Tom Lane [Fri, 29 Jul 2016 23:31:06 +0000 (19:31 -0400)]
Fix worst memory leaks in tqueue.c.
TupleQueueReaderNext() leaks like a sieve if it has to do any tuple
disassembly/reconstruction. While we could try to clean up its allocations
piecemeal, it seems like a better idea just to insist that it should be run
in a short-lived memory context, so that any transient space goes away
automatically. I chose to have nodeGather.c switch into its existing
per-tuple context before the call, rather than inventing a separate
context inside tqueue.c.
This is sufficient to stop all leakage in the simple case I exhibited
earlier today (see link below), but it does not deal with leaks induced
in more complex cases by tqueue.c's insistence on using TopMemoryContext
for data that it's not actually trying hard to keep track of. That issue
is intertwined with another major source of inefficiency, namely failure
to cache lookup results across calls, so it seems best to deal with it
separately.
In passing, improve some comments, and modify gather_readnext's method for
deciding when it's visited all the readers so that it's more obviously
correct. (I'm not actually convinced that the previous code *is*
correct in the case of a reader deletion; it certainly seems fragile.)
Tom Lane [Fri, 29 Jul 2016 16:52:57 +0000 (12:52 -0400)]
Fix pq_putmessage_noblock() to not block.
An evident copy-and-pasteo in commit 2bd9e412f broke the non-blocking
aspect of pq_putmessage_noblock(), causing it to behave identically to
pq_putmessage(). That function is nowadays used only in walsender.c,
so that the net effect was to cause walsenders to hang up waiting for
the receiver in situations where they should not.
Tom Lane [Thu, 28 Jul 2016 22:57:24 +0000 (18:57 -0400)]
Guard against empty buffer in gets_fromFile()'s check for a newline.
Per the fgets() specification, it cannot return without reading some data
unless it reports EOF or error. So the code here assumed that the data
buffer would necessarily be nonempty when we go to check for a newline
having been read. However, Agostino Sarubbo noticed that this could fail
to be true if the first byte of the data is a NUL (\0). The fgets() API
doesn't really work for embedded NULs, which is something I don't feel
any great need for us to worry about since we generally don't allow NULs
in SQL strings anyway. But we should not access off the end of our own
buffer if the case occurs. Normally this would just be a harmless read,
but if you were unlucky the byte before the buffer would contain '\n'
and we'd overwrite it with '\0', and if you were really unlucky that
might be valuable data and psql would crash.
Agostino reported this to pgsql-security, but after discussion we concluded
that it isn't worth treating as a security bug; if you can control the
input to psql you can do far more interesting things than just maybe-crash
it. Nonetheless, it is a bug, so back-patch to all supported versions.
Tom Lane [Thu, 28 Jul 2016 21:23:03 +0000 (17:23 -0400)]
Teach parser to transform "x IS [NOT] DISTINCT FROM NULL" to a NullTest.
Now that we've nailed down the principle that NullTest with !argisrow
is fully equivalent to SQL's IS [NOT] DISTINCT FROM NULL, let's teach
the parser about it. This produces a slightly more compact parse tree
and is much more amenable to optimization than a DistinctExpr, since
the planner knows a good deal about NullTest and next to nothing about
DistinctExpr.
I'm not sure that there are all that many queries in the wild that could
be improved by this, but at least one source of such cases is the patch
just made to postgres_fdw to emit IS [NOT] DISTINCT FROM NULL when
IS [NOT] NULL isn't semantically correct.
No back-patch, since to the extent that this does affect planning results,
it might be considered undesirable plan destabilization.
Tom Lane [Thu, 28 Jul 2016 20:09:15 +0000 (16:09 -0400)]
Fix assorted fallout from IS [NOT] NULL patch.
Commits 4452000f3 et al established semantics for NullTest.argisrow that
are a bit different from its initial conception: rather than being merely
a cache of whether we've determined the input to have composite type,
the flag now has the further meaning that we should apply field-by-field
testing as per the standard's definition of IS [NOT] NULL. If argisrow
is false and yet the input has composite type, the construct instead has
the semantics of IS [NOT] DISTINCT FROM NULL. Update the comments in
primnodes.h to clarify this, and fix ruleutils.c and deparse.c to print
such cases correctly. In the case of ruleutils.c, this merely results in
cosmetic changes in EXPLAIN output, since the case can't currently arise
in stored rules. However, it represents a live bug for deparse.c, which
would formerly have sent a remote query that had semantics different
from the local behavior. (From the user's standpoint, this means that
testing a remote nested-composite column for null-ness could have had
unexpected recursive behavior much like that fixed in 4452000f3.)
In a related but somewhat independent fix, make plancat.c set argisrow
to false in all NullTest expressions constructed to represent "attnotnull"
constructs. Since attnotnull is actually enforced as a simple null-value
check, this is a more accurate representation of the semantics; we were
previously overpromising what it meant for composite columns, which might
possibly lead to incorrect planner optimizations. (It seems that what the
SQL spec expects a NOT NULL constraint to mean is an IS NOT NULL test, so
arguably we are violating the spec and should fix attnotnull to do the
other thing. If we ever do, this part should get reverted.)
Tom Lane [Thu, 28 Jul 2016 17:26:58 +0000 (13:26 -0400)]
Improve documentation about CREATE TABLE ... LIKE.
The docs failed to explain that LIKE INCLUDING INDEXES would not preserve
the names of indexes and associated constraints. Also, it wasn't mentioned
that EXCLUDE constraints would be copied by this option. The latter
oversight seems enough of a documentation bug to justify back-patching.
In passing, do some minor copy-editing in the same area, and add an entry
for LIKE under "Compatibility", since it's not exactly a faithful
implementation of the standard's feature.
Tom Lane [Thu, 28 Jul 2016 15:39:10 +0000 (11:39 -0400)]
Register atexit hook only once in pg_upgrade.
start_postmaster() registered stop_postmaster_atexit as an atexit(3)
callback each time through, although the obvious intention was to do
so only once per program run. The extra registrations were harmless,
so long as we didn't exceed ATEXIT_MAX, but still it's a bug.
Artur Zakirov, with bikeshedding by Kyotaro Horiguchi and me
Tom Lane [Thu, 28 Jul 2016 06:08:52 +0000 (02:08 -0400)]
tqueue.c's record-typmod hashtables need the HASH_BLOBS option.
The keys are integers, not strings. The code accidentally worked on
little-endian machines, at least up to 256 distinct record types within
a session, but failed utterly on big-endian. This was unexpectedly
exposed by a test case added by commit 4452000f3, which apparently is the
only parallelizable query in the regression suite that uses more than one
anonymous record type. Fortunately, buildfarm member mandrill is
big-endian and is running with force_parallel_mode on, so it failed.
Tom Lane [Wed, 27 Jul 2016 21:44:34 +0000 (17:44 -0400)]
Fix cost_rescan() to account for multi-batch hashing correctly.
cost_rescan assumed that we don't need to rebuild the hash table when
rescanning a hash join. However, that's currently only true for
single-batch joins; for a multi-batch join we must charge full freight.
This probably has escaped notice because we'd be unlikely to put a hash
join on the inside of a nestloop anyway. Nonetheless, it's wrong.
Fix in HEAD, but don't backpatch for fear of destabilizing plans in
stable releases.
Tom Lane [Wed, 27 Jul 2016 01:33:49 +0000 (21:33 -0400)]
Allow functions that return sets of tuples to return simple NULLs.
ExecMakeTableFunctionResult(), which is used in SELECT FROM function(...)
cases, formerly treated a simple NULL output from a function that both
returnsSet and returnsTuple as a violation of the SRF protocol. What seems
better is to treat a NULL output as equivalent to ROW(NULL,NULL,...).
Without this, cases such as SELECT FROM unnest(...) on an array of
composite are vulnerable to unexpected and not-very-helpful failures.
Old code comments here suggested an alternative of just ignoring
simple-NULL outputs, but that doesn't seem very principled.
This change had been hung up for a long time due to uncertainty about
how much we wanted to buy into the equivalence of simple NULL and
ROW(NULL,NULL,...). I think that's been mostly resolved by the discussion
around bug #14235, so let's go ahead and do it.
Per bug #7808 from Joe Van Dyk. Although this is a pretty old report,
fixing it smells a bit more like a new feature than a bug fix, and the
lack of other similar complaints suggests that we shouldn't take much risk
of destabilization by back-patching. (Maybe that could be revisited once
this patch has withstood some field usage.)
Robert Haas [Tue, 26 Jul 2016 20:07:02 +0000 (16:07 -0400)]
Change various deparsing functions to return NULL for invalid input.
Previously, some functions returned various fixed strings and others
failed with a cache lookup error. Per discussion, standardize on
returning NULL. Although user-exposed "cache lookup failed" error
messages might normally qualify for bug-fix treatment, no back-patch;
the risk of breaking user code which is accustomed to the current
behavior seems too high.
Robert Haas [Tue, 26 Jul 2016 19:32:57 +0000 (15:32 -0400)]
Repair damage done by citext--1.1--1.2.sql.
That script is incorrect in that it sets the combine function for
max(citext) twice instead of setting the combine function for
max(citext) once and the combine functon for min(citext) once. The
consequence is that if you install 1.0 or 1.1 and then update to 1.2,
you end up with min(citext) not having a combine function, contrary to
what was intended. If you install 1.2 directly, you're OK.
Fix things up by defining a new 1.3 version. Upgrading from 1.2 to
1.3 won't change anything for people who first installed the 1.2
version, but people upgrading from 1.0 or 1.1 will get the right
catalog contents once they reach 1.3.
Report and patch by David Rowley, reviewed by Andreas Karlsson.
Tom Lane [Tue, 26 Jul 2016 19:25:02 +0000 (15:25 -0400)]
Fix constant-folding of ROW(...) IS [NOT] NULL with composite fields.
The SQL standard appears to specify that IS [NOT] NULL's tests of field
nullness are non-recursive, ie, we shouldn't consider that a composite
field with value ROW(NULL,NULL) is null for this purpose.
ExecEvalNullTest got this right, but eval_const_expressions did not,
leading to weird inconsistencies depending on whether the expression
was such that the planner could apply constant folding.
Also, adjust the docs to mention that IS [NOT] DISTINCT FROM NULL can be
used as a substitute test if a simple null check is wanted for a rowtype
argument. That motivated reordering things so that IS [NOT] DISTINCT FROM
is described before IS [NOT] NULL. In HEAD, I went a bit further and added
a table showing all the comparison-related predicates.
Per bug #14235. Back-patch to all supported branches, since it's certainly
undesirable that constant-folding should change the semantics.
Report and patch by Andrew Gierth; assorted wordsmithing and revised
regression test cases by me.
Fix improper example of using psql() function in TAP tests documentation.
In an example of TAP test scripts, there is the test checking whether
the result of the query is expected or not. But, in previous example,
the exit code of psql instead of the query result was checked unexpectedly.
These tests are currently only running in buildfarm member hamster,
which is purposefully very slow. This suite has failed a couple of
times recently because of timeouts, so increase the allowed number of
iterations to avoid spurious failures.
Tom Lane [Sun, 24 Jul 2016 00:16:48 +0000 (20:16 -0400)]
Correctly set up aggregate FILTER expression in partial-aggregation plans.
The aggfilter expression should be removed from the parent (combining)
Aggref, since it's not supposed to apply the filter, and indeed cannot
because any Vars used in the filter would not be available after the
lower-level aggregation step. Per report from Jeff Janes.
(This has been broken since the introduction of partial aggregation,
I think. The error became obvious after commit 59a3795c2, when setrefs.c
began processing the parent Aggref's fields normally and thus would detect
such Vars. The special-case coding previously used in setrefs.c skipped
over the parent's aggfilter field without processing it. That was broken
in its own way because no other setrefs.c processing got applied either;
though since the executor would not execute the filter expression, only
initialize it, that oversight might not have had any visible symptoms at
present.)
Tom Lane [Fri, 22 Jul 2016 19:41:39 +0000 (15:41 -0400)]
Fix regression tests to work in Welsh locale.
Welsh (cy_GB) apparently sorts 'dd' after 'f', creating problems
analogous to the odd sorting of 'aa' in Danish. Adjust regression
test case to not use data that provokes that.
Tom Lane [Fri, 22 Jul 2016 15:32:23 +0000 (11:32 -0400)]
Remove GetUserMappingId() and GetUserMappingById().
These functions were added in commits fbe5a3fb7 and a104a017f,
but commit 45639a052 removed their only callers. Put the related
code in foreign.c back to the way it was in 9.5, to avoid pointless
cross-version diffs.
Tom Lane [Thu, 21 Jul 2016 20:52:35 +0000 (16:52 -0400)]
Make contrib regression tests safe for Danish locale.
In btree_gin and citext, avoid some not-particularly-interesting
dependencies on the sorting of 'aa'. In tsearch2, use COLLATE "C" to
remove an uninteresting dependency on locale sort order (and thereby
allow removal of a variant expected-file).
Also, in citext, avoid assuming that lower('I') = 'i'. This isn't relevant
to Danish but it does fail in Turkish.
Tom Lane [Thu, 21 Jul 2016 18:24:07 +0000 (14:24 -0400)]
Make pltcl regression tests safe for Danish locale.
Another peculiarity of Danish locale is that it has an unusual idea
of how to sort upper vs. lower case. One of the pltcl test cases has
an issue with that. Now that COLLATE works in all supported branches,
we can just change the test to be locale-independent, and get rid of
the variant expected file that used to support non-C locales.
Tom Lane [Thu, 21 Jul 2016 17:11:00 +0000 (13:11 -0400)]
Make core regression tests safe for Danish locale.
Some tests added in 9.5 depended on 'aa' sorting before 'bb', which
doesn't hold true in Danish. Use slightly different test data to
avoid the problem.
Tom Lane [Tue, 19 Jul 2016 22:41:30 +0000 (18:41 -0400)]
Remove very-obsolete estimates of shmem usage from postgresql.conf.sample.
runtime.sgml used to contain a table of estimated shared memory consumption
rates for max_connections and some other GUCs. Commit 390bfc643 removed
that on the well-founded grounds that (a) we weren't maintaining the
entries well and (b) it no longer mattered so much once we got out from
under SysV shmem limits. But it missed that there were even-more-obsolete
versions of some of those numbers in comments in postgresql.conf.sample.
Remove those too. Back-patch to 9.3 where the aforesaid commit went in.
Tom Lane [Mon, 18 Jul 2016 20:52:06 +0000 (16:52 -0400)]
Doc: improve discussion of plpgsql's GET DIAGNOSTICS, other minor fixes.
9.4 added a second description of GET DIAGNOSTICS that was totally
independent of the existing one, resulting in each description lying to the
extent that it claimed the set of status items it described was complete.
Fix that, and do some minor markup improvement.
Also some other small fixes per bug #14258 from Dilian Palauzov.
Andres Freund [Mon, 18 Jul 2016 09:01:13 +0000 (02:01 -0700)]
Clear all-frozen visibilitymap status when locking tuples.
Since a892234 & fd31cd265 the visibilitymap's freeze bit is used to
avoid vacuuming the whole relation in anti-wraparound vacuums. Doing so
correctly relies on not adding xids to the heap without also unsetting
the visibilitymap flag. Tuple locking related code has not done so.
To allow selectively resetting all-frozen - to avoid pessimizing
heap_lock_tuple - allow to selectively reset the all-frozen with
visibilitymap_clear(). To avoid having to use
visibilitymap_get_status (e.g. via VM_ALL_FROZEN) inside a critical
section, have visibilitymap_clear() return whether any bits have been
reset.
There's a remaining issue (denoted by XXX): After the PageIsAllVisible()
check in heap_lock_tuple() and heap_lock_updated_tuple_rec() the page
status could theoretically change. Practically that currently seems
impossible, because updaters will hold a page level pin already. Due to
the next beta coming up, it seems better to get the required WAL magic
bump done before resolving this issue.
The added flags field fields to xl_heap_lock and xl_heap_lock_updated
require bumping the WAL magic. Since there's already been a catversion
bump since the last beta, that's not an issue.
Reviewed-By: Robert Haas, Amit Kapila and Andres Freund
Author: Masahiko Sawada, heavily revised by Andres Freund
Discussion: CAEepm=3fWAbWryVW9swHyLTY4sXVf0xbLvXqOwUoDiNCx9mBjQ@mail.gmail.com
Backpatch: -
Tom Lane [Sun, 17 Jul 2016 22:42:31 +0000 (18:42 -0400)]
Establish conventions about global object names used in regression tests.
To ensure that "make installcheck" can be used safely against an existing
installation, we need to be careful about what global object names
(database, role, and tablespace names) we use; otherwise we might
accidentally clobber important objects. There's been a weak consensus that
test databases should have names including "regression", and that test role
names should start with "regress_", but we didn't have any particular rule
about tablespace names; and neither of the other rules was followed with
any consistency either.
This commit moves us a long way towards having a hard-and-fast rule that
regression test databases must have names including "regression", and that
test role and tablespace names must start with "regress_". It's not
completely there because I did not touch some test cases in rolenames.sql
that test creation of special role names like "session_user". That will
require some rethinking of exactly what we want to test, whereas the intent
of this patch is just to hit all the cases in which the needed renamings
are cosmetic.
There is no enforcement mechanism in this patch either, but if we don't
add one we can expect that the tests will soon be violating the convention
again. Again, that's not such a cosmetic change and it will require
discussion. (But I did use a quick-hack enforcement patch to find these
cases.)
Peter Eisentraut [Sun, 17 Jul 2016 13:15:37 +0000 (09:15 -0400)]
Use correct symbol for minimum int64 value
The old code used SEQ_MINVALUE to get the smallest int64 value. This
was done as a convenience to avoid having to deal with INT64_IS_BUSTED,
but that is obsolete now. Also, it is incorrect because the smallest
int64 value is actually SEQ_MINVALUE-1. Fix by using PG_INT64_MIN.
Tom Lane [Sat, 16 Jul 2016 20:25:43 +0000 (16:25 -0400)]
Improve test case exercising the sorting path for hash index build.
On second thought, we should probably do at least a minimal check that
the constructed index is valid, since the big problem with the most
recent breakage was not whether the sorting was correct but that the
index had incorrect hash codes placed in it.
Tom Lane [Sat, 16 Jul 2016 19:30:15 +0000 (15:30 -0400)]
Add regression test case exercising the sorting path for hash index build.
We've broken this code path at least twice in the past, so it's prudent
to have a test case that covers it. To allow exercising the code path
without creating a very large (and slow to run) test case, redefine the
sort threshold to be bounded by maintenance_work_mem as well as the number
of available buffers. While at it, fix an ancient oversight that when
building a temp index, the number of available buffers is not NBuffers but
NLocBuffer. Also, if assertions are enabled, apply a direct test that the
sort actually does return the tuples in the expected order.
Tom Lane [Sat, 16 Jul 2016 18:42:37 +0000 (14:42 -0400)]
Fix crash in close_ps() for NaN input coordinates.
The Assert() here seems unreasonably optimistic. Andreas Seltenreich
found that it could fail with NaNs in the input geometries, and it
seems likely to me that it might fail in corner cases due to roundoff
error, even for ordinary input values. As a band-aid, make the function
return SQL NULL instead of crashing.
Tom Lane [Sat, 16 Jul 2016 18:12:44 +0000 (14:12 -0400)]
Clarify usage of clientcert authentication option.
For some reason this option wasn't discussed at all in client-auth.sgml.
Document it there, and be more explicit about its relationship to the
"cert" authentication method. Per gripe from Srikanth Venkatesh.
I failed to resist the temptation to do some minor wordsmithing in the
same area, too.
Tom Lane [Sat, 16 Jul 2016 16:49:14 +0000 (12:49 -0400)]
Advance PG_CONTROL_VERSION.
This should have been done in commit 73c986adde5d73a5 which added several
new fields to pg_control, and again in commit 5028f22f6eb05798 which
changed the CRC algorithm, but it wasn't. It's far too late to fix it in
the 9.5 branch, but let's do so in 9.6, so that if a 9.6 postmaster is
started against a 9.4-era pg_control it will complain about a versioning
problem rather than a CRC failure. We already forced initdb/pg_upgrade
for beta3, so there's no downside to doing this now.
Andres Freund [Sat, 16 Jul 2016 00:49:48 +0000 (17:49 -0700)]
Fix torn-page, unlogged xid and further risks from heap_update().
When heap_update needs to look for a page for the new tuple version,
because the current one doesn't have sufficient free space, or when
columns have to be processed by the tuple toaster, it has to release the
lock on the old page during that. Otherwise there'd be lock ordering and
lock nesting issues.
To avoid concurrent sessions from trying to update / delete / lock the
tuple while the page's content lock is released, the tuple's xmax is set
to the current session's xid.
That unfortunately was done without any WAL logging, thereby violating
the rule that no XIDs may appear on disk, without an according WAL
record. If the database were to crash / fail over when the page level
lock is released, and some activity lead to the page being written out
to disk, the xid could end up being reused; potentially leading to the
row becoming invisible.
There might be additional risks by not having t_ctid point at the tuple
itself, without having set the appropriate lock infomask fields.
To fix, compute the appropriate xmax/infomask combination for locking
the tuple, and perform WAL logging using the existing XLOG_HEAP_LOCK
record. That allows the fix to be backpatched.
This issue has existed for a long time. There appears to have been
partial attempts at preventing dangers, but these never have fully been
implemented, and were removed a long time ago, in 11919160 (cf. HEAP_XMAX_UNLOGGED).
In master / 9.6, there's an additional issue, namely that the
visibilitymap's freeze bit isn't reset at that point yet. Since that's a
new issue, introduced only in a892234f830, that'll be fixed in a
separate commit.
Author: Masahiko Sawada and Andres Freund Reported-By: Different aspects by Thomas Munro, Noah Misch, and others
Discussion: CAEepm=3fWAbWryVW9swHyLTY4sXVf0xbLvXqOwUoDiNCx9mBjQ@mail.gmail.com
Backpatch: 9.1/all supported versions
Andres Freund [Fri, 15 Jul 2016 21:37:06 +0000 (14:37 -0700)]
Make HEAP_LOCK/HEAP2_LOCK_UPDATED replay reset HEAP_XMAX_INVALID.
0ac5ad5 started to compress infomask bits in WAL records. Unfortunately
the replay routines for XLOG_HEAP_LOCK/XLOG_HEAP2_LOCK_UPDATED forgot to
reset the HEAP_XMAX_INVALID (and some other) hint bits.
Luckily that's not problematic in the majority of cases, because after a
crash/on a standby row locks aren't meaningful. Unfortunately that does
not hold true in the presence of prepared transactions. This means that
after a crash, or after promotion, row level locks held by a prepared,
but not yet committed, prepared transaction might not be enforced.
Discussion: 20160715192319.ubfuzim4zv3rqnxv@alap3.anarazel.de
Backpatch: 9.3, the oldest branch on which 0ac5ad5 is present.
Tom Lane [Fri, 15 Jul 2016 21:22:56 +0000 (17:22 -0400)]
Avoid invalidating all foreign-join cached plans when user mappings change.
We must not push down a foreign join when the foreign tables involved
should be accessed under different user mappings. Previously we tried
to enforce that rule literally during planning, but that meant that the
resulting plans were dependent on the current contents of the
pg_user_mapping catalog, and we had to blow away all cached plans
containing any remote join when anything at all changed in pg_user_mapping.
This could have been improved somewhat, but the fact that a syscache inval
callback has very limited info about what changed made it hard to do better
within that design. Instead, let's change the planner to not consider user
mappings per se, but to allow a foreign join if both RTEs have the same
checkAsUser value. If they do, then they necessarily will use the same
user mapping at runtime, and we don't need to know specifically which one
that is. Post-plan-time changes in pg_user_mapping no longer require any
plan invalidation.
This rule does give up some optimization ability, to wit where two foreign
table references come from views with different owners or one's from a view
and one's directly in the query, but nonetheless the same user mapping
would have applied. We'll sacrifice the first case, but to not regress
more than we have to in the second case, allow a foreign join involving
both zero and nonzero checkAsUser values if the nonzero one is the same as
the prevailing effective userID. In that case, mark the plan as only
runnable by that userID.
The plancache code already had a notion of plans being userID-specific,
in order to support RLS. It was a little confused though, in particular
lacking clarity of thought as to whether it was the rewritten query or just
the finished plan that's dependent on the userID. Rearrange that code so
that it's clearer what depends on which, and so that the same logic applies
to both RLS-injected role dependency and foreign-join-injected role
dependency.
Note that this patch doesn't remove the other issue mentioned in the
original complaint, which is that while we'll reliably stop using a foreign
join if it's disallowed in a new context, we might fail to start using a
foreign join if it's now allowed, but we previously created a generic
cached plan that didn't use one. It was agreed that the chance of winning
that way was not high enough to justify the much larger number of plan
invalidations that would have to occur if we tried to cause it to happen.
In passing, clean up randomly-varying spelling of EXPLAIN commands in
postgres_fdw.sql, and fix a COSTS ON example that had been allowed to
leak into the committed tests.
This reverts most of commits fbe5a3fb7 and 5d4171d1c, which were the
previous attempt at ensuring we wouldn't push down foreign joins that
span permissions contexts.
Avoid serializability errors when locking a tuple with a committed update
When key-share locking a tuple that has been not-key-updated, and the
update is a committed transaction, in some cases we raised
serializability errors:
ERROR: could not serialize access due to concurrent update
Because the key-share doesn't conflict with the update, the error is
unnecessary and inconsistent with the case that the update hasn't
committed yet. This causes problems for some usage patterns, even if it
can be claimed that it's sufficient to retry the aborted transaction:
given a steady stream of updating transactions and a long locking
transaction, the long transaction can be starved indefinitely despite
multiple retries.
To fix, we recognize that HeapTupleSatisfiesUpdate can return
HeapTupleUpdated when an updating transaction has committed, and that we
need to deal with that case exactly as if it were a non-committed
update: verify whether the two operations conflict, and if not, carry on
normally. If they do conflict, however, there is a difference: in the
HeapTupleBeingUpdated case we can just sleep until the concurrent
transaction is gone, while in the HeapTupleUpdated case this is not
possible and we must raise an error instead.
Per trouble report from Olivier Dony.
In addition to a couple of test cases that verify the changed behavior,
I added a test case to verify the behavior that remains unchanged,
namely that errors are raised when a update that modifies the key is
used. That must still generate serializability errors. One
pre-existing test case changes behavior; per discussion, the new
behavior is actually the desired one.
Digging around bug #14245 I found that commit 6734a1cacd44f5b731933cbc93182b135b167d0c missed that NOT operation is
right associative in opposite to all other. This miss is resposible for
tsquery parser fail on sequence of NOT operations
During normalization of tsquery tree it tries to simplify nested NOT
operations but there it's obvioulsy missed that subsequent node could be
a leaf node (value node)
Bug #14245: Segfault on weird to_tsquery
Reported by David Kellum.
Tom Lane [Fri, 15 Jul 2016 14:58:39 +0000 (10:58 -0400)]
Improve documentation about search_path for SECURITY DEFINER functions.
Clarify that the reason for recommending that pg_temp be put last is to
prevent temporary tables from capturing unqualified table names. Per
discussion with Albe Laurenz.
Tom Lane [Thu, 14 Jul 2016 22:45:59 +0000 (18:45 -0400)]
Fix GiST index build for NaN values in geometric types.
GiST index build could go into an infinite loop when presented with boxes
(or points, circles or polygons) containing NaN component values. This
happened essentially because the code assumed that x == x is true for any
"double" value x; but it's not true for NaNs. The looping behavior was not
the only problem though: we also attempted to sort the items using simple
double comparisons. Since NaNs violate the trichotomy law, qsort could
(in principle at least) get arbitrarily confused and mess up the sorting of
ordinary values as well as NaNs. And we based splitting choices on box size
calculations that could produce NaNs, again resulting in undesirable
behavior.
To fix, replace all comparisons of doubles in this logic with
float8_cmp_internal, which is NaN-aware and is careful to sort NaNs
consistently, higher than any non-NaN. Also rearrange the box size
calculation to not produce NaNs; instead it should produce an infinity
for a box with NaN on one side and not-NaN on the other.
I don't by any means claim that this solves all problems with NaNs in
geometric values, but it should at least make GiST index insertion work
reliably with such data. It's likely that the index search side of things
still needs some work, and probably regular geometric operations too.
But with this patch we're laying down a convention for how such cases
ought to behave.
Per bug #14238 from Guang-Dih Lei. Back-patch to 9.2; the code used before
commit 7f3bd86843e5aad8 is quite different and doesn't lock up on my simple
test case, nor on the submitter's dataset.
Tom Lane [Wed, 13 Jul 2016 19:36:25 +0000 (15:36 -0400)]
Minor test adjustment.
Dept of second thoughts: given the RESET SESSION AUTHORIZATION that
was just added by commit cec550139, we don't need the reconnection
that used to be here. Might as well buy back a few microseconds.
Tom Lane [Wed, 13 Jul 2016 19:23:56 +0000 (15:23 -0400)]
Add a regression test case to improve code coverage for tuplesort.
Test the external-sort code path in CLUSTER for two different scenarios:
multiple-pass external sorting, and the best case for replacement
selection, where only one run is produced, so that no merge is required.
This test would have caught the bug fixed in commit 1b0fc8507, at
least when run with valgrind enabled.
In passing, add a short-circuit test in plan_cluster_use_sort() to make
dead certain that it selects sorting when enable_indexscan is off. As
things stand, that would happen anyway, but it seems like good future
proofing for this test.
Tom Lane [Tue, 12 Jul 2016 22:06:50 +0000 (18:06 -0400)]
Allow IMPORT FOREIGN SCHEMA within pl/pgsql.
Since IMPORT FOREIGN SCHEMA has an INTO clause, pl/pgsql needs to be
aware of that and avoid capturing the INTO as an INTO-variables clause.
This isn't hard, though it's annoying to have to make IMPORT a plpgsql
keyword just for this. (Fortunately, we have the infrastructure now
to make it an unreserved keyword, so at least this shouldn't break any
existing pl/pgsql code.)
Per report from Merlin Moncure. Back-patch to 9.5 where IMPORT FOREIGN
SCHEMA was introduced.
Tom Lane [Mon, 11 Jul 2016 22:14:29 +0000 (18:14 -0400)]
Print a given subplan only once in EXPLAIN.
We have, for a very long time, allowed the same subplan (same member of the
PlannedStmt.subplans list) to be referenced by more than one SubPlan node;
this avoids problems for cases such as subplans within an IndexScan's
indxqual and indxqualorig fields. However, EXPLAIN had not gotten the memo
and would print each reference as though it were an independent identical
subplan. To fix, track plan_ids of subplans we've printed and don't print
the same plan_id twice. Per report from Pavel Stehule.
BTW: the particular case of IndexScan didn't cause visible duplication
in a plain EXPLAIN, only EXPLAIN ANALYZE, because in the former case we
short-circuit executor startup before the indxqual field is processed by
ExecInitExpr. That seems like it could easily lead to other EXPLAIN
problems in future, but it's not clear how to avoid it without breaking
the "EXPLAIN a plan using hypothetical indexes" use-case. For now I've
left that issue alone.
Although this is a longstanding bug, it's purely cosmetic (no great harm
is done by the repeat printout) and we haven't had field complaints before.
So I'm hesitant to back-patch it, especially since there is some small risk
of ABI problems due to the need to add a new field to ExplainState.
In passing, rearrange order of fields in ExplainState to be less random,
and update some obsolete comments about when/where to initialize them.
Tom Lane [Mon, 11 Jul 2016 16:35:03 +0000 (12:35 -0400)]
Improve output of psql's \df+ command.
Add display of proparallel (parallel-safety) when the server is >= 9.6,
and display of proacl (access privileges) for all server versions.
Minor tweak of column ordering to keep related columns together.
Magnus Hagander [Mon, 11 Jul 2016 10:02:31 +0000 (12:02 +0200)]
Fix start WAL filename for concurrent backups from standby
On a standby, ThisTimelineID is always 0, so we would generate a
filename in timeline 0 even for other timelines. Instead, use starttli
which we have retreived from the controlfile.
Report by: Francesco Canovai in bug #14230
Author: Marco Nenciarini
Reviewed by: Michael Paquier and Amit Kapila
Tom Lane [Sat, 9 Jul 2016 20:47:38 +0000 (16:47 -0400)]
Fix TAP tests and MSVC scripts for pathnames with spaces.
Change assorted places in our Perl code that did things like
system("prog $path/file");
to do it more like
system('prog', "$path/file");
which is safe against spaces and other special characters in the path
variable. The latter was already the prevailing style, but a few bits
of code hadn't gotten this memo. Back-patch to 9.4 as relevant.
Tom Lane [Sat, 9 Jul 2016 19:00:22 +0000 (15:00 -0400)]
Improve recording of IA64 stack data.
Examination of the results from anole and gharial suggests that we're
only managing to track the size of one of the two stacks of IA64 machines.
Some googling gave the answer: on HPUX11, the register stack is reported
as a page type I don't see in pstat.h on my HPUX10 box. Let's try
testing for that.
Tom Lane [Fri, 8 Jul 2016 20:38:22 +0000 (16:38 -0400)]
Add more temporary code to record stack usage at server process exit.
After a look at preliminary results from commit 88cf37d2a86d5b66,
I realized it'd be a good idea to spew out the maximum depth measurement
seen by check_stack_depth. So add some quick-n-dirty code to do that.
Like the previous commit, this will be reverted once we've gathered
a set of buildfarm runs with it.
Tom Lane [Fri, 8 Jul 2016 16:01:08 +0000 (12:01 -0400)]
Add some temporary code to record stack usage at server process exit.
This patch is meant to gather information from the buildfarm members, and
will be reverted in a day or so. The idea is to try to find out the
high-water stack consumption while running the regression tests,
particularly on IA64 which is suspected to use much more stack than other
architectures. On machines with pmap, we can use that; but the IA64 farm
members are running HPUX, so also include some bespoke code for HPUX.
(I've tested the latter on HPUX 10/HPPA; not entirely sure it will work
on HPUX 11/IA64, but we'll soon find out.)
Robert Haas [Thu, 7 Jul 2016 17:47:16 +0000 (13:47 -0400)]
Properly adjust pointers when tuples are moved during CLUSTER.
Otherwise, when we abandon incremental memory accounting and use
batch allocation for the final merge pass, we might crash. This
has been broken since 0011c0091e886b874e485a46ff2c94222ffbf550.
Robert Haas [Thu, 7 Jul 2016 15:18:51 +0000 (11:18 -0400)]
Clarify resource utilization of parallel query.
temp_file_limit is a per-process limit, not a per-session limit across
all cooperating parallel processes; change wording accordingly, per a
suggestion from Tom Lane.
Also, document under max_parallel_workers_per_gather the fact that each
process involved in a parallel query may use as many resources as a
separate session. Caveat emptor.
Tom Lane [Thu, 7 Jul 2016 15:28:17 +0000 (11:28 -0400)]
Reduce stack space consumption in tzload().
While syncing our timezone code with IANA's updates in commit 1c1a7cbd6,
I'd chosen not to adopt the code they conditionally compile under #ifdef
ALL_STATE. The main thing that that drives is that the space for gmtime
and localtime timezone definitions isn't statically allocated, but is
malloc'd on first use. I reasoned we didn't need that logic: we don't have
localtime() at all, and we always initialize TimeZone to GMT so we always
need that one. But there is one other thing ALL_STATE does, which is to
make tzload() malloc its transient workspace instead of just declaring it
as a local variable. It turns out that that local variable occupies 78K.
Even worse is that, at least for common US timezone settings, there's a
recursive call to parse the "posixrules" zone name, making peak stack
consumption to select a time zone upwards of 150K. That's an uncomfortably
large fraction of our STACK_DEPTH_SLOP safety margin, and could result in
outright crashes if we try to reduce STACK_DEPTH_SLOP as has been discussed
recently. Furthermore, this means that the postmaster's peak stack
consumption is several times that of a backend running typical queries
(since, except on Windows, backends inherit the timezone GUC values and
don't ever run this code themselves unless you do SET TIMEZONE). That's
completely backwards from a safety perspective.
Hence, adopt the ALL_STATE rather than non-ALL_STATE variant of tzload(),
while not changing the other code aspects that symbol controls. The
risk of an ENOMEM error from malloc() seems less than that of a SIGSEGV
from stack overrun.
This should probably get back-patched along with 1c1a7cbd6 and followon
fixes, whenever we decide we have enough confidence in the updates to do
that.
Tom Lane [Mon, 4 Jul 2016 20:09:11 +0000 (16:09 -0400)]
Fix failure to handle conflicts in non-arbiter exclusion constraints.
ExecInsertIndexTuples treated an exclusion constraint as subject to
noDupErr processing even when it was not listed in arbiterIndexes, and
would therefore not error out for a conflict in such a constraint, instead
returning it as an arbiter-index failure. That led to an infinite loop in
ExecInsert, since ExecCheckIndexConstraints ignored the index as-intended
and therefore didn't throw the expected error. To fix, make the exclusion
constraint code path use the same condition as the index_insert call does
to decide whether no-error-for-duplicates behavior is appropriate. While
at it, refactor a little bit to avoid unnecessary list_member_oid calls.
(That surely wouldn't save anything worth noticing, but I find the code
a bit clearer this way.)
Per bug report from Heikki Rauhala. Back-patch to 9.5 where ON CONFLICT
was introduced.
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