Tom Lane [Wed, 29 Jun 2011 23:46:58 +0000 (19:46 -0400)]
Restore correct btree preprocessing of "indexedcol IS NULL" conditions.
Such a condition is unsatisfiable in combination with any other type of
btree-indexable condition (since we assume btree operators are always
strict). 8.3 and 8.4 had an explicit test for this, which I removed in
commit 29c4ad98293e3c5cb3fcdd413a3f4904efff8762, mistakenly thinking that
the case would be subsumed by the more general handling of IS (NOT) NULL
added in that patch. Put it back, and improve the comments about it, and
add a regression test case.
Per bug #6079 from Renat Nasyrov, and analysis by Dean Rasheed.
Move the PredicateLockRelation() call from nodeSeqscan.c to heapam.c. It's
more consistent that way, since all the other PredicateLock* calls are
made in various heapam.c and index AM functions. The call in nodeSeqscan.c
was unnecessarily aggressive anyway, there's no need to try to lock the
relation every time a tuple is fetched, it's enough to do it once.
This has the user-visible effect that if a seq scan is initialized in the
executor, but never executed, we now acquire the predicate lock on the heap
relation anyway. We could avoid that by taking the lock on the first
heap_getnext() call instead, but it doesn't seem worth the trouble given
that it feels more natural to do it in heap_beginscan().
Also, remove the retail PredicateLockTuple() calls from heap_getnext(). In
a seqscan, started with heap_begin(), we're holding a whole-relation
predicate lock on the heap so there's no need to lock the tuples
individually.
Simon Riggs [Mon, 27 Jun 2011 21:15:07 +0000 (22:15 +0100)]
Reduce impact of btree page reuse on Hot Standby by fixing off-by-1 error.
WAL records of type XLOG_BTREE_REUSE_PAGE were generated using a
latestRemovedXid one higher than actually needed because xid used was
page opaque->btpo.xact rather than an actually removed xid.
Noticed on an otherwise quiet system by Noah Misch.
Joe Conway [Sat, 25 Jun 2011 22:40:49 +0000 (15:40 -0700)]
Async dblink functions require a named connection, and therefore should
use DBLINK_GET_NAMED_CONN rather than DBLINK_GET_CONN.
Problem found by Peter Eisentraut and patch by Fujii Masao.
Tom Lane [Thu, 23 Jun 2011 03:03:11 +0000 (23:03 -0400)]
Undo overly enthusiastic de-const-ification.
s/const//g wasn't exactly what I was suggesting here ... parameter
declarations of the form "const structtype *param" are good and useful,
so put those occurrences back. Likewise, avoid casting away the const
in a "const void *" parameter.
Tom Lane [Wed, 22 Jun 2011 17:08:08 +0000 (13:08 -0400)]
Fix symlink for errcodes.h so it works in VPATH builds from tarballs.
backend/Makefile was treating errcodes.h as a header always generated
during build, but actually it's a header provided in tarballs. Hence,
must use the absolute-symlink recipe, not the relative-symlink one.
Per bug #6072 from Hartmut Raschick.
Remove pointless const qualifiers from function arguments in the SSI code.
As Tom Lane pointed out, "const Relation foo" doesn't guarantee that you
can't modify the data the "foo" pointer points to. It just means that you
can't change the pointer to point to something else within the function,
which is not very useful.
Tom Lane [Tue, 21 Jun 2011 18:41:05 +0000 (14:41 -0400)]
Apply upstream fix for blowfish signed-character bug (CVE-2011-2483).
A password containing a character with the high bit set was misprocessed
on machines where char is signed (which is most). This could cause the
preceding one to three characters to fail to affect the hashed result,
thus weakening the password. The result was also unportable, and failed
to match some other blowfish implementations such as OpenBSD's.
Since the fix changes the output for such passwords, upstream chose
to provide a compatibility hack: password salts beginning with $2x$
(instead of the usual $2a$ for blowfish) are intentionally processed
"wrong" to give the same hash as before. Stored password hashes can
thus be modified if necessary to still match, though it'd be better
to change any affected passwords.
In passing, sync a couple other upstream changes that marginally improve
performance and/or tighten error checking.
Back-patch to all supported branches. Since this issue is already
public, no reason not to commit the fix ASAP.
Adjust the alternative expected output file for prepared_xacts test case,
used when max_prepared_transactions=0, for the recent changes in the test
case.
Fix bug in PreCommit_CheckForSerializationFailure. A transaction that has
already been marked as PREPARED cannot be killed. Kill the current
transaction instead.
One of the prepared_xacts regression tests actually hits this bug. I
removed the anomaly from the duplicate-gids test so that it fails in the
intended way, and added a new test to check serialization failures with
a prepared transaction.
Fix bug introduced by recent SSI patch to merge ROLLED_BACK and
MARKED_FOR_DEATH flags into one. We still need the ROLLED_BACK flag to
mark transactions that are in the process of being rolled back. To be
precise, ROLLED_BACK now means that a transaction has already been
discounted from the count of transactions with the oldest xmin, but not
yet removed from the list of active transactions.
Tom Lane [Mon, 20 Jun 2011 18:33:20 +0000 (14:33 -0400)]
Fix thinko in previous patch for optimizing EXISTS-within-EXISTS.
When recursing after an optimization in pull_up_sublinks_qual_recurse, the
available_rels value passed down must include only the relations that are
in the righthand side of the new SEMI or ANTI join; it's incorrect to pull
up a sub-select that refers to other relations, as seen in the added test
case. Per report from BangarRaju Vadapalli.
While at it, rethink the idea of recursing below a NOT EXISTS. That is
essentially the same situation as pulling up ANY/EXISTS sub-selects that
are in the ON clause of an outer join, and it has the same disadvantage:
we'd force the two joins to be evaluated according to the syntactic nesting
order, because the lower join will most likely not be able to commute with
the ANTI join. That could result in having to form a rather large join
product, whereas the handling of a correlated subselect is not quite that
dumb. So until we can handle those cases better, #ifdef NOT_USED that
case. (I think it's okay to pull up in the EXISTS/ANY cases, because SEMI
joins aren't so inflexible about ordering.)
Back-patch to 8.4, same as for previous patch in this area. Fortunately
that patch hadn't made it into any shipped releases yet.
Peter Eisentraut [Sun, 19 Jun 2011 20:27:56 +0000 (23:27 +0300)]
Produce HISTORY file consistently as ASCII
The release notes may contain non-ASCII characters (for contributor
names), which lynx converts to the encoding determined by the current
locale. The get output that is deterministic and easily readable by
everyone, we make lynx produce LATIN1 and then convert that to ASCII
with transliteration for the non-ASCII characters.
Tom Lane [Sun, 19 Jun 2011 18:00:55 +0000 (14:00 -0400)]
Fix thinko in previous patch to always update pg_class.reltuples/relpages.
I mis-simplified the test where ANALYZE decided if it could get away
without doing anything: under the new regime, that's never allowed. Per
bug #6068 from Jeff Janes. Back-patch to 8.4, just like previous patch.
Tom Lane [Fri, 17 Jun 2011 23:13:08 +0000 (19:13 -0400)]
Don't use "cp -i" in the example WAL archive_command.
This is a dangerous example to provide because on machines with GNU cp,
it will silently do the wrong thing and risk archive corruption. Worse,
during the 9.0 cycle somebody "improved" the discussion by removing the
warning that used to be there about that, and instead leaving the
impression that the command would work as desired on most Unixen.
It doesn't. Try to rectify the damage by providing an example that is safe
most everywhere, and then noting that you can try cp -i if you want but
you'd better test that.
In back-patching this to all supported branches, I also added an example
command for Windows, which wasn't provided before 9.0.
Tom Lane [Fri, 17 Jun 2011 22:19:09 +0000 (18:19 -0400)]
Obtain table locks as soon as practical during pg_dump.
For some reason, when we (I) added table lock acquisition to pg_dump,
we didn't think about making it happen as soon as possible after the
start of the transaction. What with subsequent additions, there was
actually quite a lot going on before we got around to that; which sort
of defeats the purpose. Rearrange the order of calls in dumpSchema()
to close the risk window as much as we easily can. Back-patch to all
supported branches.
Robert Haas [Fri, 17 Jun 2011 18:28:45 +0000 (14:28 -0400)]
Add overflow checks to int4 and int8 versions of generate_series().
The previous code went into an infinite loop after overflow. In fact,
an overflow is not really an error; it just means that the current
value is the last one we need to return. So, just arrange to stop
immediately when overflow is detected.
Robert Haas [Fri, 17 Jun 2011 17:34:39 +0000 (13:34 -0400)]
Fix crash in CREATE UNLOGGED TABLE.
The code that created the init fork neglected to make sure that the
relation was open at the smgr level before attempting to invoke smgr.
This didn't happen every time; only when the relcache entry was rebuilt
along the way.
Update README-SSI. Add a section to describe the "dangerous structure" that
SSI is based on, as well as the optimizations about relative commit times
and read-only transactions. Plus a bunch of other misc fixes and
improvements.
Simon Riggs [Thu, 16 Jun 2011 09:17:59 +0000 (10:17 +0100)]
Respect Hot Standby controls while recycling btree index pages.
Btree pages were recycled after VACUUM deletes all records on a
page and then a subsequent VACUUM occurs after the RecentXmin
horizon is reached. Using RecentXmin meant that we did not respond
correctly to the user controls provide to avoid Hot Standby
conflicts and so spurious conflicts could be generated in some
workload combinations. We now reuse pages only when we reach
RecentGlobalXmin, which can be much later in the presence of long
running queries and is also controlled by vacuum_defer_cleanup_age
and hot_standby_feedback.
Tom Lane [Thu, 16 Jun 2011 01:45:23 +0000 (21:45 -0400)]
Use single quotes in preference to double quotes for protecting pathnames.
Per recommendation from Peter. Neither choice is bulletproof, but this
is the existing style and it does help prevent unexpected environment
variable substitution.
Tom Lane [Wed, 15 Jun 2011 23:05:11 +0000 (19:05 -0400)]
Rework parsing of ConstraintAttributeSpec to improve NOT VALID handling.
The initial commit of the ALTER TABLE ADD FOREIGN KEY NOT VALID feature
failed to support labeling such constraints as deferrable. The best fix
for this seems to be to fold NOT VALID into ConstraintAttributeSpec.
That's a bit more general than the documented syntax, but it allows
better-targeted syntax error messages.
In addition, do some mostly-but-not-entirely-cosmetic code review for
the whole NOT VALID patch.
Tom Lane [Wed, 15 Jun 2011 18:05:22 +0000 (14:05 -0400)]
Fix failure to account for memory used by tuplestore_putvalues().
This oversight could result in a tuplestore using much more than the
intended amount of memory. It would only happen in a code path that loaded
a tuplestore via tuplestore_putvalues(), and many of those won't emit huge
amounts of data; but cases such as holdable cursors and plpgsql's RETURN
NEXT command could have the problem. The fix ensures that the tuplestore
will switch to write-to-disk mode when it overruns work_mem.
The potential overrun was finite, because we would still count the space
used by the tuple pointer array, so the tuplestore code would eventually
flip into write-to-disk mode anyway. When storing wide tuples we would
go far past the expected work_mem usage before that happened; but this
may account for the lack of prior reports.
Back-patch to 8.4, where tuplestore_putvalues was introduced.
Tom Lane [Wed, 15 Jun 2011 17:15:05 +0000 (13:15 -0400)]
Fix oversights in pg_basebackup's -z (compression) option.
The short-form -z switch didn't work, for lack of telling getopt_long
about it; and even if specified long-form, it failed to do anything,
because the various tests elsewhere in the file would take
Z_DEFAULT_COMPRESSION (which is -1) as meaning "don't compress".
Per bug #6060 from Shigehiro Honda, though I editorialized on his patch
a bit.
The rolled-back flag on serializable xacts was pointless and redundant with
the marked-for-death flag. It was only set for a fleeting moment while a
transaction was being cleaned up at rollback. All the places that checked
for the rolled-back flag should also check the marked-for-death flag, as
both flags mean that the transaction will roll back. I also renamed the
marked-for-death into "doomed", which is a lot shorter name.
Make non-MVCC snapshots exempt from predicate locking. Scans with non-MVCC
snapshots, like in REINDEX, are basically non-transactional operations. The
DDL operation itself might participate in SSI, but there's separate
functions for that.
Kevin Grittner and Dan Ports, with some changes by me.
Tom Lane [Tue, 14 Jun 2011 16:00:37 +0000 (12:00 -0400)]
Fix assorted issues with build and install paths containing spaces.
Apparently there is no buildfarm critter exercising this case after all,
because it fails in several places. With this patch, build, install,
check-world, and installcheck-world pass for me on OS X.
Renumber 2PC resource managers so that compared to 9.0, predicate lock rmgr
is added to the end, and existing resource managers keep their old ids.
We're not going to guarantee on-disk compatibility for 2PC state files over
major releases, but it seems better to avoid changing the ids them anyway.
It will help anyone who might want to write external tools to inspect the
state files to work with files from different versions, if nothing else.
Per complaint from Tom Lane.
Alvaro Herrera [Mon, 13 Jun 2011 21:12:26 +0000 (17:12 -0400)]
Expand warnings on locks acquired by CREATE INDEX CONCURRENTLY
The previous wording wasn't explicit enough, which could misled readers
into thinking that the locks acquired are more restricted in nature than
they really are. The resulting optimism can be damaging to morale when
confronted with reality, as has been observed in the field.
Tom Lane [Fri, 10 Jun 2011 21:03:03 +0000 (17:03 -0400)]
Work around gcc 4.6.0 bug that breaks WAL replay.
ReadRecord's habit of using both direct references to tmpRecPtr and
references to *RecPtr (which is pointing at tmpRecPtr) triggers an
optimization bug in gcc 4.6.0, which apparently has forgotten about
aliasing rules. Avoid the compiler bug, and make the code more readable
to boot, by getting rid of the direct references. Improve the comments
while at it.
Back-patch to all supported versions, in case they get built with 4.6.0.
Tom Lane, with some cosmetic suggestions from Alex Hunsaker
Fix locking while setting flags in MySerializableXact.
Even if a flag is modified only by the backend owning the transaction, it's
not safe to modify it without a lock. Another backend might be setting or
clearing a different flag in the flags field concurrently, and that
operation might be lost because setting or clearing a bit in a word is not
atomic.
Make did-write flag a simple backend-private boolean variable, because it
was only set or tested in the owning backend (except when committing a
prepared transaction, but it's not worthwhile to optimize for the case of a
read-only prepared transaction). This also eliminates the need to add
locking where that flag is set.
Also, set the did-write flag when doing DDL operations like DROP TABLE or
TRUNCATE -- that was missed earlier.
Alvaro Herrera [Fri, 10 Jun 2011 17:43:02 +0000 (13:43 -0400)]
Use "transient" files for blind writes, take 2
"Blind writes" are a mechanism to push buffers down to disk when
evicting them; since they may belong to different databases than the one
a backend is connected to, the backend does not necessarily have a
relation to link them to, and thus no way to blow them away. We were
keeping those files open indefinitely, which would cause a problem if
the underlying table was deleted, because the operating system would not
be able to reclaim the disk space used by those files.
To fix, have bufmgr mark such files as transient to smgr; the lower
layer is allowed to close the file descriptor when the current
transaction ends. We must be careful to have any other access of the
file to remove the transient markings, to prevent unnecessary expensive
system calls when evicting buffers belonging to our own database (which
files we're likely to require again soon.)
This commit fixes a bug in the previous one, which neglected to cleanly
handle the LRU ring that fd.c uses to manage open files, and caused an
unacceptable failure just before beta2 and was thus reverted.
Alvaro Herrera [Thu, 9 Jun 2011 17:41:12 +0000 (13:41 -0400)]
Use "transient" files for blind writes
"Blind writes" are a mechanism to push buffers down to disk when
evicting them; since they may belong to different databases than the one
a backend is connected to, the backend does not necessarily have a
relation to link them to, and thus no way to blow them away. We were
keeping those files open indefinitely, which would cause a problem if
the underlying table was deleted, because the operating system would not
be able to reclaim the disk space used by those files.
To fix, have bufmgr mark such files as transient to smgr; the lower
layer is allowed to close the file descriptor when the current
transaction ends. We must be careful to have any other access of the
file to remove the transient markings, to prevent unnecessary expensive
system calls when evicting buffers belonging to our own database (which
files we're likely to require again soon.)
Fix the truncation logic of the OldSerXid SLRU mechanism. We can't pass
SimpleLruTruncate() a page number that's "in the future", because it will
issue a warning and refuse to truncate anything. Instead, we leave behind
the latest segment. If the slru is not needed before XID wrap-around, the
segment will appear as new again, and not be cleaned up until it gets old
enough again. That's a bit unpleasant, but better than not cleaning up
anything.
Also, fix broken calculation to check and warn if the span of the OldSerXid
SLRU is getting too large to fit in the 64k SLRU pages that we have
available. It was not XID wraparound aware.
Tom Lane [Wed, 8 Jun 2011 19:24:27 +0000 (15:24 -0400)]
Make citext's equality and hashing functions collation-insensitive.
This is an ugly hack to get around the fact that significant parts of the
core backend assume they don't need to worry about passing collation to
equality and hashing functions. That's true for the core string datatypes,
but citext should ideally have equality behavior that depends on the
specified collation's LC_CTYPE. However, there's no chance of fixing the
core before 9.2, so we'll have to live with this compromise arrangement for
now. Per bug #6053 from Regina Obe.
The code changes in this commit should be reverted in full once the core
code is up to speed, but be careful about reverting the docs changes:
I fixed a number of obsolete statements while at it.
Since start/stop/restart/reload/status is a kind of standard command
set, it seems odd to insert the special-purpose "promote" in between
the closely related "restart" and "reload". So put it after "status"
in code and documentation.
Put the documentation of the -U option in some sensible place.
Rewrite the synopsis sentence in help and documentation to make it
less of a growing mouthful.
Tom Lane [Wed, 8 Jun 2011 16:52:12 +0000 (12:52 -0400)]
Allow domains over arrays to match ANYARRAY parameters again.
This use-case was broken in commit 529cb267a6843a6a8190c86b75d091771d99d6a9
of 2010-10-21, in which I commented "For the moment, we just forbid such
matching. We might later wish to insert an automatic downcast to the
underlying array type, but such a change should also change matching of
domains to ANYELEMENT for consistency". We still lack consensus about what
to do with ANYELEMENT; but not matching ANYARRAY is a clear loss of
functionality compared to prior releases, so let's go ahead and make that
happen. Per complaint from Regina Obe and extensive subsequent discussion.
Make DDL operations play nicely with Serializable Snapshot Isolation.
Truncating or dropping a table is treated like deletion of all tuples, and
check for conflicts accordingly. If a table is clustered or rewritten by
ALTER TABLE, all predicate locks on the heap are promoted to relation-level
locks, because the tuple or page ids of any existing tuples will change and
won't be valid after rewriting the table. Arguably ALTER TABLE should be
treated like a mass-UPDATE of every row, but if you e.g change the datatype
of a column, you could also argue that it's just a change to the physical
layout, not a logical change. Reindexing promotes all locks on the index to
relation-level lock on the heap.
Kevin Grittner, with a lot of cosmetic changes by me.
Robert Haas [Wed, 8 Jun 2011 02:12:44 +0000 (22:12 -0400)]
Complain politely about access temp/unlogged tables during recovery.
This has never been supported, but we previously let md.c issue the
complaint for us at whatever point we tried to examine the backing file.
Now we print a nicer error message.
Per bug #6041, reported by Emanuel, and extensive discussion with Tom
Lane over where to put the check.