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44458 Commits

Author SHA1 Message Date
Peter Eisentraut
2bac1d8c98 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/
2019-01-30 10:58:28 +01:00
Magnus Hagander
11b6345281 Improve wording about WAL files in tar mode of pg_basebackup
Author: Alex Kliukin
Reviewed-By: Michael Paquier, Magnus Hagander
2019-01-29 10:44:29 +01:00
Tom Lane
8e97a97b32 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.

Daniel Vérité, reviewed by Fabien Coelho

Discussion: https://postgr.es/m/15dadc39-e050-4d46-956b-dcc4ed098753@manitou-mail.org
2019-01-26 14:15:42 -05:00
Tom Lane
e8ec19cd13 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.

Shay Rojansky, reviewed by Mi Tar

Discussion: https://postgr.es/m/CADT4RqCf2gA_TJtPAjnGzkC3ZiexfBZiLmA-mV66e4UyuVv8bA@mail.gmail.com
2019-01-25 21:14:31 -05:00
Tom Lane
5b5cb3b0eb 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.

Discussion: https://postgr.es/m/18693.1548302004@sss.pgh.pa.us
2019-01-24 16:46:55 -05:00
Tom Lane
dd815a94cc 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.

Discussion: https://postgr.es/m/d06a16bc-52d6-9f0d-2379-21242d7dbe81@2ndQuadrant.com
2019-01-23 22:47:03 -05:00
Heikki Linnakangas
2146718b3c Fix misc typos in comments.
Spotted mostly by Fabien Coelho.

Discussion: https://www.postgresql.org/message-id/alpine.DEB.2.21.1901230947050.16643@lancre
2019-01-23 13:50:50 +02:00
Tom Lane
6106f9dd71 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.)

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
2019-01-21 23:18:58 -05:00
Tom Lane
5aa03f99fe Remove useless bms_copy step in RelationGetIndexAttrBitmap.
Seems to be from a bad case of copy-and-paste-itis in commit 665d1fad9.
It wouldn't be quite so annoying if it didn't contradict the comment
half a dozen lines above.

David Rowley

Discussion: https://postgr.es/m/CAKJS1f95Dyf8Qkdz4W+PbCmT-HTb54tkqUCC8isa2RVgSJ_pXQ@mail.gmail.com
2019-01-21 18:33:44 -05:00
Alvaro Herrera
3037b28b89 Flush relcache entries when their FKs are meddled with
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
2019-01-21 19:34:11 -03:00
Alvaro Herrera
c2f557d4fa Add 'id' to Acknowledgments section
Per note from Erik Rijkers
Discussion: https://postgr.es/m/3db724af16ee009ab7f812a6a1d9354e@xs4all.nl
2019-01-21 14:41:51 -03:00
Tomas Vondra
6831aba29f Revert "Add valgrind suppressions for wcsrtombs optimizations"
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
2019-01-19 20:45:31 +01:00
Peter Eisentraut
7cfd1dd031 Fix outdated comment
The issue the comment is referring to was fixed by
08859bb5c2cebc132629ca838113d27bb31b990c.
2019-01-19 09:36:36 +01:00
Tom Lane
139e427426 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.

Discussion: https://postgr.es/m/30197.1547835700@sss.pgh.pa.us
2019-01-18 15:06:26 -05:00
Michael Paquier
08b53281f4 Enforce non-parallel plan when calling current_schema() in newly-added test
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
2019-01-18 10:51:52 +09:00
Michael Paquier
b15160bc71 Restrict the use of temporary namespace in two-phase transactions
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
2019-01-18 09:21:58 +09:00
Magnus Hagander
729c6c3f92 Replace references to mailinglists with @lists.postgresql.org
The namespace for all lists have changed a while ago, so all references
should use the correct address.
2019-01-17 13:52:51 +01:00
Magnus Hagander
d6e8899359 Remove references to Majordomo
Lists are not handled by Majordomo anymore and haven't been for
a while, so remove the reference and instead direct people to the
list server.
2019-01-17 13:47:24 +01:00
Andrew Gierth
409230a721 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.

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
2019-01-17 06:25:55 +00:00
Michael Paquier
3607dd39ba Fix typos in documentation and for one wait event
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
2019-01-15 08:47:14 +09:00
Andrew Dunstan
b3a5f01b75 fix typo 2019-01-13 16:44:05 -05:00
Andrew Dunstan
d68d670027 Make DLSUFFIX easily discoverable by build scripts
This will enable things like the buildfarm client to discover more
reliably if certain libraries have been installed.

Discussion: https://postgr.es/m/859e7c91-7ef4-d4b4-2ca2-8046e0cbee09@2ndQuadrant.com

Backpatch to all live branches.
2019-01-13 16:04:57 -05:00
Peter Eisentraut
cd1873160d configure: Update python search order
Some systems don't ship with "python" by default anymore, only
"python3" or "python2" or some combination, so include those in the
configure search.

Discussion: https://www.postgresql.org/message-id/flat/1457.1543184081%40sss.pgh.pa.us#c9cc1199338fd6a257589c6dcea6cf8d
2019-01-13 10:25:23 +01:00
Tom Lane
10ab85254d Fix up confusion over how to use EXTRA_INSTALL.
Some makefiles were trying to do this:

temp-install: EXTRA_INSTALL=contrib/test_decoding

but that no longer works as of commit aa019da52: the macro is now
consulted by the checkprep target, one level down, and apparently
gmake doesn't propagate such macro settings recursively.

The problem is masked since 42e61c774 because pgxs.mk also sets up
EXTRA_INSTALL, and correctly applies it to the checkprep target.

Unfortunately I'd not risked back-patching that to before v11.
Since aa019da52 was pushed back to v10, it broke test_decoding
there (the only module for which this actually makes a difference
at present).

Hence, back-patch 42e61c774 to v10.  Also, remove some demonstrably
useless settings of EXTRA_INSTALL in v10 and v11 (they'd already
been cleaned up in HEAD).

Per buildfarm.

Discussion: https://postgr.es/m/CAEepm=1pEJdwv6DSGmOfpX0EaX7L7sT28c1nXpqvQvmLfEWb1g@mail.gmail.com
2019-01-11 17:39:30 -05:00
Tom Lane
2977a312df Avoid sharing PARAM_EXEC slots between different levels of NestLoop.
Up to now, createplan.c attempted to share PARAM_EXEC slots for
NestLoopParams across different plan levels, if the same underlying Var
was being fed down to different righthand-side subplan trees by different
NestLoops.  This was, I think, more of an artifact of using subselect.c's
PlannerParamItem infrastructure than an explicit design goal, but anyway
that was the end result.

This works well enough as long as the plan tree is executing synchronously,
but the feature whereby Gather can execute the parallelized subplan locally
breaks it.  An upper NestLoop node might execute for a row retrieved from
a parallel worker, and assign a value for a PARAM_EXEC slot from that row,
while the leader's copy of the parallelized subplan is suspended with a
different active value of the row the Var comes from.  When control
eventually returns to the leader's subplan, it gets the wrong answers if
the same PARAM_EXEC slot is being used within the subplan, as reported
in bug #15577 from Bartosz Polnik.

This is pretty reminiscent of the problem fixed in commit 46c508fbc, and
the proper fix seems to be the same: don't try to share PARAM_EXEC slots
across different levels of controlling NestLoop nodes.

This requires decoupling NestLoopParam handling from PlannerParamItem
handling, although the logic remains somewhat similar.  To avoid bizarre
division of labor between subselect.c and createplan.c, I decided to move
all the param-slot-assignment logic for both cases out of those files
and put it into a new file paramassign.c.  Hopefully it's a bit better
documented now, too.

A regression test case for this might be nice, but we don't know a
test case that triggers the problem with a suitably small amount
of data.

Back-patch to 9.6 where we added Gather nodes.  It's conceivable that
related problems exist in older branches; but without some evidence
for that, I'll leave the older branches alone.

Discussion: https://postgr.es/m/15577-ca61ab18904af852@postgresql.org
2019-01-11 15:54:09 -05:00
Peter Eisentraut
cbb3e08467 doc: Correct documentation of install-time environment variables
Since approximately PostgreSQL 10, it is no longer required that
environment variables at installation time such as PERL, PYTHON, TCLSH
be "full path names", so change that phrasing in the installation
instructions.  (The exact time of change appears to differ for PERL
and the others, but it works consistently in PostgreSQL 10.)

Also while we're here document the defaults for PERL and PYTHON, but
since the search list for TCLSH is so long, let's leave that out so we
don't need to maintain a copy of that list in the installation
instructions.
2019-01-11 17:27:21 +01:00
Tom Lane
f3ff9cb0a3 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.

Discussion: https://postgr.es/m/27582.1546928073@sss.pgh.pa.us
2019-01-08 12:03:54 -05:00
Andrew Gierth
dd4143d065 doc: document that INFO messages always go to client.
In passing add a couple of links to the message severity table.

Backpatch because it's always been this way.

Author: Karl O. Pinc <kop@meme.com>
2019-01-07 18:58:30 +00:00
Tom Lane
708931c2d2 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.

Discussion: https://postgr.es/m/CAFh58O_Myr6G3tcH3gcGrF-=OExB08PJdWZcSBcEcovaiPsrHA@mail.gmail.com
2019-01-03 17:00:08 -05:00
Peter Eisentraut
114635e552 Update ssl test certificates and keys
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
2019-01-03 15:07:54 +01:00
Tom Lane
64edc788b4 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.

Discussion: https://postgr.es/m/31042.1546194242@sss.pgh.pa.us
2019-01-02 16:33:48 -05:00
Bruce Momjian
afd090a00d Update copyright for 2019
Backpatch-through: certain files through 9.4
2019-01-02 12:44:25 -05:00
Michael Paquier
962da60591 Fix generation of padding message before encrypting Elgamal in pgcrypto
fe0a0b5, which has added a stronger random source in Postgres, has
introduced a thinko when creating a padding message which gets encrypted
for Elgamal.  The padding message cannot have zeros, which are replaced
by random bytes.  However if pg_strong_random() failed, the message
would finish by being considered in correct shape for encryption with
zeros.

Author: Tom Lane
Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/20186.1546188423@sss.pgh.pa.us
Backpatch-through: 10
2019-01-01 10:39:34 +09:00
Noah Misch
bedda9fbb7 Process EXTRA_INSTALL serially, during the first temp-install.
This closes a race condition in "make -j check-world"; the symptom was
EEXIST errors.  Back-patch to v10, before which parallel check-world had
worse problems.

Discussion: https://postgr.es/m/20181224221601.GA3227827@rfd.leadboat.com
2018-12-31 13:57:57 -08:00
Noah Misch
e7ebc8c285 Send EXTRA_INSTALL errors to install.log, not stderr.
We already redirected other temp-install stderr and all temp-install
stdout in this way.  Back-patch to v10, like the next commit.

Discussion: https://postgr.es/m/20181224221601.GA3227827@rfd.leadboat.com
2018-12-31 13:55:04 -08:00
Noah Misch
7c97b0f55e pg_regress: Promptly detect failed postmaster startup.
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).

Reviewed by Tom Lane.

Discussion: https://postgr.es/m/20181231172922.GA199150@gust.leadboat.com
2018-12-31 13:51:18 -08:00
Peter Eisentraut
af99ad191a pg_rewind: Add missing newline to error message 2018-12-29 13:03:22 +01:00
Tom Lane
f256995e33 Fix latent problem with pg_jrand48().
POSIX specifies that jrand48() returns a signed 32-bit value (in the
range [-2^31, 2^31)), but our code was returning an unsigned 32-bit
value (in the range [0, 2^32)).  This doesn't actually matter to any
existing call site, because they all cast the "long" result to int32
or uint32; but it will doubtless bite somebody in the future.
To fix, cast the arithmetic result to int32 explicitly before the
compiler widens it to long (if widening is needed).

While at it, upgrade this file's far-short-of-project-style comments.
Had there been some peer pressure to document pg_jrand48() properly,
maybe this thinko wouldn't have gotten committed to begin with.

Backpatch to v10 where pg_jrand48() was added, just in case somebody
back-patches a fix that uses it and depends on the standard behavior.

Discussion: https://postgr.es/m/17235.1545951602@sss.pgh.pa.us
2018-12-28 14:08:35 -05:00
Alvaro Herrera
3c4ca21093 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.

Discussion: https://postgr.es/m/20181226190834.wsk2wzott5yzrjiq@alvherre.pgsql
Reviewed-by: Takayuki Tsunakawa, Michaël Paquier
2018-12-27 16:17:40 -03:00
Alvaro Herrera
a6ca47cd2f 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.

Discussion: https://postgr.es/m/20181214162843.37g6h3txto43akrb@alvherre.pgsql
Reviewed-by: Takayuki Tsunakawa, Michaël Paquier
2018-12-27 16:00:39 -03:00
Michael Paquier
d4486700b5 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
2018-12-27 10:17:13 +09:00
Tom Lane
9939ea16c2 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.

Per Coverity and a few buildfarm members.
2018-12-26 15:30:27 -05:00
Michael Paquier
0857575774 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
2018-12-24 20:25:57 +09:00
Michael Paquier
15f69279e0 Disable WAL-skipping optimization for COPY on views
COPY can skip writing WAL when loading data on a table which has been
created in the same transaction as the one loading the data, however
this cannot work on views as this would result in trying to flush
relation files which do not exist.  So disable the optimization so as
commands are able to work the same way with any configuration of
wal_level.

A test is added to cover this case, which needs to have wal_level set to
minimal to allow the problem to show up, and that is not the default
configuration.

Reported-by: Etsuro Fujita
Author: Michael Paquier
Reviewed-by: Etsuro Fujita
Discussion: https://postgr.es/m/15552-c64aa14c5c22f63c@postgresql.org
Backpatch-through: 10, where support for COPY on views has been added,
while v11 has added support for COPY on foreign tables.
2018-12-23 16:43:56 +09:00
Peter Eisentraut
669d9eae85 Fix ancient compiler warnings and typos in !HAVE_SYMLINK code
This has never been correct since this code was introduced.
2018-12-22 07:25:43 +01:00
Alexander Korotkov
e36e25275f Check for conflicting queries during replay of gistvacuumpage()
013ebc0a7b implements so-called GiST microvacuum.  That is gistgettuple() marks
index tuples as dead when kill_prior_tuple is set.  Later, when new tuple
insertion claims page space, those dead index tuples are physically deleted
from page.  When this deletion is replayed on standby, it might conflict with
read-only queries.  But 013ebc0a7b doesn't handle this.  That may lead to
disappearance of some tuples from read-only snapshots on standby.

This commit implements resolving of conflicts between replay of GiST microvacuum
and standby queries.  On the master we implement new WAL record type
XLOG_GIST_DELETE, which comprises necessary information.  On stable releases
we've to be tricky to keep WAL compatibility.  Information required for conflict
processing is just appended to data of XLOG_GIST_PAGE_UPDATE record.  So,
PostgreSQL version, which doesn't know about conflict processing, will just
ignore that.

Reported-by: Andres Freund
Diagnosed-by: Andres Freund
Discussion: https://postgr.es/m/20181212224524.scafnlyjindmrbe6%40alap3.anarazel.de
Author: Alexander Korotkov
Backpatch-through: 9.6
2018-12-21 02:33:48 +03:00
Alvaro Herrera
1c142612c8 Fix lock level used for partition when detaching it
For probably bogus reasons, we acquire only AccessShareLock on the
partition when we try to detach it from its parent partitioned table.
This can cause ugly things to happen if another transaction is doing
any sort of DDL to the partition concurrently.

Upgrade that lock to ShareUpdateExclusiveLock, which per discussion
seems to be the minimum needed.

Reported by Robert Haas.

Discussion: https://postgr.es/m/CA+TgmoYruJQ+2qnFLtF1xQtr71pdwgfxy3Ziy-TxV28M6pEmyA@mail.gmail.com
2018-12-20 16:42:13 -03:00
Tom Lane
164d439550 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.)

Noted by antonov@stdpr.ru

Discussion: https://postgr.es/m/159151fb45d490c8d31ea9707e9ba99d@stdpr.ru
2018-12-20 13:55:11 -05:00
Greg Stark
9e6cd794c2 Fix ADD IF NOT EXISTS used in conjunction with ALTER TABLE ONLY
The flag for IF NOT EXISTS was only being passed down in the normal
recursing case. It's been this way since originally added in 9.6 in
commit 2cd40adb85 so backpatch back to 9.6.
2018-12-19 19:41:06 -05:00
Tom Lane
4aad9813e8 Doc: fix incorrect example of collecting arguments with fmgr macros.
Thinko in commit f66912b0a.  Back-patch to v10, as that was.

Discussion: https://postgr.es/m/154522283371.15419.15167411691473730460@wrigleys.postgresql.org
2018-12-19 11:02:08 -05:00