Some of the test_decoding test output was extremely wide, because it
deals with massive toasted values, and the aligned mode causes psql to
produce 200kB of whitespace and dashes. Change to unaligned mode
temporarily to avoid that behavior.
Backpatch to 14, where it applies cleanly.
Discussion: https://postgr.es/m/20230405103953.sxleixp3uz5lazst@alvherre.pgsql
Because PostgreSQL::Version is very nuanced about development version
numbers, the comparison to 16beta2 makes it think that that release is
older than 16, therefore applying a database tweak that doesn't work
there (the comparison is only supposed to match when run on version 15).
As suggested by Andrew Dunstan, fix by having AdjustUpgrade.pm public
methods create a separate PostgreSQL::Version object to use for these
comparisons, that only carries the major version number.
While at it, have the same methods ensure that the objects given are of
the expected type.
Backpatch to 16. This module goes all the way back to 9.2, but there's
probably no need for this fix except where betas still live.
Co-authored-by: Andrew Dunstan <andrew@dunslane.net>
Discussion: https://postgr.es/m/20230719110504.zbu74o54bqqlsufb@alvherre.pgsql
After 3c90dcd03, try_partitionwise_join's child_joinrelids
variable is read only in an Assert, provoking a compiler
warning in non-assert builds. Rearrange code to avoid the
warning and eliminate unnecessary work in the non-assert case.
Per CI testing (via Jeff Davis and Bharath Rupireddy)
Discussion: https://postgr.es/m/ef0de9713e605451f1b60b30648c5ee900b2394c.camel@j-davis.com
Applying add_outer_joins_to_relids() to a child join doesn't actually
work, even if we've built a SpecialJoinInfo specialized to the child,
because that function will also compare the join's relids to elements
of the main join_info_list, which only deal in regular relids not
child relids. This mistake escaped detection by the existing
partitionwise join tests because they didn't test any cases where
add_outer_joins_to_relids() needs to add additional OJ relids (that
is, any cases where join reordering per identity 3 is possible).
Instead, let's apply adjust_child_relids() to the relids of the parent
join. This requires minor code reordering to collect the relevant
AppendRelInfo structures first, but that's work we'd do shortly anyway.
Report and fix by Richard Guo; cosmetic changes by me
Discussion: https://postgr.es/m/CAMbWs49NCNbyubZWgci3o=_OTY=snCfAPtMnM-32f3mm-K-Ckw@mail.gmail.com
A CaseTestExpr is currently being put into
JsonValueExpr.formatted_expr as placeholder for the result of
evaluating JsonValueExpr.raw_expr, which in turn is evaluated
separately. Though, there's no need for this indirection if
raw_expr itself can be embedded into formatted_expr and evaluated
as part of evaluating the latter, especially as there is no
special reason to evaluate it separately. So this commit makes it
so. As a result, JsonValueExpr.raw_expr no longer needs to be
evaluated in ExecInterpExpr(), eval_const_exprs_mutator() etc. and
is now only used for displaying the original "unformatted"
expression in ruleutils.c. Comments about and the code manipulating
formatted_expr is updated to mention that it is now always set and
is the expression that gives a JsonValueExpr its runtime value.
While at it, this also removes the function makeCaseTestExpr(),
because the code in makeJsonConstructorExpr() looks more readable
without it IMO and isn't used by anyone else either.
Finally, a note is added in the comment above CaseTestExpr's
definition that JsonConstructorExpr is also using it.
Backpatched to 16 from the development branch to keep the code in
sync across branches.
Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/CA+HiwqE4XTdfb1nW=Ojoy_tQSRhYt-q_kb6i5d4xcKyrLC1Nbg@mail.gmail.com
If both the passed-in plan pointer and plansource->gplan are
NULL, CachedPlanIsSimplyValid would think that the plan pointer
is possibly-valid and try to dereference it. For the one extant
call site in plpgsql, this situation doesn't normally happen
which is why we've not noticed. However, it appears to be possible
if the previous use of the cached plan failed, as per report from
Justin Pryzby. Add an extra check to prevent crashing.
Back-patch to v13 where this code was added.
Discussion: https://postgr.es/m/ZLlV+STFz1l/WhAQ@telsasoft.com
This allows it to pass to coerce_to_specific_type() the actual name
corresponding to the specific JSON_* function expression being
transformed, instead of the currently hardcoded string.
Backpatched to 16 from the development branch to keep the code in
sync across branches.
Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/CA+HiwqHu58pO3cJ7rB6ZLwUztVdG1J66xSjDdjfan5uT5NhESw@mail.gmail.com
With the addition of INHERIT and SET options for role grants,
the historical display of role memberships in \du/\dg is woefully
inadequate. Besides those options, there are pre-existing
shortcomings that you can't see the ADMIN option nor the grantor.
To fix this, remove the "Member of" column from \du/\dg altogether
(making that output usefully narrower), and invent a new meta-command
"\drg" that is specifically for displaying role memberships. It
shows one row for each role granted to the selected role(s), with
the grant options and grantor.
We would not normally back-patch such a feature addition post
feature freeze, but in this case the change is mainly driven by
v16 changes in the server, so it seems appropriate to include it
in v16.
Pavel Luzanov, with bikeshedding and review from a lot of people,
but particularly David Johnston
Discussion: https://postgr.es/m/b9be2d0e-a9bc-0a30-492f-a4f68e4f7740@postgrespro.ru
IN and NOT IN work fine on records and arrays, so just say that
they accept "expressions" not "scalar expressions". I think that
that phrasing was meant to say that they don't work on set-returning
expressions, but that's not the common meaning of "scalar".
Revise the description of row-constructor comparisons to make it
perhaps a bit less confusing. (This partially reverts some
dubious wording changes made by commit f56651519.)
Per gripe from Ilya Nenashev. Back-patch to supported branches.
In HEAD and v16, also drop a NOTE about pre-8.2 behavior, which
is hopefully no longer of interest to anybody.
Discussion: https://postgr.es/m/168968062460.632.14303906825812821399@wrigleys.postgresql.org
The "count" argument of SPI_exec() only limits execution when
the query is actually returning rows. This was not the case
before PG 9.0, so this example was correct when written; but
we missed updating it in commit 2ddc600f8. Extend the example
to show the behavior both with and without RETURNING.
While here, improve the commentary and markup for the rest
of the example.
David G. Johnston and Tom Lane, per report from Curt Kolovson.
Back-patch to all supported branches.
Discussion: https://postgr.es/m/CANhYJV6HWtgz_qjx_APfK0PAgLUzY-2vjLuj7i_o=TZF1LAQew@mail.gmail.com
This has been missed in cb0cca1, noticed before buildfarm member koel
has been able to complain while poking at a different patch. Like the
other commit, backpatch all the way down to limit the odds of merge
conflicts.
Backpatch-through: 11
A crash in the middle of a checkpoint with some two-phase state data
already flushed to disk by this checkpoint could cause a follow-up crash
recovery to recover twice the same transaction, once from what has been
found in pg_twophase/ at the beginning of recovery and a second time
when replaying its corresponding record.
This would lead to FATAL failures in the startup process during
recovery, where the same transaction would have a state recovered twice
instead of once:
LOG: recovering prepared transaction 731 from shared memory
LOG: recovering prepared transaction 731 from shared memory
FATAL: lock ExclusiveLock on object 731/0/0 is already held
This issue is fixed by skipping the addition of any 2PC state coming
from a record whose equivalent 2PC state file has already been loaded in
TwoPhaseState at the beginning of recovery by restoreTwoPhaseData(),
which is OK as long as the system has not reached a consistent state.
The timing to get a messed up recovery processing is very racy, and
would very unlikely happen. The thread that has reported the issue has
demonstrated the bug using injection points to force a PANIC in the
middle of a checkpoint.
Issue introduced in 728bd99, so backpatch all the way down.
Reported-by: "suyu.cmj" <mengjuan.cmj@alibaba-inc.com>
Author: "suyu.cmj" <mengjuan.cmj@alibaba-inc.com>
Author: Michael Paquier
Discussion: https://postgr.es/m/109e6994-b971-48cb-84f6-829646f18b4c.mengjuan.cmj@alibaba-inc.com
Backpatch-through: 11
fe-auth.c references CHAR_BIT since commit 3a465cc67, but it
did not #include <limits.h>, which per POSIX is where that
symbol is defined. This escaped notice so far because
(a) on most platforms, <sys/param.h> pulls in <limits.h>,
(b) even if yours doesn't, OpenSSL pulls it in, so compiling
with --with-openssl masks the omission.
Per bug #18026 from Marcel Hofstetter. Back-patch to v16.
Discussion: https://postgr.es/m/18026-d5bb69f79cd16203@postgresql.org
In a61b1f7482, we failed to update transformFromClauseItem() and
buildNSItemFromLists() to set ParseNamespaceItem.p_perminfo causing
it to point to garbage.
Pointed out by Tom Lane.
Reported-by: Farias de Oliveira <matheusfarias519@gmail.com>
Discussion: https://postgr.es/m/3173476.1689286373%40sss.pgh.pa.us
Backpatch-through: 16
RelationReloadIndexInfo() is a fast-path used for index reloads in the
relation cache, and it has always forgotten about updating
indisreplident, which is something that would happen after an index is
selected for a replica identity. This can lead to incorrect cache
information provided when executing a command in a transaction context
that updates indisreplident.
None of the code paths currently on HEAD that need to check upon
pg_index.indisreplident fetch its value from the relation cache, always
relying on a fresh copy on the syscache. Unfortunately, this may not be
the case of out-of-core code, that could see out-of-date value.
Author: Shruthi Gowda
Reviewed-by: Robert Haas, Dilip Kumar, Michael Paquier
Discussion: https://postgr.es/m/CAASxf_PBcxax0wW-3gErUyftZ0XrCs3Lrpuhq4-Z3Fak1DoW7Q@mail.gmail.com
Backpatch-through: 11
indisvalid is switched to true for partitioned indexes when all its
partitions have valid indexes when attaching a new partition, up to the
top-most parent if all its leaves are themselves valid when dealing with
multiple layers of partitions.
The copy of the tuple from pg_index used to switch indisvalid to true
came from the relation cache, which is incorrect. Particularly, in the
case reported by Shruthi Gowda, executing a series of commands in a
single transaction would cause the validation of partitioned indexes to
use an incorrect version of a pg_index tuple, as indexes are reloaded
after an invalidation request with RelationReloadIndexInfo(), a much
faster version than a full index cache rebuild. In this case, the
limited information updated in the cache leads to an incorrect version
of the tuple used. One of the symptoms reported was the following
error, with a replica identity update, for instance:
"ERROR: attempted to update invisible tuple"
This is incorrect since 8b08f7d, so backpatch all the way down.
Reported-by: Shruthi Gowda
Author: Michael Paquier
Reviewed-by: Shruthi Gowda, Dilip Kumar
Discussion: https://postgr.es/m/CAASxf_PBcxax0wW-3gErUyftZ0XrCs3Lrpuhq4-Z3Fak1DoW7Q@mail.gmail.com
Backpatch-through: 11
Until now, when DROP DATABASE got interrupted in the wrong moment, the removal
of the pg_database row would also roll back, even though some irreversible
steps have already been taken. E.g. DropDatabaseBuffers() might have thrown
out dirty buffers, or files could have been unlinked. But we continued to
allow connections to such a corrupted database.
To fix this, mark databases invalid with an in-place update, just before
starting to perform irreversible steps. As we can't add a new column in the
back branches, we use pg_database.datconnlimit = -2 for this purpose.
An invalid database cannot be connected to anymore, but can still be
dropped.
Unfortunately we can't easily add output to psql's \l to indicate that some
database is invalid, it doesn't fit in any of the existing columns.
Add tests verifying that a interrupted DROP DATABASE is handled correctly in
the backend and in various tools.
Reported-by: Evgeny Morozov <postgresql3@realityexists.net>
Author: Andres Freund <andres@anarazel.de>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Thomas Munro <thomas.munro@gmail.com>
Discussion: https://postgr.es/m/20230509004637.cgvmfwrbht7xm7p6@awork3.anarazel.de
Discussion: https://postgr.es/m/20230314174521.74jl6ffqsee5mtug@awork3.anarazel.de
Backpatch: 11-, bug present in all supported versions
When vac_truncate_clog() encounters bogus datfrozenxid / datminmxid values, it
returns early. Unfortunately, until now, it did not release
WrapLimitsVacuumLock. If the backend later tries to acquire
WrapLimitsVacuumLock, the session / autovacuum worker hangs in an
uncancellable way. Similarly, other sessions will hang waiting for the
lock. However, if the backend holding the lock exited or errored out for some
reason, the lock was released.
The bug was introduced as a side effect of 566372b3d6.
It is interesting that there are no production reports of this problem. That
is likely due to a mix of bugs leading to bogus values having gotten less
common, process exit releasing locks and instances of hangs being hard to
debug for "normal" users.
Discussion: https://postgr.es/m/20230621221208.vhsqgduwfpzwxnpg@awork3.anarazel.de
GiST compress functions (like all GiST opclass functions) are
supposed to be called in short-lived memory contexts, so that
minor memory leaks in them are not of concern, and indeed
explicit pfree's are likely slightly counterproductive.
But this one in g_intbig_compress() is more than
slightly counterproductive, because it's guarded by
"if (in != DatumGetArrayTypeP(entry->key))" which means
that if this test succeeds, we've detoasted the datum twice.
(And to add insult to injury, the extra detoast result is
leaked.) Let's just drop the whole stanza, relying on the
GiST temporary context mechanism to clean up in good time.
The analogous bit in g_int_compress() is
if (r != (ArrayType *) DatumGetPointer(entry->key))
pfree(r);
which doesn't have the gratuitous-detoast problem so
I left it alone. Perhaps there is a case for removing
unnecessary pfree's more widely, but I'm not sure if it's
worth the code churn.
The potential extra decompress seems expensive enough to
justify calling this a (minor) performance bug and
back-patching.
Konstantin Knizhnik, Matthias van de Meent, Tom Lane
Discussion: https://postgr.es/m/CAEze2Wi86=DxErfvf+SCB2UKmU2amKOF60BKuJOX=w-RojRn0A@mail.gmail.com
Commit 89e46da5e allowed REPLICA IDENTITY FULL tables to use an index
on the subscriber during apply of update/delete. This commit clarifies
in the documentation that the leftmost field of candidate indexes must
be a column (not an expression) that references the published relation
column.
The source code comments are also updated accordingly.
Reviewed-by: Peter Smith, Amit Kapila
Discussion: https://postgr.es/m/CAD21AoDJjffEvUFKXT27Q5U8-UU9JHv4rrJ9Ke8Zkc5UPWHLvA@mail.gmail.com
Backpatch-through: 16
In the event the llvm option is defined to be 'auto', it is possible
that the host machine might not have a C++ compiler. If that is the
case, then we shouldn't continue reaching for the llvm dependency.
To make it easier to understand the case where LLVM support is disabled due to
lacking a C++ compiler, add a message noting that fact.
Author: Tristan Partin <tristan@neon.tech>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CSPIJVUDZFKX.3KHMOAVGF94RV@c3po
Backpatch: 16-, where meson support was added
That was already done in a lot of places, but not all.
Backpatch this to keep the the meson files aligned as long as reasonably
possible.
Author: Tristan Partin <tristan@neon.tech>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CSPIJVUDZFKX.3KHMOAVGF94RV@c3po
Backpatch: 16-, where meson support was added
Since PostgresMain calls sigsetjmp, any local variables that are not
marked "volatile" have a risk of unspecified behavior. In practice
this means that when control returns via longjmp, such variables might
get reset to their values as of the time of sigsetjmp, depending on
whether the compiler chose to put them in registers or on the stack.
We were careful about this for "send_ready_for_query", but not the
other local variables.
In the case of the timeout_enabled flags, resetting them to
their initial "false" states is actually good, since we do
"disable_all_timeouts()" in the longjmp cleanup code path. If that
does not happen, we risk uselessly calling "disable_timeout()" later,
which is harmless but a little bit expensive. Let's explicitly reset
these flags so that the behavior is correct and platform-independent.
(This change means that we really don't need the new "volatile"
markings after all, but let's install them anyway since any change
in this logic could re-introduce a problem.)
There is no issue for "firstchar" and "input_message" because those
are explicitly reinitialized each time through the query processing
loop. To make that clearer, move them to be declared inside the loop.
That leaves us with all the function-lifespan locals except the
sigjmp_buf itself marked as volatile, which seems like a good policy
to have going forward.
Because of the possibility of extra disable_timeout() calls, this
seems worth back-patching.
Sergey Shinderuk and Tom Lane
Discussion: https://postgr.es/m/2eda015b-7dff-47fd-d5e2-f1a9899b90a6@postgrespro.ru
As coded, the code would use as a base comparison the namespace OID from
the first object scanned in pg_depend when switching its namespace
dependency entry to the new one, and use it as a base of comparison for
any follow-up checks. It would also be used as the old namespace OID to
switch *from* for the extension's pg_depend entry. Hence, if the first
object scanned has a namespace different than the one stored in the
extension, we would finish by:
- Not checking that the extension objects map with the extension's
schema.
- Not switching the extension -> namespace dependency entry to the new
namespace provided by the user, making ALTER EXTENSION ineffective.
This issue exists since this command has been introduced in d9572c4 for
relocatable extension, so backpatch all the way down to 11. The test
case has been provided by Heikki, that I have tweaked a bit to show the
effects on pg_depend for the extension.
Reported-by: Heikki Linnakangas
Author: Michael Paquier, Heikki Linnakangas
Discussion: https://postgr.es/m/20eea594-a05b-4c31-491b-007b6fceef28@iki.fi
Backpatch-through: 11
The DEFAULT parameter seems most similar to the NULL parameter, so
move it next to it, instead of having it at the end of the parameter
list because it was the last one added.
Commit e213de8e78 fixed a problem with path lengths to a tempdir on
Windows, but caused problems on at least some Unix systems where the
system tempdir is on a different file system. To work around this, only
used the system temdir for the destination of pg_replslot on Windows,
and otherwise restore the old behaviour.
Backpatch to relase 14 like the previous patch.
Problem exposed by a myriad of buildfarm animals.
The symlink to a longer location tripped up some Windows limit on
buildfarm animal fairywren when running with meson, which uses slightly
longer paths.
Backpatch to all live branches to keep the script in sync.
Commit 19d8e2308b allowed a weaker check for HOT with summarizing
indexes, but it did not update README.HOT. So do that now.
Patch by Matthias van de Meent, minor changes by me. Backpatch to 16,
where the optimization was introduced.
Author: Matthias van de Meent
Reviewed-by: Tomas Vondra
Backpatch-through: 16
Discussion: https://postgr.es/m/CAEze2WiEOm8V+c9kUeYp2BPhbEc5s473fUf51xNeqvSFGv44Ew@mail.gmail.com
On Windows, it's sometimes difficult to create a file with a path longer
than 255 chars, and if it can be created it might not be seen by the
archiver. This can be triggered by the test for tar backups with
filenames greater than 100 bytes. So we skip that test if the path would
exceed 255.
Backpatch to all live branches.
Reviewed by Daniel Gustafsson
Discussion: https://postgr.es/m/666ac55b-3400-fb2c-2cea-0281bf36a53c@dunslane.net
We create a file, so we better WAL-log it. In practice, all the
built-in index AMs and all extensions that I'm aware of write a
metapage to the init fork, which is WAL-logged, and replay of the
metapage implicitly creates the fork too. But if ambuildempty() didn't
write any page, we would miss it.
This can be seen with dummy_index_am. Set up replication, create a
'dummy_index_am' index on an unlogged table, and look at the files
created in the replica: the init fork is not created on the
replica. Dummy_index_am doesn't do anything with the relation files,
however, so it doesn't lead to any user-visible errors.
Backpatch to all supported versions.
Reviewed-by: Robert Haas
Discussion: https://www.postgresql.org/message-id/6e5bbc08-cdfc-b2b3-9e23-1a914b9850a9%40iki.fi
This commit reverts the work done by commits 3ba59ccc89 and 72e78d831a.
Those commits were incorrect in asserting that we never acquire any other
heavy-weight lock after acquring page lock other than relation extension
lock. We can acquire a lock on catalogs while doing catalog look up after
acquring page lock.
This won't impact any existing feature but we need to think some other way
to achieve this before parallelizing other write operations or even
improving the parallelism in vacuum (like allowing multiple workers
for an index).
Reported-by: Jaime Casanova
Author: Amit Kapila
Backpatch-through: 13
Discussion: https://postgr.es/m/CAJKUy5jffnRKNvRHKQ0LynRb0RJC-o4P8Ku3x9vGAVLwDBWumQ@mail.gmail.com
llvm_release_context() called llvm_enter_fatal_on_oom(), but was missing
the corresponding llvm_leave_fatal_on_oom() call. As a result, if JIT was
used at all, we were almost always in the "fatal-on-oom" state.
It only makes a difference if you use an extension written in C++, and
run out of memory in a C++ 'new' call. In that case, you would get a
PostgreSQL FATAL error, instead of the default behavior of throwing a
C++ exception.
Back-patch to all supported versions.
Reviewed-by: Daniel Gustafsson
Discussion: https://www.postgresql.org/message-id/54b78cca-bc84-dad8-4a7e-5b56f764fab5@iki.fi
Commit 7b64e4b3 taught DropSubscription() to drop stats entry of
subscription that is not associated with a replication slot for apply
worker at DROP SUBSCRIPTION but missed covering the case where the
subscription is not associated with replication slots for both apply
worker and tablesync worker.
Also add a test to verify that the stats for slot-less subscription is
removed at DROP SUBSCRIPTION time.
Backpatch down to 15.
Author: Masahiko Sawada
Reviewed-by: Nathan Bossart, Hayato Kuroda, Melih Mutlu, Amit Kapila
Discussion: https://postgr.es/m/CAD21AoB71zkP7uPT7JDPsZcvp0749ExEQnOJxeNKPDFisHar+w@mail.gmail.com
Backpatch-through: 15
Clear any potential stale next_phase_at value from the snapshot
builder which otherwise may trip an assertion check ensuring
that there is no next_phase_at value.
This can be reproduced by running 80 concurrent sessions like
the below where $c is a loop counter (assumes there has been
1..$c databases created) :
echo "
CREATE TABLE replication_example(id SERIAL PRIMARY KEY,
somedata int,
text varchar(120));
SELECT 'init' FROM
pg_create_logical_replication_slot('regression_slot_$c',
'test_decoding');
SELECT data FROM
pg_logical_slot_get_changes('regression_slot_$c', NULL,
NULL, 'include-xids', '0',
'skip-empty-xacts', '1');
" | psql -d regress_$c >>psql.log &
Backpatch down to v16.
Bug: #17695
Author: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Alexander Lakhin <exclusion@gmail.com>
Reported-by: bowenshi <zxwsbg@qq.com>
Discussion: https://postgr.es/m/17695-6be9277c9295985f@postgresql.org
Backpatch-through: v16
If you create a table and don't insert any data into it, the relation file
is never fsync'd. You don't lose data, because an empty table doesn't have
any data to begin with, but if you crash and lose the file, subsequent
operations on the table will fail with "could not open file" error.
To fix, register an fsync request in mdcreate(), like we do for mdwrite().
Per discussion, we probably should also fsync the containing directory
after creating a new file. But that's a separate and much wider issue.
Backpatch to all supported versions.
Reviewed-by: Andres Freund, Thomas Munro
Discussion: https://www.postgresql.org/message-id/d47d8122-415e-425c-d0a2-e0160829702d%40iki.fi
It's OK to be lazy about re-binning memory segments when allocating,
because that can only leave segments in a bin that's too high. We'll
search higher bins if necessary while allocating next time, and
also eventually re-bin, so no memory can become unreachable that way.
However, when freeing memory, the largest contiguous range of free pages
might go up, so we should re-bin eagerly to make sure we don't leave the
segment in a bin that is too low for get_best_segment() to find.
The re-binning code is moved into a function of its own, so it can be
called whenever free pages are returned to the segment's free page map.
Back-patch to all supported releases.
Author: Dongming Liu <ldming101@gmail.com>
Reviewed-by: Robert Haas <robertmhaas@gmail.com> (earlier version)
Reviewed-by: Thomas Munro <thomas.munro@gmail.com>
Discussion: https://postgr.es/m/CAL1p7e8LzB2LSeAXo2pXCW4%2BRya9s0sJ3G_ReKOU%3DAjSUWjHWQ%40mail.gmail.com
The ginfast.c code previously checked for conflicts in before locking
the relevant buffer, leaving a window where a RW conflict could be
missed. Re-order.
There was also a place where buffer ID and block number were confused
while trying to predicate-lock a page, noted by visual inspection.
Back-patch to all supported releases. Fixes one more problem discovered
with the reproducer from bug #17949, in this case when Dmitry tried
other index types.
Reported-by: Artem Anisimov <artem.anisimov.255@gmail.com>
Reported-by: Dmitry Dolgov <9erthalion6@gmail.com>
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Discussion: https://postgr.es/m/17949-a0f17035294a55e2%40postgresql.org
When performing a bitmap heap scan, we don't want to miss concurrent
writes that occurred after we observed the heap's rs_nblocks, but before
we took predicate locks on index pages. Therefore, we can't skip
fetching any heap tuples that are referenced by the index, because we
need to test them all with CheckForSerializableConflictOut(). The
old optimization that would ignore any references to blocks >=
rs_nblocks gets in the way of that requirement, because it means that
concurrent writes in that window are ignored.
Removing that optimization shouldn't affect correctness at any isolation
level, because any new tuples shouldn't be visible to an MVCC snapshot.
There also shouldn't be any error-causing references to heap blocks past
the end, because we should have held at least an AccessShareLock on the
table before the index scan. It can't get smaller while our transaction
is running. For now, though, we'll keep the optimization at lower
levels to avoid making unnecessary changes in a bug fix.
Back-patch to all supported releases. In release 11, the code is in a
different place but not fundamentally different. Fixes one aspect of
bug #17949.
Reported-by: Artem Anisimov <artem.anisimov.255@gmail.com>
Reviewed-by: Dmitry Dolgov <9erthalion6@gmail.com>
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Discussion: https://postgr.es/m/17949-a0f17035294a55e2%40postgresql.org
When predicate-locking btrees, we have a special case for completely
empty btrees, since there is no page to lock. This was racy, because,
without buffer lock held, a matching key could be inserted between the
_bt_search() and the PredicateLockRelation() calls.
Fix, by rechecking _bt_search() after taking the relation-level SIREAD
lock, if using SERIALIZABLE isolation and an empty btree is discovered.
Back-patch to all supported releases. Fixes one aspect of bug #17949.
Reported-by: Artem Anisimov <artem.anisimov.255@gmail.com>
Reviewed-by: Dmitry Dolgov <9erthalion6@gmail.com>
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Discussion: https://postgr.es/m/17949-a0f17035294a55e2%40postgresql.org
The test inserted 70k rows into a foreign table, in order to verify
correct behavior with more than 65535 parameters, and was added in
response to a bug report.
However, this is rather expensive, especially when running the tests
under valgrind, CLOBBER_CACHE_ALWAYS etc. It doesn't seem worth it to
keep running the test, so remove it from all branches (14+).
Backpatch-through: 14
Discussion: https://postgr.es/m/2131017.1623451468@sss.pgh.pa.us
Alvaro Herrera