BUG #6484: pgstat wait timeout

The following bug has been logged on the website:

Bug reference:      6484
Logged by:          Charlie Neo
Email address:      cneo@accessdata.com
PostgreSQL version: 9.0.6
Operating system:   Windows Server 2008 R2 Enterprise
Description:=20=20=20=20=20=20=20=20

During heavy database loading, "pgstat wait timeout" is showing up in the
logs. When this happens pgstat.stat file stop updating. Stats in
pg_stat_user_tables also stop updating. Resulting in autovacuum not
triggering and greatly degrades performs. Killing the stats collection
process causing it to re-spawn does not help, as it will quickly go back
into the same state without any new stats collected.

Stack trace of the process postgres.exe -forkcol

ntoskrnl.exe!memset+0x64a
ntoskrnl.exe!KeWaitForMultipleObjects+0xf5d
ntoskrnl.exe!KeWaitForMultipleObjects+0x26a
ntoskrnl.exe!NtWaitForSingleObject+0x40f
ntoskrnl.exe!NtWaitForSingleObject+0x77e
ntoskrnl.exe!KeSynchronizeExecution+0x3a43
ntdll.dll!ZwWaitForMultipleObjects+0xa
KERNELBASE.dll!GetCurrentProcess+0x40
kernel32.dll!WaitForMultipleObjectsEx+0xb3
postgres.exe!reltimesend+0x1f8d50
postgres.exe!reltimesend+0x1f9053
postgres.exe!reltimesend+0x2054af
postgres.exe!reltimesend+0x20aa85
postgres.exe!reltimesend+0x14af4e
postgres.exe!reltimesend+0x38a65d
kernel32.dll!BaseThreadInitThunk+0xd
ntdll.dll!RtlUserThreadStart+0x21