Michael Paquier [Fri, 5 Apr 2019 01:38:47 +0000 (10:38 +0900)]
Fix some documentation in pg_rewind
A confusion which comes a lot from users is that it is necessary to
issue a checkpoint on a freshly-promoted standby so as its control file
has up-to-date timeline information which is used by pg_rewind to
validate the operation. Let's document that properly. This is
back-patched down to 9.5 where pg_rewind has been introduced.
Author: Michael Paquier Reviewed-by: Magnus Hagander
Discussion: https://postgr.es/m/CABUevEz5bpvbwVsYCaSMV80CBZ5-82nkMzbb+Bu=h1m=rLdn=g@mail.gmail.com
Backpatch-through: 9.5
Handle USE_MODULE_DB for all tests able to use an installed postmaster.
When $(MODULES) and $(MODULE_big) are empty, derive the database name
from the first element of $(REGRESS) instead of using a constant string.
When deriving the database name from $(MODULES), use its first element
instead of the entire list; the earlier approach would fail if any
multi-module directory had $(REGRESS) tests. Treat isolation suites and
src/pl correspondingly. Under USE_MODULE_DB=1, installcheck-world and
check-world no longer reuse any database name in a given postmaster.
Buildfarm members axolotl, mandrill and frogfish saw spurious "is being
accessed by other users" failures that would not have happened without
database name reuse. (The CountOtherDBBackends() 5s deadline expired
during DROP DATABASE; a backend for an earlier test suite had used the
same database name and had not yet exited.) Back-patch to 9.4 (all
supported versions), except bits pertaining to isolation suites.
Concept reviewed by Andrew Dunstan, Andres Freund and Tom Lane.
postmaster startup scrutinizes any shared memory segment recorded in
postmaster.pid, exiting if that segment matches the current data
directory and has an attached process. When the postmaster.pid file was
missing, a starting postmaster used weaker checks. Change to use the
same checks in both scenarios. This increases the chance of a startup
failure, in lieu of data corruption, if the DBA does "kill -9 `head -n1
postmaster.pid` && rm postmaster.pid && pg_ctl -w start". A postmaster
will no longer recycle segments pertaining to other data directories.
That's good for production, but it's bad for integration tests that
crash a postmaster and immediately delete its data directory. Such a
test now leaks a segment indefinitely. No "make check-world" test does
that. win32_shmem.c already avoided all these problems. In 9.6 and
later, enhance PostgresNode to facilitate testing. Back-patch to 9.4
(all supported versions).
Reviewed by Daniel Gustafsson and Kyotaro HORIGUCHI.
Dean Rasheed [Tue, 2 Apr 2019 07:22:48 +0000 (08:22 +0100)]
Perform RLS subquery checks as the right user when going via a view.
When accessing a table with RLS via a view, the RLS checks are
performed as the view owner. However, the code neglected to propagate
that to any subqueries in the RLS checks. Fix that by calling
setRuleCheckAsUser() for all RLS policy quals and withCheckOption
checks for RTEs with RLS.
One should almost always terminate an old process, not use a manual
removal tool like ipcrm. Removal of the ipcclean script eleven years
ago (39627b1ae680cba44f6e56ca5facec4fdbfe9495) and its non-replacement
corroborate that manual shm removal is now a niche goal. Back-patch to
9.4 (all supported versions).
Reviewed by Daniel Gustafsson and Kyotaro HORIGUCHI.
Tomas Vondra [Wed, 27 Mar 2019 01:39:39 +0000 (02:39 +0100)]
Track unowned relations in doubly-linked list
Relations dropped in a single transaction are tracked in a list of
unowned relations. With large number of dropped relations this resulted
in poor performance at the end of a transaction, when the relations are
removed from the singly linked list one by one.
Commit b4166911 attempted to address this issue (particularly when it
happens during recovery) by removing the relations in a reverse order,
resulting in O(1) lookups in the list of unowned relations. This did
not work reliably, though, and it was possible to trigger the O(N^2)
behavior in various ways.
Instead of trying to remove the relations in a specific order with
respect to the linked list, which seems rather fragile, switch to a
regular doubly linked. That allows us to remove relations cheaply no
matter where in the list they are.
As b4166911 was a bugfix, backpatched to all supported versions, do the
same thing here.
Tom Lane [Sun, 24 Mar 2019 19:13:21 +0000 (15:13 -0400)]
Avoid double-free in vacuumlo error path.
The code would do "PQclear(res)" twice if lo_unlink failed, evidently
due to careless thinking about how far out a "break" would break.
Remove the extra PQclear and adjust the loop logic so that we'll fall
out of both levels of loop after an error, as was clearly the intent.
Spotted by Coverity. I have no idea why it took this long to notice,
since the bug has been there since commit 67ccbb080. Accordingly,
back-patch to all supported branches.
Fix WAL format incompatibility introduced by backpatching of 52ac6cd2d0
52ac6cd2d0 added new field to ginxlogDeletePage and was backpatched to 9.4.
That led to problems when patched postgres instance applies WAL records
generated by non-patched one. WAL records generated by non-patched instance
don't contain new field, which patched one is expecting to see.
Thankfully, we can distinguish patched and non-patched WAL records by their data
size. If we see that WAL record is generated by non-patched instance, we skip
processing of new field. This commit comes with some assertions. In
particular, if it appears that on some platform struct data size didn't change
then static assertion will trigger.
Reported-by: Simon Riggs
Discussion: https://postgr.es/m/CANP8%2Bj%2BK4whxf7ET7%2BgO%2BG-baC3-WxqqH%3DnV4X2CgfEPA3Yu3g%40mail.gmail.com
Author: Alexander Korotkov Reviewed-by: Simon Riggs, Alvaro Herrera
Backpatch-through: 9.4
Tom Lane [Sat, 23 Mar 2019 20:24:30 +0000 (16:24 -0400)]
Accept XML documents when xmloption = content, as required by SQL:2006+.
Previously we were using the SQL:2003 definition, which doesn't allow
this, but that creates a serious dump/restore gotcha: there is no
setting of xmloption that will allow all valid XML data. Hence,
switch to the 2006 definition.
Since libxml doesn't accept <!DOCTYPE> directives in the mode we
use for CONTENT parsing, the implementation is to detect <!DOCTYPE>
in the input and switch to DOCUMENT parsing mode. This should not
cost much, because <!DOCTYPE> should be close to the front of the
input if it's there at all. It's possible that this causes the
error messages for malformed input to be slightly different than
they were before, if said input includes <!DOCTYPE>; but that does
not seem like a big problem.
In passing, buy back a few cycles in parsing of large XML documents
by not doing strlen() of the whole input in parse_xml_decl().
Back-patch because dump/restore failures are not nice. This change
shouldn't break any cases that worked before, so it seems safe to
back-patch.
Tom Lane [Tue, 19 Mar 2019 16:49:27 +0000 (12:49 -0400)]
Make checkpoint requests more robust.
Commit 6f6a6d8b1 introduced a delay of up to 2 seconds if we're trying
to request a checkpoint but the checkpointer hasn't started yet (or,
much less likely, our kill() call fails). However buildfarm experience
shows that that's not quite enough for slow or heavily-loaded machines.
There's no good reason to assume that the checkpointer won't start
eventually, so we may as well make the timeout much longer, say 60 sec.
However, if the caller didn't say CHECKPOINT_WAIT, it seems like a bad
idea to be waiting at all, much less for as long as 60 sec. We can
remove the need for that, and make this whole thing more robust, by
adjusting the code so that the existence of a pending checkpoint
request is clear from the contents of shared memory, and making sure
that the checkpointer process will notice it at startup even if it did
not get a signal. In this way there's no need for a non-CHECKPOINT_WAIT
call to wait at all; if it can't send the signal, it can nonetheless
assume that the checkpointer will eventually service the request.
A potential downside of this change is that "kill -INT" on the checkpointer
process is no longer enough to trigger a checkpoint, should anyone be
relying on something so hacky. But there's no obvious reason to do it
like that rather than issuing a plain old CHECKPOINT command, so we'll
assume that nobody is. There doesn't seem to be a way to preserve this
undocumented quasi-feature without introducing race conditions.
Since a principal reason for messing with this is to prevent intermittent
buildfarm failures, back-patch to all supported branches.
Peter Eisentraut [Thu, 14 Mar 2019 07:25:25 +0000 (08:25 +0100)]
Fix volatile vs. pointer confusion
Variables used after a longjmp() need to be declared volatile. In
case of a pointer, it's the pointer itself that needs to be declared
volatile, not the pointed-to value. So we need
Tom Lane [Thu, 14 Mar 2019 16:16:10 +0000 (12:16 -0400)]
Ensure dummy paths have correct required_outer if rel is parameterized.
The assertions added by commits 34ea1ab7f et al found another problem:
set_dummy_rel_pathlist and mark_dummy_rel were failing to label
the dummy paths they create with the correct outer_relids, in case
the relation is necessarily parameterized due to having lateral
references in its tlist. It's likely that this has no user-visible
consequences in production builds, at the moment; but still an assertion
failure is a bad thing, so back-patch the fix.
Per bug #15694 from Roman Zharkov (via Alexander Lakhin)
and an independent report by Tushar Ahuja.
Tom Lane [Sun, 10 Mar 2019 16:58:52 +0000 (12:58 -0400)]
Disallow NaN as a value for floating-point GUCs.
None of the code that uses GUC values is really prepared for them to
hold NaN, but parse_real() didn't have any defense against accepting
such a value. Treat it the same as a syntax error.
I haven't attempted to analyze the exact consequences of setting any
of the float GUCs to NaN, but since they're quite unlikely to be good,
this seems like a back-patchable bug fix.
Note: we don't need an explicit test for +-Infinity because those will
be rejected by existing range checks. I added a regression test for
that in HEAD, but not older branches because the spelling of the value
in the error message will be platform-dependent in branches where we
don't always use port/snprintf.c.
Michael Paquier [Mon, 4 Mar 2019 00:50:19 +0000 (09:50 +0900)]
Fix error handling of readdir() port implementation on first file lookup
The implementation of readdir() in src/port/ which gets used by MSVC has
been added in 399a36a, and since the beginning it considers all errors
on the first file lookup as ENOENT, setting errno accordingly and
letting the routine caller think that the directory is empty. While
this is normally enough for the case of the backend, this can confuse
callers of this routine on Windows as all errors would map to the same
behavior. So, for example, even permission errors would be thought as
having an empty directory, while there could be contents in it.
This commit changes the error handling so as readdir() gets a behavior
similar to native implementations: force errno=0 when seeing
ERROR_FILE_NOT_FOUND as error and consider other errors as plain
failures.
While looking at the patch, I noticed that MinGW does not enforce
errno=0 when looking at the first file, but it gets enforced on the next
file lookups. A comment related to that was incorrect in the code.
Reported-by: Yuri Kurenkov Diagnosed-by: Yuri Kurenkov, Grigory Smolkin
Author: Konstantin Knizhnik Reviewed-by: Andrew Dunstan, Michael Paquier
Discussion: https://postgr.es/m/2cad7829-8d66-e39c-b937-ac825db5203d@postgrespro.ru
Backpatch-through: 9.4
Dean Rasheed [Sun, 3 Mar 2019 10:57:37 +0000 (10:57 +0000)]
Further fixing for multi-row VALUES lists for updatable views.
Previously, rewriteTargetListIU() generated a list of attribute
numbers from the targetlist, which were passed to rewriteValuesRTE(),
which expected them to contain the same number of entries as there are
columns in the VALUES RTE, and to be in the same order. That was fine
when the target relation was a table, but for an updatable view it
could be broken in at least three different ways ---
rewriteTargetListIU() could insert additional targetlist entries for
view columns with defaults, the view columns could be in a different
order from the columns of the underlying base relation, and targetlist
entries could be merged together when assigning to elements of an
array or composite type. As a result, when recursing to the base
relation, the list of attribute numbers generated from the rewritten
targetlist could no longer be relied upon to match the columns of the
VALUES RTE. We got away with that prior to 41531e42d3 because it used
to always be the case that rewriteValuesRTE() did nothing for the
underlying base relation, since all DEFAULTS had already been replaced
when it was initially invoked for the view, but that was incorrect
because it failed to apply defaults from the base relation.
Fix this by examining the targetlist entries more carefully and
picking out just those that are simple Vars referencing the VALUES
RTE. That's sufficient for the purposes of rewriteValuesRTE(), which
is only responsible for dealing with DEFAULT items in the VALUES
RTE. Any DEFAULT item in the VALUES RTE that doesn't have a matching
simple-Var-assignment in the targetlist is an error which we complain
about, but in theory that ought to be impossible.
Additionally, move this code into rewriteValuesRTE() to give a clearer
separation of concerns between the 2 functions. There is no need for
rewriteTargetListIU() to know about the details of the VALUES RTE.
While at it, fix the comment for rewriteValuesRTE() which claimed that
it doesn't support array element and field assignments --- that hasn't
been true since a3c7a993d5 (9.6 and later).
Back-patch to all supported versions, with minor differences for the
pre-9.6 branches, which don't support array element and field
assignments to the same column in multi-row VALUES lists.
Tom Lane [Sun, 24 Feb 2019 17:51:51 +0000 (12:51 -0500)]
Fix ecpg bugs caused by missing semicolons in the backend grammar.
The Bison documentation clearly states that a semicolon is required
after every grammar rule, and our scripts that generate ecpg's
grammar from the backend's implicitly assumed this is true. But it
turns out that only ancient versions of Bison actually enforce that.
There have been a couple of rules without trailing semicolons in
gram.y for some time, and as a consequence, ecpg's grammar was faulty
and produced wrong output for the affected statements.
To fix, add the missing semis, and add some cross-checks to ecpg's
scripts so that they'll bleat if we mess this up again.
The cases that were broken were:
* "SET variable = DEFAULT" (but not "SET variable TO DEFAULT"),
as well as allied syntaxes such as ALTER SYSTEM SET ... DEFAULT.
These produced syntactically invalid output that the server
would reject.
* Multiple type names in DROP TYPE/DOMAIN commands. Only the
first type name would be listed in the emitted command.
Per report from Daisuke Higuchi. Back-patch to all supported versions.
Thomas Munro [Sun, 24 Feb 2019 10:59:26 +0000 (23:59 +1300)]
Tolerate EINVAL when calling fsync() on a directory.
Previously, we tolerated EBADF as a way for the operating system to
indicate that it doesn't support fsync() on a directory. Tolerate
EINVAL too, for older versions of Linux CIFS.
Bug #15636. Back-patch all the way.
Reported-by: John Klann
Discussion: https://postgr.es/m/15636-d380890dafd78fc6@postgresql.org
Tom Lane [Fri, 22 Feb 2019 17:23:00 +0000 (12:23 -0500)]
Fix plan created for inherited UPDATE/DELETE with all tables excluded.
In the case where inheritance_planner() finds that every table has
been excluded by constraints, it thought it could get away with
making a plan consisting of just a dummy Result node. While certainly
there's no updating or deleting to be done, this had two user-visible
problems: the plan did not report the correct set of output columns
when a RETURNING clause was present, and if there were any
statement-level triggers that should be fired, it didn't fire them.
Hence, rather than only generating the dummy Result, we need to
stick a valid ModifyTable node on top, which requires a tad more
effort here.
It's been broken this way for as long as inheritance_planner() has
known about deleting excluded subplans at all (cf commit 635d42e9c),
so back-patch to all supported branches.
Amit Langote and Tom Lane, per a report from Petr Fedorov.
Dean Rasheed [Wed, 20 Feb 2019 08:22:52 +0000 (08:22 +0000)]
Fix DEFAULT-handling in multi-row VALUES lists for updatable views.
INSERT ... VALUES for a single VALUES row is implemented differently
from a multi-row VALUES list, which causes inconsistent behaviour in
the way that DEFAULT items are handled. In particular, when inserting
into an auto-updatable view on top of a table with a column default, a
DEFAULT item in a single VALUES row gets correctly replaced with the
table column's default, but for a multi-row VALUES list it is replaced
with NULL.
Fix this by allowing rewriteValuesRTE() to leave DEFAULT items in the
VALUES list untouched if the target relation is an auto-updatable view
and has no column default, deferring DEFAULT-expansion until the query
against the base relation is rewritten. For all other types of target
relation, including tables and trigger- and rule-updatable views, we
must continue to replace DEFAULT items with NULL in the absence of a
column default.
This is somewhat complicated by the fact that if an auto-updatable
view has DO ALSO rules attached, the VALUES lists for the product
queries need to be handled differently from the original query, since
the product queries need to act like rule-updatable views whereas the
original query has auto-updatable view semantics.
Back-patch to all supported versions.
Reported by Roger Curley (bug #15623). Patch by Amit Langote and me.
Michael Paquier [Wed, 20 Feb 2019 03:32:15 +0000 (12:32 +0900)]
Mark correctly initial slot snapshots with MVCC type when built
When building an initial slot snapshot, snapshots are marked with
historic MVCC snapshots as type with the marker field being set in
SnapBuildBuildSnapshot() but not overriden in SnapBuildExportSnapshot().
Existing callers of SnapBuildBuildSnapshot() do not care about the type
of snapshot used, but extensions calling it actually may, as reported.
Joe Conway [Sun, 17 Feb 2019 18:14:39 +0000 (13:14 -0500)]
Fix documentation for dblink_error_message() return value
The dblink documentation claims that an empty string is returned if there
has been no error, however OK is actually returned in that case. Also,
clarify that an async error may not be seen unless dblink_is_busy() or
dblink_get_result() have been called first.
Tom Lane [Sun, 17 Feb 2019 17:37:32 +0000 (12:37 -0500)]
Fix CREATE VIEW to allow zero-column views.
We should logically have allowed this case when we allowed zero-column
tables, but it was overlooked.
Although this might be thought a feature addition, it's really a bug
fix, because it was possible to create a zero-column view via
the convert-table-to-view code path, and then you'd have a situation
where dump/reload would fail. Hence, back-patch to all supported
branches.
Arrange the added test cases to provide coverage of the related
pg_dump code paths (since these views will be dumped and reloaded
during the pg_upgrade regression test). I also made them test
the case where pg_dump has to postpone the view rule into post-data,
which disturbingly had no regression coverage before.
Report and patch by Ashutosh Sharma (test case by me)
Tatsuo Ishii [Sun, 17 Feb 2019 11:42:58 +0000 (20:42 +0900)]
Doc: remove ancient comment.
There's a very old comment in rules.sgml added back to 2003. It
expected to a feature coming back but it never happened. So now we can
safely remove the comment. Back-patched to all supported branches.
Michael Paquier [Fri, 15 Feb 2019 08:12:51 +0000 (17:12 +0900)]
Fix support for CREATE TABLE IF NOT EXISTS AS EXECUTE
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
Thomas Munro [Thu, 14 Feb 2019 21:19:11 +0000 (10:19 +1300)]
Fix race in dsm_attach() when handles are reused.
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
Alvaro Herrera [Tue, 12 Feb 2019 21:42:37 +0000 (18:42 -0300)]
Relax overly strict assertion
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.
Tom Lane [Tue, 12 Feb 2019 06:12:52 +0000 (01:12 -0500)]
Fix erroneous error reports in snapbuild.c.
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.
Tom Lane [Sun, 10 Feb 2019 02:02:06 +0000 (21:02 -0500)]
Solve cross-version-upgrade testing problem induced by 1fb57af92.
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.
Tom Lane [Sun, 10 Feb 2019 00:45:38 +0000 (19:45 -0500)]
Repair unsafe/unportable snprintf usage in pg_restore.
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.
Tom Lane [Fri, 8 Feb 2019 18:30:42 +0000 (13:30 -0500)]
Defend against null error message reported by libxml2.
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.
Tom Lane [Fri, 8 Feb 2019 17:49:36 +0000 (12:49 -0500)]
Doc: fix thinko in description of how to escape a backslash in bytea.
Also clean up some discussion that had been left in a very confused
state thanks to half-hearted adjustments for the change to
standard_conforming_strings being the default.
Tom Lane [Thu, 7 Feb 2019 18:10:46 +0000 (13:10 -0500)]
Ensure that foreign scans with lateral refs are planned correctly.
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.
Andrew Dunstan [Thu, 7 Feb 2019 15:22:49 +0000 (10:22 -0500)]
Fix searchpath and module location for pg_rewind and ssl TAP tests
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.
Tom Lane [Wed, 6 Feb 2019 17:44:58 +0000 (12:44 -0500)]
Propagate lateral-reference information to indirect descendant relations.
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).
Andrew Dunstan [Wed, 6 Feb 2019 12:32:35 +0000 (07:32 -0500)]
Unify searchpath and do file logic in MSVC build scripts.
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.
Andrew Dunstan [Tue, 5 Feb 2019 23:57:12 +0000 (18:57 -0500)]
Fix included file path for modern perl
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.
Andrew Dunstan [Tue, 5 Feb 2019 23:31:10 +0000 (18:31 -0500)]
More fixed for modern perl on back branches
Use "do" instead of "require" for included files, as it doesn't look for
them in the search path but relative to the current working directory.
These changes have already been made to REL_10_STABLE and later, to
satisfy the demands of perlcritic, but need backporting now to earlier
branches.
Tom Lane [Tue, 5 Feb 2019 15:58:53 +0000 (10:58 -0500)]
Update time zone data files to tzdata release 2018i.
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.
Tom Lane [Tue, 5 Feb 2019 00:18:50 +0000 (19:18 -0500)]
Doc: in each release branch, keep only that branch's own release notes.
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.
Tom Lane [Mon, 4 Feb 2019 22:20:02 +0000 (17:20 -0500)]
Fix dumping of matviews with indirect dependencies on primary keys.
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.
Andrew Gierth [Mon, 4 Feb 2019 18:47:33 +0000 (18:47 +0000)]
Move port-specific parts of with_temp_install to port makefile.
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.)
Michael Paquier [Sun, 3 Feb 2019 08:48:59 +0000 (17:48 +0900)]
Add PG_CFLAGS, PG_CXXFLAGS, and PG_LDFLAGS variables to PGXS
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
Amit Kapila [Sat, 2 Feb 2019 03:46:35 +0000 (09:16 +0530)]
Avoid possible deadlock while locking multiple heap pages.
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
Michael Paquier [Fri, 1 Feb 2019 01:35:58 +0000 (10:35 +0900)]
Fix use of dangling pointer in heap_delete() when logging replica identity
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.
Peter Eisentraut [Mon, 28 Jan 2019 21:09:33 +0000 (22:09 +0100)]
Fix a crash in logical replication
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/
Tom Lane [Sat, 26 Jan 2019 19:15:42 +0000 (14:15 -0500)]
Fix psql's "\g target" meta-command to work with COPY TO STDOUT.
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.
Tom Lane [Sat, 26 Jan 2019 02:14:31 +0000 (21:14 -0500)]
Allow UNLISTEN in hot-standby mode.
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.
Tom Lane [Thu, 24 Jan 2019 21:46:56 +0000 (16:46 -0500)]
Remove infinite-loop hazards in ecpg test suite.
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.
Tom Lane [Thu, 24 Jan 2019 03:46:45 +0000 (22:46 -0500)]
Blind attempt to fix _configthreadlocale() failures on MinGW.
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.
Tom Lane [Tue, 22 Jan 2019 04:18:58 +0000 (23:18 -0500)]
Avoid thread-safety problem in ecpglib.
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.)
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.
Tom Lane [Fri, 18 Jan 2019 20:06:26 +0000 (15:06 -0500)]
Use our own getopt() on OpenBSD.
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.
Andrew Gierth [Thu, 17 Jan 2019 05:33:01 +0000 (05:33 +0000)]
Postpone aggregate checks until after collation is assigned.
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.
Tom Lane [Tue, 8 Jan 2019 17:03:54 +0000 (12:03 -0500)]
Doc: update our docs about kernel IPC parameters on *BSD.
runtime.sgml said that you couldn't change SysV IPC parameters on OpenBSD
except by rebuilding the kernel. That's definitely wrong in OpenBSD 6.x,
and excavation in their man pages says it changed in OpenBSD 3.3.
Update NetBSD and OpenBSD sections to recommend adjustment of the SEMMNI
and SEMMNS settings, which are painfully small by default on those
platforms. (The discussion thread contemplated recommending that
people select POSIX semaphores instead, but the performance consequences
of that aren't really clear, so I'll refrain.)
Remove pointless discussion of SEMMNU and SEMMAP from the FreeBSD
section. Minor other wordsmithing.
Tom Lane [Thu, 3 Jan 2019 22:00:08 +0000 (17:00 -0500)]
Improve ANALYZE's handling of concurrent-update scenarios.
This patch changes the rule for whether or not a tuple seen by ANALYZE
should be included in its sample.
When we last touched this logic, in commit 51e1445f1, we weren't
thinking very hard about tuples being UPDATEd by a long-running
concurrent transaction. In such a case, we might see the pre-image as
either LIVE or DELETE_IN_PROGRESS depending on timing; and we might see
the post-image not at all, or as INSERT_IN_PROGRESS. Since the existing
code will not sample either DELETE_IN_PROGRESS or INSERT_IN_PROGRESS
tuples, this leads to concurrently-updated rows being omitted from the
sample entirely. That's not very helpful, and it's especially the wrong
thing if the concurrent transaction ends up rolling back.
The right thing seems to be to sample DELETE_IN_PROGRESS rows just as if
they were live. This makes the "sample it" and "count it" decisions the
same, which seems good for consistency. It's clearly the right thing
if the concurrent transaction ends up rolling back; in effect, we are
sampling as though IN_PROGRESS transactions haven't happened yet.
Also, this combination of choices ensures maximum robustness against
the different combinations of whether and in which state we might see the
pre- and post-images of an update.
It's slightly annoying that we end up recording immediately-out-of-date
stats in the case where the transaction does commit, but on the other
hand the stats are fine for columns that didn't change in the update.
And the alternative of sampling INSERT_IN_PROGRESS rows instead seems
like a bad idea, because then the sampling would be inconsistent with
the way rows are counted for the stats report.
Per report from Mark Chambers; thanks to Jeff Janes for diagnosing
what was happening. Back-patch to all supported versions.
Debian testing and newer now require that RSA and DHE keys are at
least 2048 bit long and no longer allow SHA-1 for signatures in
certificates. This is currently causing the ssl tests to fail there
because the test certificates and keys have been created in violation
of those conditions.
Update the parameters to create the test files and create a new set of
test files.
Author: Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp> Reported-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://www.postgresql.org/message-id/flat/20180917131340.GE31460%40paquier.xyz
Tom Lane [Wed, 2 Jan 2019 21:33:48 +0000 (16:33 -0500)]
Don't believe MinMaxExpr is leakproof without checking.
MinMaxExpr invokes the btree comparison function for its input datatype,
so it's only leakproof if that function is. Many such functions are
indeed leakproof, but others are not, and we should not just assume that
they are. Hence, adjust contain_leaked_vars to verify the leakproofness
of the referenced function explicitly.
I didn't add a regression test because it would need to depend on
some particular comparison function being leaky, and that's a moving
target, per discussion.
This has been wrong all along, so back-patch to supported branches.
Detect it the way pg_ctl's wait_for_postmaster() does. When pg_regress
spawned a postmaster that failed startup, we were detecting that only
with "pg_regress: postmaster did not respond within 60 seconds".
Back-patch to 9.4 (all supported versions).
Alvaro Herrera [Thu, 27 Dec 2018 19:17:40 +0000 (16:17 -0300)]
Have DISCARD ALL/TEMP remove leftover temp tables
Previously, it would only remove temp tables created in the same
session; but if the session uses the BackendId of a previously crashed
backend that left temp tables around, those would not get removed.
Since autovacuum would not drop them either (because it sees that the
BackendId is in use by the current session) these can cause annoying
xid-wraparound warnings.
Apply to branches 9.4 to 10. This is not a problem since version 11,
because commit 943576bddcb5 added state tracking that makes autovacuum
realize that those temp tables are not ours, so it removes them.
This is useful to handle in DISCARD, because even though it does not
handle all situations, it does handle the common one where a connection
pooler keeps the same session open for an indefinitely long time.
Alvaro Herrera [Thu, 27 Dec 2018 19:00:39 +0000 (16:00 -0300)]
Make autovacuum more selective about temp tables to keep
When temp tables are in danger of XID wraparound, autovacuum drops them;
however, it preserves those that are owned by a working session. This
is desirable, except when the session is connected to a different
database (because the temp tables cannot be from that session), so make
it only keep the temp tables only if the backend is in the same database
as the temp tables.
This is not bulletproof: it fails to detect temp tables left by a
session whose backend ID is reused in the same database but the new
session does not use temp tables. Commit 943576bddcb5 fixes that case
too, for branches 11 and up (which is why we don't apply this fix to
those branches), but back-patching that one is not universally agreed
on.
Michael Paquier [Thu, 27 Dec 2018 01:17:26 +0000 (10:17 +0900)]
Ignore inherited temp relations from other sessions when truncating
Inheritance trees can include temporary tables if the parent is
permanent, which makes possible the presence of multiple temporary
children from different sessions. Trying to issue a TRUNCATE on the
parent in this scenario causes a failure, so similarly to any other
queries just ignore such cases, which makes TRUNCATE work
transparently.
This makes truncation behave similarly to any other DML query working on
the parent table with queries which need to be issues on children. A
set of isolation tests is added to cover basic cases.
Reported-by: Zhou Digoal
Author: Amit Langote, Michael Paquier
Discussion: https://postgr.es/m/15565-ce67a48d0244436a@postgresql.org
Backpatch-through: 9.4
Tom Lane [Wed, 26 Dec 2018 20:30:10 +0000 (15:30 -0500)]
Fix portability failure introduced in commits d2b0b60e7 et al.
I made a frontend fprintf() format use %m, forgetting that that's only
safe in HEAD not the back branches; prior to 96bf88d52 and d6c55de1f,
it would work on glibc platforms but not elsewhere. Revert to using
%s ... strerror(errno) as the code did before.
We could have left HEAD as-is, but for code consistency across branches,
I chose to apply this patch there too.
Michael Paquier [Mon, 24 Dec 2018 11:26:20 +0000 (20:26 +0900)]
Prioritize history files when archiving
At the end of recovery for the post-promotion process, a new history
file is created followed by the last partial segment of the previous
timeline. Based on the timing, the archiver would first try to archive
the last partial segment and then the history file. This can delay the
detection of a new timeline taken, particularly depending on the time it
takes to transfer the last partial segment as it delays the moment the
history file of the new timeline gets archived. This can cause promoted
standbys to use the same timeline as one already taken depending on the
circumstances if multiple instances look at archives at the same
location.
This commit changes the order of archiving so as history files are
archived in priority over other file types, which reduces the likelihood
of the same timeline being taken (still not reducing the window to
zero), and it makes the archiver behave more consistently with the
startup process doing its post-promotion business.
Author: David Steele Reviewed-by: Michael Paquier, Kyotaro Horiguchi
Discussion: https://postgr.es/m/929068cf-69e1-bba2-9dc0-e05986aed471@pgmasters.net
Backpatch-through: 9.5
Tom Lane [Thu, 20 Dec 2018 18:55:11 +0000 (13:55 -0500)]
Doc: fix ancient mistake in search_path documentation.
"$user" in a search_path string is replaced by CURRENT_USER not
SESSION_USER. (It actually was SESSION_USER in the initial implementation,
but we changed it shortly later, and evidently forgot to fix the docs to
match.)
Tom Lane [Tue, 18 Dec 2018 16:19:39 +0000 (11:19 -0500)]
Fix ancient thinko in mergejoin cost estimation.
"rescanratio" was computed as 1 + rescanned-tuples / total-inner-tuples,
which is sensible if it's to be multiplied by total-inner-tuples or a cost
value corresponding to scanning all the inner tuples. But in reality it
was (mostly) multiplied by inner_rows or a related cost, numbers that take
into account the possibility of stopping short of scanning the whole inner
relation thanks to a limited key range in the outer relation. This'd
still make sense if we could expect that stopping short would result in a
proportional decrease in the number of tuples that have to be rescanned.
It does not, however. The argument that establishes the validity of our
estimate for that number is independent of whether we scan all of the inner
relation or stop short, and experimentation also shows that stopping short
doesn't reduce the number of rescanned tuples. So the correct calculation
is 1 + rescanned-tuples / inner_rows, and we should be sure to multiply
that by inner_rows or a corresponding cost value.
Most of the time this doesn't make much difference, but if we have
both a high rescan rate (due to lots of duplicate values) and an outer
key range much smaller than the inner key range, then the error can
be significant, leading to a large underestimate of the cost associated
with rescanning.
Per report from Vijaykumar Jain. This thinko appears to go all the way
back to the introduction of the rescan estimation logic in commit 70fba7043, so back-patch to all supported branches.
Michael Paquier [Mon, 17 Dec 2018 01:36:34 +0000 (10:36 +0900)]
Make constraint rename issue relcache invalidation on target relation
When a constraint gets renamed, it may have associated with it a target
relation (for example domain constraints don't have one). Not
invalidating the target relation cache when issuing the renaming can
result in issues with subsequent commands that refer to the old
constraint name using the relation cache, causing various failures. One
pattern spotted was using CREATE TABLE LIKE after a constraint
renaming.
Reported-by: Stuart <sfbarbee@gmail.com>
Author: Amit Langote Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/2047094.V130LYfLq4@station53.ousa.org
Tom Lane [Sun, 16 Dec 2018 19:51:48 +0000 (14:51 -0500)]
Make error handling in parallel pg_upgrade less bogus.
reap_child() basically ignored the possibility of either an error in
waitpid() itself or a child process failure on signal. We don't really
need to do more than report and crash hard, but proceeding as though
nothing is wrong is definitely Not Acceptable. The error report for
nonzero child exit status was pretty off-point, as well.
Noted while fooling around with child-process failure detection
logic elsewhere. It's been like this a long time, so back-patch to
all supported branches.
Prevent GIN deleted pages from being reclaimed too early
When GIN vacuum deletes a posting tree page, it assumes that no concurrent
searchers can access it, thanks to ginStepRight() locking two pages at once.
However, since 9.4 searches can skip parts of posting trees descending from the
root. That leads to the risk that page is deleted and reclaimed before
concurrent search can access it.
This commit prevents the risk of above by waiting for every transaction, which
might wait to reference this page, to finish. Due to binary compatibility
we can't change GinPageOpaqueData to store corresponding transaction id.
Instead we reuse page header pd_prune_xid field, which is unused in index pages.
Discussion: https://postgr.es/m/31a702a.14dd.166c1366ac1.Coremail.chjischj%40163.com
Author: Andrey Borodin, Alexander Korotkov Reviewed-by: Alexander Korotkov
Backpatch-through: 9.4
On standby ginRedoDeletePage() can work concurrently with read-only queries.
Those queries can traverse posting tree in two ways.
1) Using rightlinks by ginStepRight(), which locks the next page before
unlocking its left sibling.
2) Using downlinks by ginFindLeafPage(), which locks at most one page at time.
Original lock order was: page, parent, left sibling. That lock order can
deadlock with ginStepRight(). In order to prevent deadlock this commit changes
lock order to: left sibling, page, parent. Note, that position of parent in
locking order seems insignificant, because we only lock one page at time while
traversing downlinks.
Reported-by: Chen Huajun Diagnosed-by: Chen Huajun, Peter Geoghegan, Andrey Borodin
Discussion: https://postgr.es/m/31a702a.14dd.166c1366ac1.Coremail.chjischj%40163.com
Author: Alexander Korotkov
Backpatch-through: 9.4
Tom Lane [Wed, 12 Dec 2018 18:49:42 +0000 (13:49 -0500)]
Repair bogus handling of multi-assignment Params in upper plan levels.
Our support for multiple-set-clauses in UPDATE assumes that the Params
referencing a MULTIEXPR_SUBLINK SubPlan will appear before that SubPlan
in the targetlist of the plan node that calculates the updated row.
(Yeah, it's a hack...) In some PG branches it's possible that a Result
node gets inserted between the primary calculation of the update tlist
and the ModifyTable node. setrefs.c did the wrong thing in this case
and left the upper-level Params as Params, causing a crash at runtime.
What it should do is replace them with "outer" Vars referencing the child
plan node's output. That's a result of careless ordering of operations
in fix_upper_expr_mutator, so we can fix it just by reordering the code.
Fix fix_join_expr_mutator similarly for consistency, even though join
nodes could never appear in such a context. (In general, it seems
likely to be a bit cheaper to use Vars than Params in such situations
anyway, so this patch might offer a tiny performance improvement.)
The hazard extends back to 9.5 where the MULTIEXPR_SUBLINK stuff
was introduced, so back-patch that far. However, this may be a live
bug only in 9.6.x and 10.x, as the other branches don't seem to want
to calculate the final tlist below the Result node. (That plan shape
change between branches might be a mini-bug in itself, but I'm not
really interested in digging into the reasons for that right now.
Still, add a regression test memorializing what we expect there,
so we'll notice if it changes again.)
Tom Lane [Tue, 11 Dec 2018 16:48:01 +0000 (11:48 -0500)]
Fix test_rls_hooks to assign expression collations properly.
This module overlooked this necessary fixup step on the results of
transformWhereClause(). It accidentally worked anyway, because the
constructed expression involved type "name" which is not collatable,
but it fell over while I was experimenting with changing "name" to
be collatable.
Back-patch, not because there's any live bug here in back branches,
but because somebody might use this code as a model for some real
application and then not understand why it doesn't work.
Tom Lane [Tue, 11 Dec 2018 16:21:36 +0000 (11:21 -0500)]
Doc: improve documentation about ALTER LARGE OBJECT requirements.
Unlike other ALTER ref pages, this one neglected to mention that
ALTER OWNER requires being a member of the new owning role.
Per bug #15546 from Stefan Kadow.
projects / postgresql / log