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To: "Steven Flatt" <steven.flatt@gmail.com>
cc: pgsql-performance@postgresql.org
Subject: Re: Insertion to temp table deteriorating over time 
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Comments: In-reply-to "Steven Flatt" <steven.flatt@gmail.com>
	message dated "Fri, 15 Dec 2006 12:55:46 -0500"
Date: Fri, 15 Dec 2006 13:06:46 -0500
Message-ID: <12508.1166206006@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
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"Steven Flatt" <steven.flatt@gmail.com> writes:
> Our application is such that there is a great deal of activity at the
> beginning of the hour and minimal activity near the end of the hour.

OK ...

> The truncate and re-fill process is done once per hour, at the end of the
> high-load cycle, so I doubt that's even a big contributor to the number of
> removable rows in pg_class.

Oh, then where *are* the removable rows coming from?  At this point I
think that the truncate/refill thing is not the culprit, or at any rate
is only one part of a problematic usage pattern that we don't see all of
yet.

			regards, tom lane