Re: Huge performance problem between 7.4.1 and 8.0.3 - CS issue?

In regards to
http://archives.postgresql.org/pgsql-performance/2005-07/msg00261.php

Tom Says:
> ... as indeed it does according to Robert's recent reports.  Still
> awaiting the definitive test, but I'm starting to think this is another
> case of the strange behavior Ian Westmacott exhibited.

Ok.  This morning at around 7:30am I started tests against a freshly VACUUM FULL
ANALYZE 803 database with the vacuum delay on and cron running vacuum analyze
every 5 minutes.

Around 8:15 I was starting to receive hits of a few seconds of high CS hits,
higher than the previous 7 hour run on 741.  I changed the vacuum delay to 0 and
HUP'ed the server (how can I see the value vacuum_cost_delay run time?).  By
10:30, I had vacuum jobs backed up since 9:20 and the queries were over 75
seconds.

I'm currently running on 741 as I need to get work done today ;-)  I'll restart
the 803 db, vacuum full analyze again and next opportunity (maybe tonight),
start runs again with cron vacuum and a vacuum_cost_delay of 0, unless I should
try something else?

Cheers,
Rob

--

Robert Creager
Advisory Software Engineer
Phone 303.673.2365
Pager 888.912.4458
Fax   303.661.5379
StorageTek