such as opclasses and collations. Since commit
2af07e2f7 caused DefineIndex to restrict search_path internally, those
lookups could fail or deliver different results than the original one.
We can avoid those problems and save a few dozen lines of code by
using generateClonedIndexStmt in this code path too.
Another thing this fixes is incorrect propagation of parent-index
comments to child indexes (because the copyObject approach copies
the idxcomment field while generateClonedIndexStmt doesn't). I had
noticed this in connection with commit c01eb619a, but not run the
problem to ground.
I'm tempted to back-patch this further than v17, but the only thing
it's known to fix in older branches is the comment issue, which is
pretty minor and doesn't seem worth the risk of introducing new
issues in stable branches. (If anyone does care about that,
clearing idxcomment in the copied IndexStmt would be a safer fix.)
Per bug #18637 from usamoi. Back-patch to v17 where the search_path
change came in.
Discussion: https://postgr.es/m/18637-f51e314546e3ba2a@postgresql.org
Commit bf03cfd1 started scanning all available BCP 47 locale names on
Windows. This caused an abort/crash in the Windows runtime library if
the default locale name contained non-ASCII characters, because of our
use of the setlocale() save/restore pattern with "char" strings. After
switching to another locale with a different encoding, the saved name
could no longer be understood, and setlocale() would abort.
"Turkish_Türkiye.1254" is the example from recent reports, but there are
other examples of countries and languages with non-ASCII characters in
their names, and they appear in Windows' (old style) locale names.
To defend against this:
1. In initdb, reject non-ASCII locale names given explicity on the
command line, or returned by the operating system environment with
setlocale(..., ""), or "canonicalized" by the operating system when we
set it.
2. In initdb only, perform the save-and-restore with Windows'
non-standard wchar_t variant of setlocale(), so that it is not subject
to round trip failures stemming from char string encoding confusion.
3. In the backend, we don't have to worry about the save-and-restore
problem because we have already vetted the defaults, so we just have to
make sure that CREATE DATABASE also rejects non-ASCII names in any new
databases. SET lc_XXX doesn't suffer from the problem, but the ban
applies to it too because it uses check_locale(). CREATE COLLATION
doesn't suffer from the problem either, but it doesn't use
check_locale() so it is not included in the new ban for now, to minimize
the change.
Anyone who encounters the new error message should either create a new
duplicated locale with an ASCII-only name using Windows Locale Builder,
or consider using BCP 47 names like "tr-TR". Users already couldn't
initialize a cluster with "Turkish_Türkiye.1254" on PostgreSQL 16+, but
the new failure mode is an error message that explains why, instead of a
crash.
Back-patch to 16, where bf03cfd1 landed. Older versions are affected
in theory too, but only 16 and later are causing crash reports.
Reviewed-by: Andrew Dunstan <andrew@dunslane.net> (the idea, not the patch)
Reported-by: Haifang Wang (Centific Technologies Inc) <v-haiwang@microsoft.com>
Discussion: https://postgr.es/m/PH8PR21MB3902F334A3174C54058F792CE5182%40PH8PR21MB3902.namprd21.prod.outlook.com
If a MERGE command contains WHEN NOT MATCHED BY SOURCE actions, the
source relation appears on the outer side of the join. Thus, any Vars
referring to the source in the merge join condition, actions, and
RETURNING list should be marked as nullable by the join, since they
are used in the ModifyTable node above the join. Note that this only
applies to the copy of join condition used in the executor to
distinguish MATCHED from NOT MATCHED BY SOURCE cases. Vars in the
original join condition, inside the join node itself, should not be
marked.
Failure to correctly mark these Vars led to a "wrong varnullingrels"
error in the final stage of query planning, in some circumstances. We
happened to get away without this in all previous tests, since they
all involved a ModifyTable node directly on top of the join node, so
that the top plan targetlist coincided with the output of the join,
and the varnullingrels check was more lax. However, if another plan
node, such as a one-time filter Result node, gets inserted between the
ModifyTable node and the join node, then a stricter check is applied,
which fails.
Per bug #18634 from Alexander Lakhin. Thanks to Tom Lane and Richard
Guo for review and analysis.
Back-patch to v17, where WHEN NOT MATCHED BY SOURCE support was added
to MERGE.
Discussion: https://postgr.es/m/18634-db5299c937877f2b%40postgresql.org
If a MERGE command contains WHEN NOT MATCHED BY SOURCE actions, the
merge join condition is used by the executor to distinguish MATCHED
from NOT MATCHED BY SOURCE cases. However, this qual is executed using
the output from the join subplan node, which nulls the output from the
source relation in the not matched case, and so the result may be
incorrect if the join condition is "non-strict" -- for example,
something like "src.col IS NOT DISTINCT FROM tgt.col".
Fix this by enhancing the join recheck condition with an additional
"src IS NOT NULL" check, so that it does the right thing when
evaluated using the output from the join subplan.
Noted by Tom Lane while investigating bug #18634 from Alexander
Lakhin.
Back-patch to v17, where WHEN NOT MATCHED BY SOURCE support was added
to MERGE.
Discussion: https://postgr.es/m/18634-db5299c937877f2b%40postgresql.org
Use pqParseIntParam (nee parse_int_param) instead of using strtol
directly. This allows trailing whitespace, which the previous coding
didn't, and makes the spelling of the error message consistent with
other similar cases.
This seems to be an oversight in commit e7a221797, which introduced
parse_int_param. That fixed places that were using atoi(), but missed
this place which was randomly using strtol() instead.
Ordinarily I'd consider this minor cleanup not worth back-patching.
However, it seems that ecpg assumes it can add trailing whitespace
to URL parameters, so that use of the keepalives option fails in
that context. Perhaps that's worth improving as a separate matter.
In the meantime, back-patch this to all supported branches.
Yuto Sasaki (some further cleanup by me)
Discussion: https://postgr.es/m/TY2PR01MB36286A7B97B9A15793335D18C1772@TY2PR01MB3628.jpnprd01.prod.outlook.com
The fork name is always separated with the block number by an underscore
in the names of the files generated, but the docs stuck them together
without a separator, which was confusing.
Author: Christoph Berg
Discussion: https://postgr.es/m/ZvxtSLiix9eceMRM@msg.df7cb.de
Backpatch-through: 16
There were unnecessary non-breaking spaces (nbsp, U+00A0, 0xc2a0 in
UTF-8) in the docs. This commit replaces them with ASCII spaces
(0x20).
config.sgml is backpatched through 17.
ref/drop_extension.sgml is backpatched through 13.
Discussion: https://postgr.es/m/20240930.153404.202479334310259810.ishii%40postgresql.org
Reviewed-by: Yugo Nagata, Daniel Gustafsson
Backpatch-through: 17, 13
COMMIT PREPARED removes on-disk 2PC files near its end, but the state
checked if a file is on-disk or not gets read from shared memory while
not holding the two-phase state lock.
Because of that, there was a small window where a second backend doing a
PREPARE TRANSACTION could reuse the GlobalTransaction put back into the
2PC free list by the COMMIT PREPARED, overwriting the "ondisk" flag read
afterwards by the COMMIT PREPARED to decide if its on-disk two-phase
state file should be removed, preventing the file deletion.
This commit fixes this issue so as the "ondisk" flag in the
GlobalTransaction is read while holding the two-phase state lock, not
from shared memory after its entry has been added to the free list.
Orphaned two-phase state files flushed to disk after a checkpoint are
discarded at the beginning of recovery. However, a truncation of
pg_xact/ would make the startup process issue a FATAL when it cannot
read the SLRU page holding the state of the transaction whose 2PC file
was orphaned, which is a necessary step to decide if the 2PC file should
be removed or not. Removing manually the file would be necessary in
this case.
Issue introduced by effe7d9552dd, so backpatch all the way down.
Mea culpa.
Author: wuchengwen
Discussion: https://postgr.es/m/tencent_A7F059B5136A359625C7B2E4A386B3C3F007@qq.com
Backpatch-through: 12
For some reason this listed "-f" and "-w" as valid switches, though
the code doesn't implement any such thing nor do the docs mention
them. The effect of this was that if you tried to use one of these
switches, you'd get an unhelpful error message.
Yusuke Sugie
Discussion: https://postgr.es/m/68e72a2a70f4d84c1c7847b13bcdaef8@oss.nttdata.com
Reindexing temp tables or indexes of other sessions is not allowed.
However, reindexdb in parallel mode previously listed them as
the objects to process, leading to failures.
This commit ensures reindexdb in parallel mode skips temporary tables
and indexes by adding a condition based on the relpersistence column
in pg_class to the object listing queries, preventing these issues.
Note that this commit does not affect reindexdb when temporary tables
or indexes are explicitly specified using the -t or -j options;
reindexdb in that case still does not skip them and can cause an error.
Back-patch to v13 where parallel mode was introduced in reindexdb.
Author: Fujii Masao
Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/5f37ee56-14fb-44fe-9150-9eb97e10538b@oss.nttdata.com
Defect in last week's commit aac2c9b4fde889d13f859c233c2523345e72d32b,
per Coverity. Reaching this would need catalog corruption. Back-patch
to v12, like that commit.
Since v17, CREATE MATERIALIZED VIEW has set search_path to
"pg_catalog, pg_temp" while running the query. The docs for the
other commands that restrict search_path mention it, but the page
for CREATE MATERIALIZED VIEW does not. Fix that.
Oversight in commit 4b74ebf726.
Author: Yugo Nagata
Reviewed-by: Jeff Davis
Discussion: https://postgr.es/m/20240805160502.d2a4975802a832b1e04afb80%40sraoss.co.jp
Backpatch-through: 17
An invalid toast index is skipped in reindex_relation(). These would be
remnants of a failed REINDEX CONCURRENTLY and they should never been
rebuilt as there can only be one valid toast index at a time.
REINDEX_REL_SUPPRESS_INDEX_USE, used by CLUSTER and VACUUM FULL, needs
to maintain a list of the indexes being processed. The list of indexes
is retrieved from the relation cache, and includes invalid indexes. The
code has missed that invalid toast indexes are ignored in
reindex_relation() as this leads to a hard failure in reindex_index(),
and they were left in the reindex pending list, making the list
inconsistent when rechecked. The incorrect memory access was happening
when scanning pg_class for the refresh of pg_database.datfrozenxid, when
doing a scan of pg_class.
This issue exists since REINDEX CONCURRENTLY exists, where invalid toast
indexes can exist, so backpatch all the way down.
Reported-by: Alexander Lakhin
Author: Tender Wang
Discussion: https://postgr.es/m/18630-9aed99c38830657d@postgresql.org
Backpatch-through: 12
There's no need to add another level of indentation to this status
message. pg_log() will put it in the right place.
Oversight in commit 347758b120.
Reviewed-by: Daniel Gustafsson
Discussion: https://postgr.es/m/ZunW7XHLd2uTts4f%40nathan
Backpatch-through: 17
Running vacuumdb with a non-superuser while another user has created a
temporary table would lead to a mid-flight permission failure,
interrupting the operation. vacuum_rel() skips temporary relations of
other backends, and it makes no sense for vacuumdb to know about these
relations, so let's switch it to ignore temporary relations entirely.
Adding a qual in the query based on relpersistence simplifies the
generation of its WHERE clause in vacuum_one_database(), per se the
removal of "has_where".
Author: VaibhaveS, Michael Paquier
Reviewed-by: Fujii Masao
Discussion: https://postgr.es/m/CAM_eQjwfAR=y3G1fGyS1U9FTmc+FyJm9amNfY2QCZBnDDbNPZg@mail.gmail.com
Backpatch-through: 12
The previous commit fixed some ways of losing an inplace update. It
remained possible to lose one when a backend working toward a
heap_update() copied a tuple into memory just before inplace update of
that tuple. In catalogs eligible for inplace update, use LOCKTAG_TUPLE
to govern admission to the steps of copying an old tuple, modifying it,
and issuing heap_update(). This includes MERGE commands. To avoid
changing most of the pg_class DDL, don't require LOCKTAG_TUPLE when
holding a relation lock sufficient to exclude inplace updaters.
Back-patch to v12 (all supported versions). In v13 and v12, "UPDATE
pg_class" or "UPDATE pg_database" can still lose an inplace update. The
v14+ UPDATE fix needs commit 86dc90056dfdbd9d1b891718d2e5614e3e432f35,
and it wasn't worth reimplementing that fix without such infrastructure.
Reviewed by Nitin Motiani and (in earlier versions) Heikki Linnakangas.
Discussion: https://postgr.es/m/20231027214946.79.nmisch@google.com
As previously-added tests demonstrated, heap_inplace_update() could
instead update an unrelated tuple of the same catalog. It could lose
the update. Losing relhasindex=t was a source of index corruption.
Inplace-updating commands like VACUUM will now wait for heap_update()
commands like GRANT TABLE and GRANT DATABASE. That isn't ideal, but a
long-running GRANT already hurts VACUUM progress more just by keeping an
XID running. The VACUUM will behave like a DELETE or UPDATE waiting for
the uncommitted change.
For implementation details, start at the systable_inplace_update_begin()
header comment and README.tuplock. Back-patch to v12 (all supported
versions). In back branches, retain a deprecated heap_inplace_update(),
for extensions.
Reported by Smolkin Grigory. Reviewed by Nitin Motiani, (in earlier
versions) Heikki Linnakangas, and (in earlier versions) Alexander
Lakhin.
Discussion: https://postgr.es/m/CAMp+ueZQz3yDk7qg42hk6-9gxniYbp-=bG2mgqecErqR5gGGOA@mail.gmail.com
The current use always releases this locktag. A planned use will
continue that intent. It will involve more areas of code, making unlock
omissions easier. Warn under debug_assertions, like we do for various
resource leaks. Back-patch to v12 (all supported versions), the plan
for the commit of the new use.
Reviewed by Heikki Linnakangas.
Discussion: https://postgr.es/m/20240512232923.aa.nmisch@google.com
Commit d1379ebf4 carelessly broke printACLColumn for pre-9.4 servers,
by using the cardinality() function which we introduced in 9.4.
We expect psql's describe-related commands to work back to 9.2, so
this is bad. Use the longstanding array_length() function instead.
Per report from Christoph Berg. Back-patch to v17.
Discussion: https://postgr.es/m/ZvLXYglRS6hMMhtr@msg.df7cb.de
