Tom Lane [Tue, 16 May 2017 19:24:52 +0000 (15:24 -0400)]
Try to ensure that stats collector's receive buffer size is at least 100KB.
Since commit 4e37b3e15, buildfarm member frogmouth has been failing
occasionally with symptoms indicating that some expected stats data is
getting dropped. The reason that that commit changed the behavior seems
probably to be that more data is getting shoved at the collector in a short
span of time. In current sources, the stats test's first session sends
about 9KB of data while exiting, which is probably the same as what was
sent just before wait_for_stats() in the previous test design. But now,
the test's second session is starting up concurrently, and it sends another
2KB (presumably reflecting its initial catalog accesses). Since frogmouth
is running on Windows XP, which reputedly has a default socket receive
buffer size of only 8KB, it is not very surprising if this has put us over
the threshold where the receive buffer can overflow and drop messages.
The same mechanism could very easily explain the intermittent stats test
failures we've been seeing for years, since background processes such
as the bgwriter will sometimes send data concurrently with all this, and
could thus cause occasional buffer overflows.
Hence, insert some code into pgstat_init() to increase the stats socket's
receive buffer size to 100KB if it's less than that. (On failure, emit a
LOG message, but keep going.) Modern systems seem to have default sizes
in the range of 100KB-250KB, but older platforms don't. I couldn't find
any platforms that wouldn't accept 100KB, so in theory this won't cause
any portability problems.
If this is successful at reducing the buildfarm failure rate in HEAD,
we should back-patch it, because it's certain that similar buffer overflows
happen in the field on platforms with small buffer sizes. Going forward,
there might be an argument for trying to increase the buffer size even
more, but let's take a baby step first.
Tom Lane [Tue, 16 May 2017 03:27:51 +0000 (23:27 -0400)]
In SSL tests, don't scribble on permissions of a repo file.
Modifying the permissions of a persistent file isn't really much nicer
than modifying its contents, even if git doesn't currently notice it.
Adjust the test script to make a copy and set the permissions of that
instead.
Michael Paquier, per a gripe from me. Back-patch to 9.5 where these
tests were introduced.
Tom Lane [Mon, 15 May 2017 15:33:44 +0000 (11:33 -0400)]
Fix unsafe reference into relcache in constructed CommentStmt.
The CommentStmt made by RebuildConstraintComment() has to pstrdup the
relation name, else it will contain a dangling pointer after that
relcache entry is flushed. (I'm less sure that pstrdup'ing conname
is necessary, but let's be safe.) Failure to do this leads to weird
errors or crashes, as reported by Marko Elezovic.
Bug introduced by commit e42375fc8, so back-patch to 9.5 as that was.
Fix by David Rowley, regression test by Michael Paquier
Peter Eisentraut [Wed, 10 May 2017 03:35:31 +0000 (23:35 -0400)]
Fix ALTER SEQUENCE locking
In 1753b1b027035029c2a2a1649065762fafbf63f3, the pg_sequence system
catalog was introduced. This made sequence metadata changes
transactional, while the actual sequence values are still behaving
nontransactionally. This requires some refinement in how ALTER
SEQUENCE, which operates on both, locks the sequence and the catalog.
The main problems were:
- Concurrent ALTER SEQUENCE causes "tuple concurrently updated" error,
caused by updates to pg_sequence catalog.
- Sequence WAL writes and catalog updates are not protected by same
lock, which could lead to inconsistent recovery order.
- nextval() disregarding uncommitted ALTER SEQUENCE changes.
To fix, nextval() and friends now lock the sequence using
RowExclusiveLock instead of AccessShareLock. ALTER SEQUENCE locks the
sequence using ShareRowExclusiveLock. This means that nextval() and
ALTER SEQUENCE block each other, and ALTER SEQUENCE on the same sequence
blocks itself. (This was already the case previously for the OWNER TO,
RENAME, and SET SCHEMA variants.) Also, rearrange some code so that the
entire AlterSequence is protected by the lock on the sequence.
As an exception, use reduced locking for ALTER SEQUENCE ... RESTART.
Since that is basically a setval(), it does not require the full locking
of other ALTER SEQUENCE actions. So check whether we are only running a
RESTART and run with less locking if so.
Reviewed-by: Michael Paquier <michael.paquier@gmail.com> Reported-by: Jason Petersen <jason@citusdata.com> Reported-by: Andres Freund <andres@anarazel.de>
Tom Lane [Mon, 15 May 2017 03:33:03 +0000 (23:33 -0400)]
stats regression test's wait_for_stats() must check timestamp too.
pg_stat_get_snapshot_timestamp() returns the timestamp seen in the "global"
stats file. Because pgstat_write_statsfiles() writes per-DB stats files
before the global file (or at least before renaming it into place), there
is a window where the test backend can see all the stats updates that
wait_for_stats() was checking for (all of which come from the per-DB file)
but also see the same global stats file it had seen at the start of the
test script. This results in a failure in only the "snapshot_newer" query,
as reported by a couple of buildfarm members recently.
I suspect that this ought to be back-patched. Commit 4e37b3e15 has
evidently increased the probability of this window getting hit, but
it's not apparent why it could not have been hit before. I'll refrain
for the moment though.
Fix cases where an elog(ERROR) partway through a function would leave the
persistent data structures in a corrupt state. pgstat_report_stat got this
wrong by invalidating PgStat_TableEntry structs before removing hashtable
entries pointing to them, and get_tabstat_entry got it wrong by ignoring
the possibility of palloc failure after it had already created a hashtable
entry.
Also, avoid leaking a memory context per transaction, which the previous
code did through misunderstanding hash_create's API. We do not need to
create a context to hold the hash table; hash_create will do that.
(The leak wasn't that large, amounting to only a memory context header
per iteration, but it's still surprising that nobody noticed it yet.)
Tom Lane [Mon, 15 May 2017 01:39:10 +0000 (21:39 -0400)]
Make stats regression test more robust in the face of parallel query.
Commit 60690a6fe attempted to fix the wait_for_stats() function in this
test so that it would wait properly if the tenk2 scans were done in
parallel workers instead of the main session (typically as a consequence of
force_parallel_mode being turned on). However, we made it test for whether
the main session's actions had been reported by looking for inserts on
'trunc_stats_test'. This is the Wrong Thing, because those aren't the last
updates we expect the main session to do. As shown by recent failures on
buildfarm member frogmouth, it's entirely likely that the trunc_stats_test
updates will be reported in a separate message from later updates, which
means there can be a window in which wait_for_stats() will exit but not all
the updates we are expecting to see will have arrived. We should test for
the last updates we're expecting, namely those on 'trunc_stats_test4'.
Unfortunately, I doubt that this explains frogmouth's failures, because
there's no reason to believe that it's running the tenk2 queries in
parallel. Still, the test is wrong on its own terms, so fix and back-patch
to 9.6 where parallel query came in.
Robert Haas [Mon, 15 May 2017 00:59:28 +0000 (20:59 -0400)]
Attempt to fix compiler warning.
Per a report from Tom Lane, newer versions of gcc apparently think
that partexprs_item_saved can be used uninitialized. Try to convince
them otherwise.
Tom Lane [Sun, 14 May 2017 17:32:59 +0000 (13:32 -0400)]
Fix maintenance hazards caused by ill-considered use of default: cases.
Remove default cases from assorted switches over ObjectClass and some
related enum types, so that we'll get compiler warnings when someone
adds a new enum value without accounting for it in all these places.
In passing, re-order some switch cases as needed to match the declaration
of enum ObjectClass. OK, that's just neatnik-ism, but I dislike code
that looks like it was assembled with the help of a dartboard.
Tom Lane [Sun, 14 May 2017 16:22:16 +0000 (12:22 -0400)]
Fix handling of extended statistics during ALTER COLUMN TYPE.
ALTER COLUMN TYPE on a column used by a statistics object fails since
commit 928c4de30, because the relevant switch in ATExecAlterColumnType
is unprepared for columns to have dependencies from OCLASS_STATISTIC_EXT
objects.
Although the existing types of extended statistics don't actually need us
to do any work for a column type change, it seems completely indefensible
that that assumption is hidden behind the failure of an unrelated module
to contain any code for the case. Hence, create and call an API function
in statscmds.c where the assumption can be explained, and where we could
add code to deal with the problem when it inevitably becomes real.
Also, the reason this wasn't handled before, neither for extended stats
nor for the last half-dozen new OCLASS kinds :-(, is that the default:
in that switch suppresses compiler warnings, allowing people to miss the
need to consider it when adding an OCLASS. We don't really need a default
because surely getObjectClass should only return valid values of the enum;
so remove it, and add the missed OCLASS entries where they should be.
Tom Lane [Sun, 14 May 2017 14:54:47 +0000 (10:54 -0400)]
Standardize terminology for pg_statistic_ext entries.
Consistently refer to such an entry as a "statistics object", not just
"statistics" or "extended statistics". Previously we had a mismash of
terms, accompanied by utter confusion as to whether the term was
singular or plural. That's not only grating (at least to the ear of
a native English speaker) but could be outright misleading, eg in error
messages that seemed to be referring to multiple objects where only one
could be meant.
This commit fixes the code and a lot of comments (though I may have
missed a few). I also renamed two new SQL functions,
pg_get_statisticsextdef -> pg_get_statisticsobjdef
pg_statistic_ext_is_visible -> pg_statistics_obj_is_visible
to conform better with this terminology.
I have not touched the SGML docs other than fixing those function
names; the docs certainly need work but it seems like a separable task.
Andrew Dunstan [Sun, 14 May 2017 05:10:18 +0000 (01:10 -0400)]
Suppress indentation from Data::Dumper in regression tests
Ultra-modern versions of the perl Data::Dumper module have apparently
changed how they indent output. Instead of trying to keep up we choose
to tell it to supporess all indentation in the hstore_plperl regression
tests.
Backpatch to 9.5 where this feature was introduced.
Andres Freund [Sat, 13 May 2017 21:47:41 +0000 (14:47 -0700)]
Avoid superfluous work for commits during logical slot creation.
Before 955a684e0401 logical decoding snapshot maintenance needed to
cope with transactions it might not have seen in their entirety. For
such transactions we'd to assume they modified the catalog (could have
happened before we were watching), and thus a new snapshot had to be
built, and distributed to concurrently running transactions.
That's problematic because building a new snapshot isn't that cheap ,
especially as the the array of committed transactions needs to be
sorted. When creating a slot on a server with a lot of transactions,
this could make logical slot creation infeasibly expensive.
After 955a684e0401 there's no need to deal with transaction that
aren't guaranteed to be fully observable. That allows to avoid
building snapshots for transactions that haven't modified catalog,
even before reaching consistency.
While this isn't necessarily a bugfix, slot creation being impossible
in some production workloads, is severe enough to warrant
backpatching.
Author: Andres Freund, based on a quite different patch from Petr Jelinek Analyzed-By: Petr Jelinek Reviewed-By: Petr Jelinek
Discussion: https://postgr.es/m/f37e975c-908f-858e-707f-058d3b1eb214@2ndquadrant.com
Backpatch: 9.4-, where logical decoding has been introduced
Andres Freund [Sat, 13 May 2017 21:21:00 +0000 (14:21 -0700)]
Fix race condition leading to hanging logical slot creation.
The snapshot assembly during the creation of logical slots relied
waiting for transactions in xl_running_xacts to end, by checking for
their commit/abort records. Unfortunately, despite locking, it is
possible to see an xl_running_xact record listing transactions as
ready, that have already WAL-logged an commit/abort record, as the
locking just prevents the ProcArray to be adjusted, and the commit
record has to be logged first.
That lead to either delayed or hanging snapshot creation, because
snapbuild.c would wait "forever" to see commit/abort records for some
transactions. That hang resolved only if a xl_running_xacts record
without any running transactions happened to be logged, far from
certain on a busy server.
It's impractical to prevent that via more heavyweight locking, the
likelihood of deadlocks and significantly increased contention would
be too big.
Instead change the initial snapshot creation to be solely based on
tracking the oldest running transaction via
xl_running_xacts->oldestRunningXid - that actually ends up
significantly simplifying the code. That has two disadvantages:
1) Because we cannot fully "trust" the contents of xl_running_xacts,
we cannot use it to build the initial snapshot. Instead we have to
wait twice for all running transactions to finish.
2) Previously a slot, unless the race occurred, could be created when
the all transaction perceived as running based on commit/abort
records, now we have to wait for the next xl_running_xacts record.
To address that, trigger logging new xl_running_xacts record from
within snapbuild.c exactly when necessary.
Unfortunately snabuild.c's SnapBuild is stored on disk, one of the
stupider ideas of a certain Mr Freund, so we can't change it in a
minor release. As this is going to be backpatched, we have to hack
around a bit to keep on-disk compatibility. A later commit will
rejigger that on master.
Author: Andres Freund, based on a quite different patch from Petr Jelinek Analyzed-By: Petr Jelinek Reviewed-By: Petr Jelinek
Discussion: https://postgr.es/m/f37e975c-908f-858e-707f-058d3b1eb214@2ndquadrant.com
Backpatch: 9.4-, where logical decoding has been introduced
Tom Lane [Sat, 13 May 2017 19:14:39 +0000 (15:14 -0400)]
Redesign get_attstatsslot()/free_attstatsslot() for more safety and speed.
The mess cleaned up in commit da0759600 is clear evidence that it's a
bug hazard to expect the caller of get_attstatsslot()/free_attstatsslot()
to provide the correct type OID for the array elements in the slot.
Moreover, we weren't even getting any performance benefit from that,
since get_attstatsslot() was extracting the real type OID from the array
anyway. So we ought to get rid of that requirement; indeed, it would
make more sense for get_attstatsslot() to pass back the type OID it found,
in case the caller isn't sure what to expect, which is likely in binary-
compatible-operator cases.
Another problem with the current implementation is that if the stats array
element type is pass-by-reference, we incur a palloc/memcpy/pfree cycle
for each element. That seemed acceptable when the code was written because
we were targeting O(10) array sizes --- but these days, stats arrays are
almost always bigger than that, sometimes much bigger. We can save a
significant number of cycles by doing one palloc/memcpy/pfree of the whole
array. Indeed, in the now-probably-common case where the array is toasted,
that happens anyway so this method is basically free. (Note: although the
catcache code will inline any out-of-line toasted values, it doesn't
decompress them. At the other end of the size range, it doesn't expand
short-header datums either. In either case, DatumGetArrayTypeP would have
to make a copy. We do end up using an extra array copy step if the element
type is pass-by-value and the array length is neither small enough for a
short header nor large enough to have suffered compression. But that
seems like a very acceptable price for winning in pass-by-ref cases.)
Hence, redesign to take these insights into account. While at it,
convert to an API in which we fill a struct rather than passing a bunch
of pointers to individual output arguments. That will make it less
painful if we ever want further expansion of what get_attstatsslot can
pass back.
It's certainly arguable that this is new development and not something to
push post-feature-freeze. However, I view it as primarily bug-proofing
and therefore something that's better to have sooner not later. Since
we aren't quite at beta phase yet, let's put it in.
Tom Lane [Sat, 13 May 2017 13:42:12 +0000 (09:42 -0400)]
Avoid hard-wired sleep delays in stats regression test.
On faster machines, the overall runtime for running the core regression
tests is under twenty seconds these days, of which the hard-wired delays
in the stats test are a significant fraction. But on closer inspection,
it seems like we shouldn't need those.
The initial 2-second delay is there only to reduce the risk of the test's
stats messages not getting sent due to contention. But analysis of the
last ten years' worth of buildfarm runs shows no evidence that such
failures actually occur. (We do see failures that look like stats
messages not getting sent, particularly on Windows; but there is little
reason to believe that the initial delay reduces their frequency.)
The later 1-second delay is there to ensure that our session's stats
will have gotten sent. But we could also do that by starting a fresh
session, which takes well under 1 second even on very slow machines.
Hence, let's remove both delays and see what happens. The first delay
was the only test of pg_sleep_for() in the regression tests, but we can
move that responsibility into wait_for_stats().
Alvaro Herrera [Sat, 13 May 2017 04:05:48 +0000 (01:05 -0300)]
Complete tab completion for DROP STATISTICS
Tab-completing DROP STATISTICS would only work if you started writing
the schema name containing the statistics object, because the visibility
clause was missing. To add it, we need to add SQL-callable support for
testing visibility of a statistics object, like all other object types
already have.
Tom Lane [Fri, 12 May 2017 23:05:13 +0000 (19:05 -0400)]
Avoid searching for callback functions in CallSyscacheCallbacks().
We have now grown enough registerable syscache-invalidation callback
functions that the original assumption that there would be few of them
is causing performance problems. In particular, let's fix things so that
CallSyscacheCallbacks doesn't have to search the whole array to find
which callback(s) to invoke for a given cache ID. Preserve the original
behavior that callbacks are called in order of registration, just in
case there's someplace that depends on that (which I doubt).
In support of this, export the number of syscaches from syscache.h.
People could have found that out anyway from the enum, but adding a
#define makes that much safer.
This provides a useful additional speedup in Mathieu Fenniak's
logical-decoding test case, although we're reaching the point of
diminishing returns there. I think any further improvement will have
to come from reducing the number of cache invalidations that are
triggered in the first place. Still, we can hope that this change
gives some incremental benefit for all invalidation scenarios.
Back-patch to 9.4 where logical decoding was introduced.
Tom Lane [Fri, 12 May 2017 22:30:02 +0000 (18:30 -0400)]
Reduce initial size of RelfilenodeMapHash.
A test case provided by Mathieu Fenniak shows that hash_seq_search'ing
this hashtable can consume a very significant amount of overhead during
logical decoding, which triggers frequent cache invalidation. Testing
suggests that the actual population of the hashtable is often no more
than a few dozen entries, so we can cut the overhead just by dropping
the initial number of buckets down from 1024 --- I chose to cut it to 64.
(In situations where we do have a significant number of entries, we
shouldn't get any real penalty from doing this, as the dynahash.c code
will resize the hashtable automatically.)
This gives a further factor-of-two savings in Mathieu's test case.
That may be overly optimistic for real-world benefit, as real cases
may have larger average table populations, but it's hard to see it
turning into a net negative for any workload.
Back-patch to 9.4 where relfilenodemap.c was introduced.
Remove the "default:" clause in the switch, to avoid this problem in the
future. Other switches involving the same enum should probably be
changed in the same way, but are not touched by this patch.
Tom Lane [Fri, 12 May 2017 22:17:29 +0000 (18:17 -0400)]
Avoid searching for the target catcache in CatalogCacheIdInvalidate.
A test case provided by Mathieu Fenniak shows that the initial search for
the target catcache in CatalogCacheIdInvalidate consumes a very significant
amount of overhead in cases where cache invalidation is triggered but has
little useful work to do. There is no good reason for that search to exist
at all, as the index array maintained by syscache.c allows direct lookup of
the catcache from its ID. We just need a frontend function in syscache.c,
matching the division of labor for most other cache-accessing operations.
While there's more that can be done in this area, this patch alone reduces
the runtime of Mathieu's example by 2X. We can hope that it offers some
useful benefit in other cases too, although usually cache invalidation
overhead is not such a striking fraction of the total runtime.
Back-patch to 9.4 where logical decoding was introduced. It might be
worth going further back, but presently the only case we know of where
cache invalidation is really a significant burden is in logical decoding.
Also, older branches have fewer catcaches, reducing the possible benefit.
(Note: although this nominally changes catcache's API, we have always
documented CatalogCacheIdInvalidate as a private function, so I would
have little sympathy for an external module calling it directly. So
backpatching should be fine.)
Tom Lane [Fri, 12 May 2017 20:26:31 +0000 (16:26 -0400)]
Fix dependencies for extended statistics objects.
A stats object ought to have a dependency on each individual column
it reads, not the entire table. Doing this honestly lets us get rid
of the hard-wired logic in RemoveStatisticsExt, which seems to have
been misguidedly modeled on RemoveStatistics; and it will be far easier
to extend to multiple tables later.
Also, add overlooked dependency on owner, and make the dependency on
schema be NORMAL like every other such dependency.
There remains some unfinished work here, which is to allow statistics
objects to be extension members. That takes more effort than just
adding the dependency call, though, so I left it out for now.
initdb forced because this changes the set of pg_depend records that
should exist for a statistics object.
Alvaro Herrera [Fri, 12 May 2017 17:59:23 +0000 (14:59 -0300)]
Change CREATE STATISTICS syntax
Previously, we had the WITH clause in the middle of the command, where
you'd specify both generic options as well as statistic types. Few
people liked this, so this commit changes it to remove the WITH keyword
from that clause and makes it accept statistic types only. (We
currently don't have any generic options, but if we invent in the
future, we will gain a new WITH clause, probably at the end of the
command).
Also, the column list is now specified without parens, which makes the
whole command look more similar to a SELECT command. This change will
let us expand the command to supporting expressions (not just columns
names) as well as multiple tables and their join conditions.
Tom added lots of code comments and fixed some parts of the CREATE
STATISTICS reference page, too; more changes in this area are
forthcoming. He also fixed a potential problem in the alter_generic
regression test, reducing verbosity on a cascaded drop to avoid
dependency on message ordering, as we do in other tests.
Tom also closed a security bug: we documented that table ownership was
required in order to create a statistics object on it, but didn't
actually implement it.
Implement tab-completion for statistics objects. This can stand some
more improvement.
Authors: Alvaro Herrera, with lots of cleanup by Tom Lane
Discussion: https://postgr.es/m/20170420212426.ltvgyhnefvhixm6i@alvherre.pgsql
Andrew Dunstan [Fri, 12 May 2017 15:11:49 +0000 (11:11 -0400)]
Honor PROVE_FLAGS environment setting
On MSVC builds and on back branches that means removing the hardcoded
--verbose setting. On master for Unix that means removing the empty
setting in the global Makefile so that the value can be acquired from
the environment as well as from the make arguments.
Andrew Dunstan [Fri, 12 May 2017 14:17:54 +0000 (10:17 -0400)]
Add libxml2 include path for MSVC builds
On Unix this path is detected via the use of xml2-config, but that's not
available on Windows. This means that users building with libxml2 will
no longer need to move things around from the standard libxml2
installation for MSVC builds.
Andrew Dunstan [Fri, 12 May 2017 10:41:23 +0000 (06:41 -0400)]
Avoid tests which crash the calling process on Windows
Certain recovery tests use the Perl IPC::Run module's start/kill_kill
method of processing. On at least some versions of perl this causes the
whole process and its caller to crash. If we ever find a better way of
doing these tests they can be re-enabled on this platform. This does not
affect Mingw or Cygwin builds, which use a different perl and a
different shell and so are not affected.
Tom Lane [Thu, 11 May 2017 18:51:21 +0000 (14:51 -0400)]
Increase MAX_SYSCACHE_CALLBACKS to provide more room for extensions.
Increase from the historical value of 32 to 64. We are up to 31 callers
of CacheRegisterSyscacheCallback() in HEAD, so if they were all to be
exercised in one process that would leave only one slot for add-on modules.
It's probably not possible for that to happen, but still we clearly need
more daylight here. (At some point it might be worth making the array
dynamically resizable; but since we've never heard a complaint of "out of
syscache_callback_list slots" happening in the field, I doubt it's worth
it yet.)
Back-patch as far as 9.4, which is where we increased the companion limit
MAX_RELCACHE_CALLBACKS (cf commit f01d1ae3a). It's not as urgent in
released branches, which have only a couple dozen call sites in core, but
it still seems that somebody might hit the limit before these branches die.
Tom Lane [Thu, 11 May 2017 15:49:59 +0000 (11:49 -0400)]
Rename WAL-related functions and views to use "lsn" not "location".
Per discussion, "location" is a rather vague term that could refer to
multiple concepts. "LSN" is an unambiguous term for WAL locations and
should be preferred. Some function names, view column names, and function
output argument names used "lsn" already, but others used "location",
as well as yet other terms such as "wal_position". Since we've already
renamed a lot of things in this area from "xlog" to "wal" for v10,
we may as well incur a bit more compatibility pain and make these names
all consistent.
While the functionality that was intended to be provided by these
commits is desired, the patch didn't actually solve as many of the
problematic situations as we hoped, and it created a bunch of its own
problems. Since we're going to require more extensive changes soon for
other reasons and users have been working around these problems for a
long time already, there is no point in spending effort in fixing this
halfway measure.
Per complaint from Tom Lane.
Discussion: https://postgr.es/m/21407.1484606922@sss.pgh.pa.us
(Commit fa2fa9955280 had already been reverted in branches 9.5 as f858524ee4f and 9.6 as e9e44a0953, so this touches master only.
Commit 42f50cb8fa98 was not present in the older branches.)
Robert Haas [Wed, 10 May 2017 03:44:21 +0000 (23:44 -0400)]
Remove no-longer-needed compatibility code for hash indexes.
Because commit ea69a0dead5128c421140dc53fac165ba4af8520 bumped the
HASH_VERSION, we don't need to worry about PostgreSQL 10 seeing
bucket pages from earlier versions.
Robert Haas [Wed, 10 May 2017 03:34:02 +0000 (23:34 -0400)]
Prohibit transition tables on views and foreign tables.
Thomas Munro, per off-list report from Prabhat Sabu. Changes
to the message wording for consistency with the existing
relkind check for partitioned tables by me.
Previously, the memory used by the logical replication apply worker for
processing messages would never be freed, so that could end up using a
lot of memory. To improve that, change the existing ApplyContext memory
context to ApplyMessageContext and reset that after every
message (similar to MessageContext used elsewhere). For consistency of
naming, rename the ApplyCacheContext to ApplyContext.
Remove the NODROP SLOT option from DROP SUBSCRIPTION
It turned out this approach had problems, because a DROP command should
not have any options other than CASCADE and RESTRICT. Instead, always
attempt to drop the slot if there is one configured, but also add an
ALTER SUBSCRIPTION action to set the slot to NONE.
Author: Petr Jelinek <petr.jelinek@2ndquadrant.com> Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/29431.1493730652@sss.pgh.pa.us
Tom Lane [Mon, 8 May 2017 19:02:57 +0000 (15:02 -0400)]
Further patch rangetypes_selfuncs.c's statistics slot management.
Values in a STATISTIC_KIND_RANGE_LENGTH_HISTOGRAM slot are float8,
not of the type of the column the statistics are for.
This bug is at least partly the fault of sloppy specification comments
for get_attstatsslot()/free_attstatsslot(): the type OID they want is that
of the stavalues entries, not of the underlying column. (I double-checked
other callers and they seem to get this right.) Adjust the comments to be
more correct.
Fix statistics reporting in logical replication workers
This new arrangement ensures that statistics are reported right after
commit of transactions. The previous arrangement didn't get this quite
right and could lead to assertion failures.
Author: Petr Jelinek <petr.jelinek@2ndquadrant.com> Reported-by: Erik Rijkers <er@xs4all.nl>
Noah Misch [Mon, 8 May 2017 14:24:24 +0000 (07:24 -0700)]
Match pg_user_mappings limits to information_schema.user_mapping_options.
Both views replace the umoptions field with NULL when the user does not
meet qualifications to see it. They used different qualifications, and
pg_user_mappings documented qualifications did not match its implemented
qualifications. Make its documentation and implementation match those
of user_mapping_options. One might argue for stronger qualifications,
but these have long, documented tenure. pg_user_mappings has always
exhibited this problem, so back-patch to 9.2 (all supported versions).
Michael Paquier and Feike Steenbergen. Reviewed by Jeff Janes.
Reported by Andrew Wheelwright.
Noah Misch [Mon, 8 May 2017 14:24:24 +0000 (07:24 -0700)]
Restore PGREQUIRESSL recognition in libpq.
Commit 65c3bf19fd3e1f6a591618e92eb4c54d0b217564 moved handling of the,
already then, deprecated requiressl parameter into conninfo_storeval().
The default PGREQUIRESSL environment variable was however lost in the
change resulting in a potentially silent accept of a non-SSL connection
even when set. Its documentation remained. Restore its implementation.
Also amend the documentation to mark PGREQUIRESSL as deprecated for
those not following the link to requiressl. Back-patch to 9.3, where
commit 65c3bf1 first appeared.
Behavior has been more complex when the user provides both deprecated
and non-deprecated settings. Before commit 65c3bf1, libpq operated
according to the first of these found:
requiressl=1
PGREQUIRESSL=1
sslmode=*
PGSSLMODE=*
(Note requiressl=0 didn't override sslmode=*; it would only suppress
PGREQUIRESSL=1 or a previous requiressl=1. PGREQUIRESSL=0 had no effect
whatsoever.) Starting with commit 65c3bf1, libpq ignored PGREQUIRESSL,
and order of precedence changed to this:
last of requiressl=* or sslmode=*
PGSSLMODE=*
Starting now, adopt the following order of precedence:
last of requiressl=* or sslmode=*
PGSSLMODE=*
PGREQUIRESSL=1
This retains the 65c3bf1 behavior for connection strings that contain
both requiressl=* and sslmode=*. It retains the 65c3bf1 change that
either connection string option overrides both environment variables.
For the first time, PGSSLMODE has precedence over PGREQUIRESSL; this
avoids reducing security of "PGREQUIRESSL=1 PGSSLMODE=verify-full"
configurations originating under v9.3 and later.
Add security checks to selectivity estimation functions
Some selectivity estimation functions run user-supplied operators over
data obtained from pg_statistic without security checks, which allows
those operators to leak pg_statistic data without having privileges on
the underlying tables. Fix by checking that one of the following is
satisfied: (1) the user has table or column privileges on the table
underlying the pg_statistic data, or (2) the function implementing the
user-supplied operator is leak-proof. If neither is satisfied, planning
will proceed as if there are no statistics available.
At least one of these is satisfied in most cases in practice. The only
situations that are negatively impacted are user-defined or
not-leak-proof operators on a security-barrier view.
Reported-by: Robert Haas <robertmhaas@gmail.com>
Author: Peter Eisentraut <peter_e@gmx.net>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Remove support for password_encryption='off' / 'plain'.
Storing passwords in plaintext hasn't been a good idea for a very long
time, if ever. Now seems like a good time to finally forbid it, since we're
messing with this in PostgreSQL 10 anyway.
Remove the CREATE/ALTER USER UNENCRYPTED PASSSWORD 'foo' syntax, since
storing passwords unencrypted is no longer supported. ENCRYPTED PASSWORD
'foo' is still accepted, but ENCRYPTED is now just a noise-word, it does
the same as just PASSWORD 'foo'.
Likewise, remove the --unencrypted option from createuser, but accept
--encrypted as a no-op for backward compatibility. AFAICS, --encrypted was
a no-op even before this patch, because createuser encrypted the password
before sending it to the server even if --encrypted was not specified. It
added the ENCRYPTED keyword to the SQL command, but since the password was
already in encrypted form, it didn't make any difference. The documentation
was not clear on whether that was intended or not, but it's moot now.
Also, while password_encryption='on' is still accepted as an alias for
'md5', it is now marked as hidden, so that it is not listed as an accepted
value in error hints, for example. That's not directly related to removing
'plain', but it seems better this way.
Tom Lane [Sun, 7 May 2017 18:43:04 +0000 (14:43 -0400)]
Third pass on 9.6.3 release notes.
Add updates for recent commits.
In passing, credit Etsuro Fujita for his work on the postgres_fdw
query cancel feature in 9.6; I seem to have missed that in the
original drafting of the 9.6 notes.
Tom Lane [Sun, 7 May 2017 16:33:12 +0000 (12:33 -0400)]
Guard against null t->tm_zone in strftime.c.
The upstream IANA code does not guard against null TM_ZONE pointers in this
function, but in our code there is such a check in the other pre-existing
use of t->tm_zone. We do have some places that set pg_tm.tm_zone to NULL.
I'm not entirely sure it's possible to reach strftime with such a value,
but I'm not sure it isn't either, so be safe.
Tom Lane [Sun, 7 May 2017 15:57:41 +0000 (11:57 -0400)]
Install the "posixrules" timezone link in MSVC builds.
Somehow, we'd missed ever doing this. The consequences aren't too
severe: basically, the timezone library would fall back on its hardwired
notion of the DST transition dates to use for a POSIX-style zone name,
rather than obeying US/Eastern which is the intended behavior. The net
effect would only be to obey current US DST law further back than it
ought to apply; so it's not real surprising that nobody noticed.
Tom Lane [Sun, 7 May 2017 15:34:31 +0000 (11:34 -0400)]
Restore fullname[] contents before falling through in pg_open_tzfile().
Fix oversight in commit af2c5aa88: if the shortcut open() doesn't work,
we need to reset fullname[] to be just the name of the toplevel tzdata
directory before we fall through into the pre-existing code. This failed
to be exposed in my (tgl's) testing because the fall-through path is
actually never taken under normal circumstances.
Stephen Frost [Sun, 7 May 2017 02:58:12 +0000 (22:58 -0400)]
pg_dump: Don't leak memory in buildDefaultACLCommands()
buildDefaultACLCommands() didn't destroy the string buffer created in
certain cases, leading to a memory leak. Fix by destroying the buffer
before returning from the function.
Spotted by Coverity.
Author: Michael Paquier
Back-patch to 9.6 where buildDefaultACLCommands() was added.
Stephen Frost [Sun, 7 May 2017 01:46:35 +0000 (21:46 -0400)]
RLS: Fix ALL vs. SELECT+UPDATE policy usage
When we add the SELECT-privilege based policies to the RLS with check
options (such as for an UPDATE statement, or when we have INSERT ...
RETURNING), we need to be sure and use the 'USING' case if the policy is
actually an 'ALL' policy (which could have both a USING clause and an
independent WITH CHECK clause).
This could result in policies acting differently when built using ALL
(when the ALL had both USING and WITH CHECK clauses) and when building
the policies independently as SELECT and UPDATE policies.
Fix this by adding an explicit boolean to add_with_check_options() to
indicate when the USING policy should be used, even if the policy has
both USING and WITH CHECK policies on it.
Andres Freund [Sun, 7 May 2017 00:03:04 +0000 (17:03 -0700)]
Fix duplicated words in comment.
Reported-By: Peter Geoghegan
Discussion: https://postgr.es/m/CAH2-Wzn3rY2N0gTWndaApD113T+O8L6oz8cm7_F3P8y4awdoOg@mail.gmail.com
Backpatch: no, only present in master
Andres Freund [Sat, 6 May 2017 23:47:40 +0000 (16:47 -0700)]
Fix off-by-one possibly leading to skipped XLOG_RUNNING_XACTS records.
Since 6ef2eba3f57f1 ("Skip checkpoints, archiving on idle systems."),
GetLastImportantRecPtr() is used to avoid performing superfluous
checkpoints, xlog switches, running-xact records when the system is
idle. Unfortunately the check concerning running-xact records had a
off-by-one error, leading to such records being potentially skipped
when only a single record has been inserted since the last
running-xact record.
An alternative approach would have been to change
GetLastImportantRecPtr()'s definition to point to the end of records,
but that would make the checkpoint code more complicated.
Author: Andres Freund
Discussion: https://postgr.es/m/20170505012447.wsrympaxnfis6ojt@alap3.anarazel.de
Backpatch: no, code only present in master
Tom Lane [Sat, 6 May 2017 20:28:20 +0000 (16:28 -0400)]
Second pass on 9.6.3 release notes.
Improve description of logical decoding snapshot issues, per suggestion
from Petr Jelinek. Mention possible need to re-sync logical replicas
as a post-upgrade task. Minor copy-editing for some other items.
Tom Lane [Fri, 5 May 2017 23:33:34 +0000 (19:33 -0400)]
First-draft release notes for 9.6.3.
As usual, the release notes for other branches will be made by cutting
these down, but put them up for community review first. Note there
are some entries that really only apply to pre-9.6 branches.
projects / postgresql / log