On Thu, Dec 2, 2010 at 3:36 AM, Mario Splivalo <mario.splivalo@xxxxxxxxxx> wrote: > On 12/01/2010 09:43 AM, Pierre C wrote: >> >> Note that in both cases postgres reports that the FK checks take 92-120 >> milliseconds... which is a normal time for about 4000 rows. >> Inserting 4000 lines with just a few fields like you got should take >> quite much less than 1 s... >> >> Where the rest of the time goes, I have no idea. Disk thrashing ? Locks >> ? Gremlins ? >> >> - try it on a fresh copy of all your tables (CREATE TABLE, INSERT INTO >> SELECT) >> - try to put the WAL on a separate physical disk (or do a check with >> fsync=off) >> - try it on another computer >> - try it on another harddisk >> - run oprofile on a debug compile of postgres >> - it could even be the process title updates (I don't think so but...) >> - try a ramdisk tablespace > > I'm allready running it with fsync=off. The funny thing is, as I add new > realm it runs fine until the history table grows around 5M rows. After that > the slowdown is huge. Perhaps - that's the point at which the WAL volume becomes large enough to force a checkpoint in the middle of the operation? You might try turning on log_checkpoints. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
