The grammar IF NOT EXISTS for CTAS is supported since 9.5 and documented
as such, however the case of using EXECUTE as query has never been
covered as EXECUTE CTAS statements and normal CTAS statements are parsed
separately.
Author: Andreas Karlsson
Discussion: https://postgr.es/m/2ddcc188-e37c-a0be-32bf-a56b07c3559e@proxel.se
Backpatch-through: 9.5
DSM handle values can be reused as soon as the underlying shared memory
object has been destroyed. That means that for a brief moment we
might have two DSM slots with the same handle. While trying to attach,
if we encounter a slot with refcnt == 1, meaning that it is currently
being destroyed, we should continue our search in case the same handle
exists in another slot.
The race manifested as a rare "dsa_area could not attach to segment"
error, and was more likely in 10 and 11 due to the lack of distinct
seed for random() in parallel workers. It was made very unlikely in
in master by commit 197e4af9, and older releases don't usually create
new DSM segments in background workers so it was also unlikely there.
This fixes the root cause of bug report #15585, in which the error
could also sometimes result in a self-deadlock in the error path.
It's not yet clear if further changes are needed to avoid that failure
mode.
Back-patch to 9.4, where dsm.c arrived.
Author: Thomas Munro
Reported-by: Justin Pryzby, Sergei Kornilov
Discussion: https://postgr.es/m/20190207014719.GJ29720@telsasoft.com
Discussion: https://postgr.es/m/15585-324ff6a93a18da46@postgresql.org
In a corner case, a btree page was allocated during a clean-up operation
that could cause the tracking of the largest contiguous span of free
space to get out of whack. That was supposed to be prevented by the use
of the "soft" flag to avoid allocating internal pages during incidental
clean-up work, but the flag was ignored in the case where the FPM was
promoted from singleton format to btree format. Repair.
Remove an obsolete comment in passing.
Back-patch to 10, where freepage.c arrived (as support for dsa.c).
Author: Robert Haas
Diagnosed-by: Thomas Munro and Robert Haas
Reported-by: Justin Pryzby, Rick Otten, Sand Stone, Arne Roland and others
Discussion: https://postgr.es/m/CAMAYy4%2Bw3NTBM5JLWFi8twhWK4%3Dk_5L4nV5%2BbYDSPu8r4b97Zg%40mail.gmail.com
Ever since its birth, ReorderBufferBuildTupleCidHash() has contained an
assertion that a catalog tuple cannot change Cmax after acquiring one. But
that's wrong: if a subtransaction executes DDL that affects that catalog
tuple, and later aborts and another DDL affects the same tuple, it will
change Cmax. Relax the assertion to merely verify that the Cmax remains
valid and monotonically increasing, instead.
Add a test that tickles the relevant code.
Diagnosed by, and initial patch submitted by: Arseny Sher
Co-authored-by: Arseny Sher
Discussion: https://postgr.es/m/874l9p8hyw.fsf@ars-thinkpad
It's pretty unhelpful to report the wrong file name in a complaint
about syscall failure, but SnapBuildSerialize managed to do that twice
in a span of 50 lines. Also fix half a dozen missing or poorly-chosen
errcode assignments; that's mostly cosmetic, but still wrong.
Noted while studying recent failures on buildfarm member nightjar.
I'm not sure whether those reports are actually giving the wrong
filename, because there are two places here with identically
spelled error messages. The other one is specifically coded not
to report ENOENT, but if it's this one, how could we be getting
ENOENT from open() with O_CREAT? Need to sit back and await results.
However, these ereports are clearly broken from birth, so back-patch.
Renaming varchar_transform to varchar_support had a side effect
I hadn't foreseen: the core regression tests leave around a
transform object that relies on that function, so the name
change breaks cross-version upgrade tests, because the name
used in the older branches doesn't match.
Since the dependency on varchar_transform was chosen with the
aid of a dartboard anyway (it would surely not work as a
language transform support function), fix by just choosing
a different random builtin function with the right signature.
Also add some comments explaining why this isn't horribly unsafe.
I chose to make the same substitution in a couple of other
copied-and-pasted test cases, for consistency, though those
aren't directly contributing to the testing problem.
Per buildfarm. Back-patch, else it doesn't fix the problem.
warn_or_exit_horribly() was blithely passing a potentially-NULL
string pointer to a %s format specifier. That works (at least
to the extent of not crashing) on some platforms, but not all,
and since we switched to our own snprintf.c it doesn't work
for us anywhere.
Of the three string fields being handled this way here, I think
that only "owner" is supposed to be nullable ... but considering
that this is error-reporting code, it has very little business
assuming anything, so put in defenses for all three.
Per a crash observed on buildfarm member crake and then
reproduced here. Because of the portability aspect,
back-patch to all supported versions.
The previous ordering of these steps satisfied the nominal requirement
that set_rel_pathlist_hook could editorialize on the whole set of Paths
constructed for a base relation. In practice, though, trying to change
the set of partial paths was impossible. Adding one didn't work because
(a) it was too late to be included in Gather paths made by the core code,
and (b) calling add_partial_path after generate_gather_paths is unsafe,
because it might try to delete a path it thinks is dominated, but that
is already embedded in some Gather path(s). Nor could the hook safely
remove partial paths, for the same reason that they might already be
embedded in Gathers.
Better to call extensions first, let them add partial paths as desired,
and then gather. In v11 and up, we already doubled down on that ordering
by postponing gathering even further for single-relation queries; so even
if the hook wished to editorialize on Gather path construction, it could
not.
Report and patch by KaiGai Kohei. Back-patch to 9.6 where Gather paths
were added.
Discussion: https://postgr.es/m/CAOP8fzahwpKJRTVVTqo2AE=mDTz_efVzV6Get_0=U3SO+-ha1A@mail.gmail.com
While this isn't really supposed to happen, it can occur in OOM
situations and perhaps others. Instead of crashing, substitute
"(no message provided)".
I didn't worry about localizing this text, since we aren't
localizing anything else here; besides, if we're on the edge of
OOM, it's unlikely gettext() would work.
Report and fix by Sergio Conde Gómez in bug #15624.
Discussion: https://postgr.es/m/15624-4dea54091a2864e6@postgresql.org
As reported in bug #15613 from Srinivasan S A, file_fdw and postgres_fdw
neglected to mark plain baserel foreign paths as parameterized when the
relation has lateral_relids. Other FDWs have surely copied this mistake,
so rather than just patching those two modules, install a band-aid fix
in create_foreignscan_path to rectify the mistake centrally.
Although the band-aid is enough to fix the visible symptom, correct
the calls in file_fdw and postgres_fdw anyway, so that they are valid
examples for external FDWs.
Also, since the band-aid isn't enough to make this work for parameterized
foreign joins, throw an elog(ERROR) if such a case is passed to
create_foreignscan_path. This shouldn't pose much of a problem for
existing external FDWs, since it's likely they aren't trying to make such
paths anyway (though some of them may need a defense against joins with
lateral_relids, similar to the one this patch installs into postgres_fdw).
Add some assertions in relnode.c to catch future occurrences of the same
error --- in particular, as backstop against core-code mistakes like the
one fixed by commit bdd9a99aa.
Discussion: https://postgr.es/m/15613-092be1be9576c728@postgresql.org
The modules RewindTest.pm and ServerSetup.pm are really only useful for
TAP tests, so they really belong in the TAP test directories. In
addition, ServerSetup.pm is renamed to SSLServer.pm.
The test scripts have their own directories added to the search path so
that the relocated modules will be found, regardless of where the tests
are run from, even on modern perl where "." is no longer in the
searchpath.
Discussion: https://postgr.es/m/e4b0f366-269c-73c3-9c90-d9cb0f4db1f9@2ndQuadrant.com
Backpatch as appropriate to 9.5
create_lateral_join_info() computes a bunch of information about lateral
references between base relations, and then attempts to propagate those
markings to appendrel children of the original base relations. But the
original coding neglected the possibility of indirect descendants
(grandchildren etc). During v11 development we noticed that this was
wrong for partitioned-table cases, but failed to realize that it was just
as wrong for any appendrel. While the case can't arise for appendrels
derived from traditional table inheritance (because we make a flat
appendrel for that), nested appendrels can arise from nested UNION ALL
subqueries. Failure to mark the lower-level relations as having lateral
references leads to confusion in add_paths_to_append_rel about whether
unparameterized paths can be built. It's not very clear whether that
leads to any user-visible misbehavior; the lack of field reports suggests
that it may cause nothing worse than minor cost misestimation. Still,
it's a bug, and it leads to failures of Asserts that I intend to add
later.
To fix, we need to propagate information from all appendrel parents,
not just those that are RELOPT_BASERELs. We can still do it in one
pass, if we rely on the append_rel_list to be ordered with ancestor
relationships before descendant ones; add assertions checking that.
While fixing this, we can make a small performance improvement by
traversing the append_rel_list just once instead of separately for
each appendrel parent relation.
Noted while investigating bug #15613, though this patch does not fix
that (which is why I'm not committing the related Asserts yet).
Discussion: https://postgr.es/m/3951.1549403812@sss.pgh.pa.us
Commit f83419b739 failed to notice that mkvcbuild.pl and build.pl use
different searchpath and do-file logic, breaking the latter, so it is
adjusted to use the same logic as mkvcbuild.pl.
Contrary to the comment on 772d4b76, only paths starting with "./" or
"../" are considered relative to the current working directory by perl's
"do" function. So this patch converts all the relevant cases to use "./"
paths. This only affects MSVC.
Backpatch to all live branches.
DST law changes in Kazakhstan, Metlakatla, and São Tomé and Príncipe.
Kazakhstan's Qyzylorda zone is split in two, creating a new zone
Asia/Qostanay, as some areas did not change UTC offset.
Historical corrections for Hong Kong and numerous Pacific islands.
This was fixed for MSVC tools by commit 1df92eeafefac4, but per
buildfarm member bowerbird genbki.pl needs the same treatment.
Backpatch to all live branches.
Historically we've had each release branch include all prior branches'
notes, including minor-release changes, back to the beginning of the
project. That's basically an O(N^2) proposition, and it was starting to
catch up with us: as of HEAD the back-branch release notes alone accounted
for nearly 30% of the documentation. While there's certainly some value
in easy access to back-branch notes, this is getting out of hand.
Hence, switch over to the rule that each branch contains only its own
release notes. So as to not make older notes too hard to find, each
branch will provide URLs for the immediately preceding branches'
release notes on the project website.
There might be value in providing aggregated notes across all branches
somewhere on the website, but that's a task for another day.
Discussion: https://postgr.es/m/cbd4aeb5-2d9c-8b84-e968-9e09393d4c83@postgresql.org
Commit 62215de29 turns out to have been not quite on-the-mark.
When we are forced to postpone dumping of a materialized view into
the dump's post-data section (because it depends on a unique index
that isn't created till that section), we may also have to postpone
dumping other matviews that depend on said matview. The previous fix
didn't reliably work for such cases: it'd break the dependency loops
properly, producing a workable object ordering, but it didn't
necessarily mark all the matviews as "postponed_def". This led to
harmless bleating about "archive items not in correct section order",
as reported by Tom Cassidy in bug #15602. Less harmlessly,
selective-restore options such as --section might misbehave due to
the matview dump objects not being properly labeled.
The right way to fix it is to consider that each pre-data dependency
we break amounts to moving the no-longer-dependent object into
post-data, and hence we should mark that object if it's a matview.
Back-patch to all supported versions, since the issue's been there
since matviews were introduced.
Discussion: https://postgr.es/m/15602-e895445f73dc450b@postgresql.org
Rather than define ld_library_path_ver with a big nested $(if), just
put the overriding values in the makefiles for the relevant ports.
Also add a variable for port makefiles to append their own stuff to
with_temp_install, and use it to set LD_LIBRARY_PATH_RPATH=1 on
FreeBSD which is needed to make LD_LIBRARY_PATH override DT_RPATH
if DT_RUNPATH is not set (which seems to depend in unpredictable ways
on the choice of compiler, at least on my system).
Backpatch for the benefit of anyone doing regression tests on FreeBSD.
(For other platforms there should be no functional change.)
Add PG_CFLAGS, PG_CXXFLAGS, and PG_LDFLAGS variables to pgxs.mk which
will be appended or prepended to the corresponding make variables.
Notably, there was previously no way to pass custom CXXFLAGS to third
party extension module builds, COPT and PROFILE supporting only CFLAGS
and LDFLAGS.
Backpatch all the way down to ease integration with existing
extensions.
Author: Christoph Berg
Reviewed-by: Andres Freund, Tom Lane, Michael Paquier
Discussion: https://postgr.es/m/20181113104005.GA32154@msg.credativ.de
Backpatch-through: 9.4
To avoid deadlock, backend acquires a lock on heap pages in block
number order. In certain cases, lock on heap pages is dropped and
reacquired. In this case, the locks are dropped for reading in
corresponding VM page/s. The issue is we re-acquire locks in bufferId
order whereas the intention was to acquire in blockid order.
This commit ensures that we will always acquire locks on heap pages in
blockid order.
Reported-by: Nishant Fnu
Author: Nishant Fnu
Reviewed-by: Amit Kapila and Robert Haas
Backpatch-through: 9.4
Discussion: https://postgr.es/m/5883C831-2ED1-47C8-BFAC-2D5BAE5A8CAE@amazon.com
When logging the replica identity of a deleted tuple, XLOG_HEAP_DELETE
records include references of the old tuple. Its data is stored in an
intermediate variable used to register this information for the WAL
record, but this variable gets away from the stack when the record gets
actually inserted.
Spotted by clang's AddressSanitizer.
Author: Stas Kelvish
Discussion: https://postgr.es/m/085C8825-AD86-4E93-AF80-E26CDF03D1EA@postgrespro.ru
Backpatch-through: 9.4
The bug was that determining which columns are part of the replica
identity index using RelationGetIndexAttrBitmap() would run
eval_const_expressions() on index expressions and predicates across
all indexes of the table, which in turn might require a snapshot, but
there wasn't one set, so it crashes. There were actually two separate
bugs, one on the publisher and one on the subscriber.
To trigger the bug, a table that is part of a publication or
subscription needs to have an index with a predicate or expression
that lends itself to constant expressions simplification.
The fix is to avoid the constant expressions simplification in
RelationGetIndexAttrBitmap(), so that it becomes safe to call in these
contexts. The constant expressions simplification comes from the
calls to RelationGetIndexExpressions()/RelationGetIndexPredicate() via
BuildIndexInfo(). But RelationGetIndexAttrBitmap() calling
BuildIndexInfo() is overkill. The latter just takes pg_index catalog
information, packs it into the IndexInfo structure, which former then
just unpacks again and throws away. We can just do this directly with
less overhead and skip the troublesome calls to
eval_const_expressions(). This also removes the awkward
cross-dependency between relcache.c and index.c.
Bug: #15114
Reported-by: Петър Славов <pet.slavov@gmail.com>
Reviewed-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://www.postgresql.org/message-id/flat/152110589574.1223.17983600132321618383@wrigleys.postgresql.org/
Previously, \g would successfully execute the COPY command, but
the target specification if any was ignored, so that the data was
always dumped to the regular query output target. This seems like
a clear bug, so let's not just fix it but back-patch it.
While at it, adjust the documentation for \copy to recommend
"COPY ... TO STDOUT \g foo" as a plausible alternative.
Back-patch to 9.5. The problem exists much further back, but the
code associated with \g was refactored enough in 9.5 that we'd
need a significantly different patch for 9.4, and it doesn't
seem worth the trouble.
Daniel Vérité, reviewed by Fabien Coelho
Discussion: https://postgr.es/m/15dadc39-e050-4d46-956b-dcc4ed098753@manitou-mail.org
Since LISTEN is (still) disallowed, UNLISTEN must be a no-op in a
hot-standby session, and so there's no harm in allowing it. This
change allows client code to not worry about whether it's connected
to a primary or standby server when performing session-state-reset
type activities. (Note that DISCARD ALL, which includes UNLISTEN,
was already allowed, making it inconsistent to reject UNLISTEN.)
Per discussion, back-patch to all supported versions.
Shay Rojansky, reviewed by Mi Tar
Discussion: https://postgr.es/m/CADT4RqCf2gA_TJtPAjnGzkC3ZiexfBZiLmA-mV66e4UyuVv8bA@mail.gmail.com
A report from Andrew Dunstan showed that an ecpglib breakage that
causes repeated query failures could lead to infinite loops in some
ecpg test scripts, because they contain "while(1)" loops with no
exit condition other than successful test completion. That might
be all right for manual testing, but it seems entirely unacceptable
for automated test environments such as our buildfarm. We don't
want buildfarm owners to have to intervene manually when a test
goes wrong.
To fix, just change all those while(1) loops to exit after at most
100 iterations (which is more than any of them expect to iterate).
This seems sufficient since we'd see discrepancies in the test output
if any loop executed the wrong number of times.
I tested this by dint of intentionally breaking ecpg_do_prologue
to always fail, and verifying that the tests still got to completion.
Back-patch to all supported branches, since the whole point of this
exercise is to protect the buildfarm against future mistakes.
Discussion: https://postgr.es/m/18693.1548302004@sss.pgh.pa.us
Apparently, some builds of MinGW contain a version of
_configthreadlocale() that always returns -1, indicating failure.
Rather than treating that as a curl-up-and-die condition, soldier on
as though the function didn't exist. This leaves us without thread
safety on such MinGW versions, but we didn't have it anyway.
Discussion: https://postgr.es/m/d06a16bc-52d6-9f0d-2379-21242d7dbe81@2ndQuadrant.com
ecpglib attempts to force the LC_NUMERIC locale to "C" while reading
server output, to avoid problems with strtod() and related functions.
Historically it's just issued setlocale() calls to do that, but that
has major problems if we're in a threaded application. setlocale()
itself is not required by POSIX to be thread-safe (and indeed is not,
on recent OpenBSD). Moreover, its effects are process-wide, so that
we could cause unexpected results in other threads, or another thread
could change our setting.
On platforms having uselocale(), which is required by POSIX:2008,
we can avoid these problems by using uselocale() instead. Windows
goes its own way as usual, but we can make it safe by using
_configthreadlocale(). Platforms having neither continue to use the
old code, but that should be pretty much nobody among current systems.
(Subsequent buildfarm results show that recent NetBSD versions still
lack uselocale(), but it's not a big problem because they also do not
support non-"C" settings for LC_NUMERIC.)
Back-patch of commits 8eb4a9312 and ee27584c4.
Michael Meskes and Tom Lane; thanks also to Takayuki Tsunakawa.
Discussion: https://postgr.es/m/31420.1547783697@sss.pgh.pa.us
Back in commit 100340e2dcd0, we made relcache entries keep lists of the
foreign keys applying to the relation -- but we forgot to update
CacheInvalidateHeapTuple to flush those entries when new FKs got created
or existing ones updated/deleted. No bugs appear to have been reported
that would be explained by this ommission, but I noticed the problem
while working on an unrelated bugfix which clearly showed it. Fix by
adding relcache flush on relevant foreign key changes.
Backpatch to 9.6, like the aforementioned commit.
Discussion: https://postgr.es/m/201901211927.7mmhschxlejh@alvherre.pgsql
Reviewed-by: Tom Lane
This reverts commit 5b16a353543ecec36ffda68269defb7b1b002f60.
Per discussion, it's not desirable to add valgrind suppressions for
outside our own code base (e.g. glibc in this case), especially when
the suppressions may be platform-specific. There are better ways to
deal with that, e.g. by providing local suppressions.
Discussion: https://www.postgresql.org/message-id/flat/90ac0452-e907-e7a4-b3c8-15bd33780e62%402ndquadrant.com
Recent OpenBSD (at least 5.9 and up) has a version of getopt(3)
that will not cope with the "-:" spec we use to accept double-dash
options in postgres.c and postmaster.c. Admittedly, that's a hack
because POSIX only requires getopt() to allow alphanumeric option
characters. I have no desire to find another way, however, so
let's just do what we were already doing on Solaris: force use
of our own src/port/getopt.c implementation.
In passing, improve some of the comments around said implementation.
Per buildfarm and local testing. Back-patch to all supported branches.
Discussion: https://postgr.es/m/30197.1547835700@sss.pgh.pa.us
current_schema() gets called in the recently-added regression test from
c5660e0, and can be used in a parallel context, causing its call to fail
when creating a temporary schema.
Per buildfarm members crake and lapwing.
Discussion: https://postgr.es/m/20190118005949.GD1883@paquier.xyz
Attempting to use a temporary table within a two-phase transaction is
forbidden for ages. However, there have been uncovered grounds for
a couple of other object types and commands which work on temporary
objects with two-phase commit. In short, trying to create, lock or drop
an object on a temporary schema should not be authorized within a
two-phase transaction, as it would cause its state to create
dependencies with other sessions, causing all sorts of side effects with
the existing session or other sessions spawned later on trying to use
the same temporary schema name.
Regression tests are added to cover all the grounds found, the original
report mentioned function creation, but monitoring closer there are many
other patterns with LOCK, DROP or CREATE EXTENSION which are involved.
One of the symptoms resulting in combining both is that the session
which used the temporary schema is not able to shut down completely,
waiting for being able to drop the temporary schema, something that it
cannot complete because of the two-phase transaction involved with
temporary objects. In this case the client is able to disconnect but
the session remains alive on the backend-side, potentially blocking
connection backend slots from being used. Other problems reported could
also involve server crashes.
This is back-patched down to v10, which is where 9b013dc has introduced
MyXactFlags, something that this patch relies on.
Reported-by: Alexey Bashtanov
Author: Michael Paquier
Reviewed-by: Masahiko Sawada
Discussion: https://postgr.es/m/5d910e2e-0db8-ec06-dd5f-baec420513c3@imap.cc
Backpatch-through: 10
Previously, parseCheckAggregates was run before
assign_query_collations, but this causes problems if any expression
has already had a collation assigned by some transform function (e.g.
transformCaseExpr) before parseCheckAggregates runs. The differing
collations would cause expressions not to be recognized as equal to
the ones in the GROUP BY clause, leading to spurious errors about
unaggregated column references.
The result was that CASE expr WHEN val ... would fail when "expr"
contained a GROUPING() expression or matched one of the group by
expressions, and where collatable types were involved; whereas the
supposedly identical CASE WHEN expr = val ... would succeed.
Backpatch all the way; this appears to have been wrong ever since
collations were introduced.
Per report from Guillaume Lelarge, analysis and patch by me.
Discussion: https://postgr.es/m/CAECtzeVSO_US8C2Khgfv54ZMUOBR4sWq+6_bLrETnWExHT=rFg@mail.gmail.com
Discussion: https://postgr.es/m/87muo0k0c7.fsf@news-spur.riddles.org.uk
These have been found while cross-checking for the use of unique words
in the documentation, and a wait event was not getting generated in a way
consistent to what the documentation provided.
Author: Alexander Lakhin
Discussion: https://postgr.es/m/9b5a3a85-899a-ae62-dbab-1e7943aa5ab1@gmail.com
