BufferAlloc tries to insert a new mapping entry before deleting the old one
for a buffer, we have a transient need for more than NBuffers entries ---
one more in 8.1, and as many as NUM_BUFFER_PARTITIONS more in CVS HEAD.
In theory this could lead to an "out of shared memory" failure if shmem
had already been completely claimed by the time the extra entries were
needed.
recovery. In the first place, it doesn't work because slru's
latest_page_number isn't set up yet (this is why we've been hearing reports
of strange "apparent wraparound" log messages during crash recovery, but
only from people who'd managed to advance their next-mxact counters some
considerable distance from 0). In the second place, it seems a bit unwise
to be throwing away data during crash recovery anwyway. This latter
consideration convinces me to just disable truncation during recovery,
rather than computing latest_page_number and pushing ahead.
EINTR; the stats code was failing to do this and so were a couple of places
in the postmaster. The stats code assumed that recv() could not return EINTR
if a preceding select() showed the socket to be read-ready, but this is
demonstrably false with our Windows implementation of recv(), and it may
not be the case on all Unix variants either. I think this explains the
intermittent stats regression test failures we've been seeing, as well
as reports of stats collector instability under high load on Windows.
Backpatch as far as 8.0.
a table. Otherwise a USING clause that yields NULL can leave the table
violating its constraint (possibly there are other cases too). Per report
from Alexander Pravking.
> Upstream confirmed my reply in the last mail in [1]: the complete
> escaping logic in DBMirror.pl is seriously screwew.
>
> [1] http://archives.postgresql.org/pgsql-bugs/2006-06/msg00065.php
I finally found some time to debug this, and I think I found a better
patch than the one you proposed. Mine is still hackish and is still a
workaround around a proper quoting solution, but at least it repairs
the parsing without introducing the \' quoting again.
I consider this a band-aid patch to fix the recent security update.
PostgreSQL gurus, would you consider applying this until a better
solution is found for DBMirror.pl?
Olivier, can you please confirm that the patch works for you, too?
Backpatched to 8.0.X.
Martin Pitt
analyzing, so that future analyze threshold calculations don't get confused.
Also, make sure we correctly track the decrease of live tuples cause by
deletes.
Per report from Dylan Hansen, patches by Tom Lane and me.
palloc() will normally round allocation requests up to the next power of 2,
so make dynahash choose allocation sizes that are as close to a power of 2
as possible.
Back-patch to 8.1 --- the problem exists further back, but a much larger
patch would be needed and it doesn't seem worth taking any risks.
opposed to what other versions apparently do, so it's not safe to print an
error message. Besides, getopt_long itself already did, so it's redundant
anyway.
This is disallowed by the SQL spec because it doesn't have any very sensible
interpretation. Historically Postgres has allowed it but behaved strangely.
As of PG 8.1 a server crash is possible if the MIN/MAX index optimization gets
applied; rather than try to "fix" that, it seems best to just enforce the
spec restriction. Per report from Josh Drake and Alvaro Herrera.
initially be 0. This is needed as a previous ABORT might have wiped out
an automatically opened transaction without maintaining the cursor count.
- Fix regression test expected file for the correct ERROR message, which
we now get given the above bug fix.
We have once or twice seen failures suggesting that control didn't get
to the exception block before the timeout elapsed, which is unlikely
but not impossible in a parallel regression test (with a dozen other
backends competing for cycles). This change doesn't completely prevent
the problem of course, but it should reduce the probability enough that
we don't see it anymore. Per buildfarm results.
already-aborted transaction block. GetSnapshotData throws an Assert if
not in a valid transaction; hence we mustn't attempt to set a snapshot
for the function until after checking for aborted transaction. This is
harmless AFAICT if Asserts aren't enabled (GetSnapshotData will compute
a bogus snapshot, but it doesn't matter since HandleFunctionRequest will
throw an error shortly anywy). Hence, not a major bug.
Along the way, add some ability to log fastpath calls when statement
logging is turned on. This could probably stand to be improved further,
but not logging anything is clearly undesirable.
Backpatched as far as 8.0; bug doesn't exist before that.
was invoking obj_description() for each large object chunk, instead of once
per large object. This code is new as of 8.1, which may explain why the
problem hadn't been noticed already.
LWLocks during a panic exit. This avoids the possible self-deadlock pointed
out by Qingqing Zhou. Also, I noted that an error during LoadFreeSpaceMap()
or BuildFlatFiles() would result in exit(0) which would leave the postmaster
thinking all is well. Added a critical section to ensure such errors don't
allow startup to proceed.
Backpatched to 8.1. The 8.0 code is a bit different and I'm not sure if the
problem exists there; given we've not seen this reported from the field, I'm
going to be conservative about backpatching any further.
choose_bitmap_and(). It was way too fuzzy --- per comment, it was meant to be
1% relative difference, but was actually coded as 0.01 absolute difference,
thus causing selectivities of say 0.001 and 0.000000000001 to be treated as
equal. I believe this thinko explains Maxim Boguk's recent complaint. While
we could change it to a relative test coded like compare_fuzzy_path_costs(),
there's a bigger problem here, which is that any fuzziness at all renders the
comparison function non-transitive, which could confuse qsort() to the point
of delivering completely wrong results. So forget the whole thing and just
do an exact comparison.
Teodor Sigaev