From: Robert Creager <Robert_Creager@StorageTek.com>
To: tgl@sss.pgh.pa.us
To: matthew@zeut.net
To: pgsql-performance@postgresql.org
Cc: Andy Hewitt III <ralph_hewitt_iii@StorageTek.com>
Subject: Re: Huge performance problem between 7.4.1 and 8.0.3 - CS issue?
Date: Mon, 18 Jul 2005 11:49:52 -0600
Message-ID: <20050718114952.00004ac5@C118181.stortek.com> (raw)
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
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To: pgsql-performance@postgresql.org
Cc: Robert_Creager@StorageTek.com, tgl@sss.pgh.pa.us, matthew@zeut.net, ralph_hewitt_iii@StorageTek.com
Subject: Re: Huge performance problem between 7.4.1 and 8.0.3 - CS issue?
In-Reply-To: <20050718114952.00004ac5@C118181.stortek.com>
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