Date: Tue, 19 Jul 2005 12:09:51 -0600
From: Robert Creager <Robert_Creager@StorageTek.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Robert Creager <Robert_Creager@StorageTek.com>,
	pgsql-performance@postgresql.org,
	Andy Hewitt III <ralph_hewitt_iii@StorageTek.com>
Subject: Re: Huge performance problem between 7.4.1 and 8.0.3 - CS issue?
Message-ID: <20050719120951.00002520@C118181.stortek.com>
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On Tue, 19 Jul 2005 12:54:22 -0400
Tom Lane <tgl@sss.pgh.pa.us> wrote:

> Hmm, I hadn't thought about the possible impact of multiple concurrent
> vacuums.  Is the problem caused by that, or has performance already gone
> into the tank by the time the cron-driven vacuums are taking long enough
> to overlap?

Don't know just yet.  When I run the vacuums manually on a healthy system on
741, they take less than 30 seconds.  I've stopped the cron vacuum and canceled
all the outstanding vacuum processes, but the 803 is still struggling (1/2 hour
later).

I'll re-start the database, vacuum full analyze and restart the runs without the
cron vacuum running.

Cheers,
Rob