Re: [Win32] Problem with rename()

Peter Brant <peter.brant@wicourts.gov>

From: "Peter Brant" <Peter.Brant@wicourts.gov>
To: "Tom Lane" <tgl@sss.pgh.pa.us>
Cc: <pgsql-bugs@postgresql.org>
Date: 2006-04-21T15:02:50Z
Lists: pgsql-bugs
This is probably somewhat superfluous, but we had another one these
incidents last night whose details confirm your explanation here.

[2006-04-21 00:22:19.500 ] 2452 LOG:  could not rename file
"pg_xlog/000000010000011A0000004C" to
"pg_xlog/000000010000011A00000071", continuing to try

the autovacuums (which wouldn't actually have been vacuuming anything
since update traffic would have stopped by then) continued until:

[2006-04-21 01:57:35.968 ] 4048 LOG:  autovacuum: processing database
"bigbird"

and the Web site first started noticing timeouts at 01:31:42,827.

Overnight traffic is so light that 70 minutes to work through 32K / 2
transactions is probably about right.

Pete

>>> Tom Lane <tgl@sss.pgh.pa.us> 04/18/06 9:01 pm >>>
[ thinks for awhile longer ... ]  No, I take that back.  Once you'd
exhausted the current pg_clog page (32K transactions), even read-only
transactions would be blocked by the need to create a new pg_clog page
(which is a WAL-logged action).  A read-only transaction never
actually
makes a WAL entry, but it does still consume an XID and hence a slot
on
the current pg_clog page.  So I just hadn't tried enough transactions.