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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Greg Smith <gsmith@gregsmith.com>
Cc: Matthew Wakeling <matthew@flymine.org>
Cc: pgsql-performance@postgresql.org
Subject: Re: I/O on select count(*)
Date: Mon, 19 May 2008 11:53:49 -0400
Message-ID: <5899.1211212429@sss.pgh.pa.us> (raw)
In-Reply-To: <Pine.GSO.4.64.0805191137480.25115@westnet.com>
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Greg Smith <gsmith@gregsmith.com> writes:
> The real question in my mind is why this turns into a bottleneck before 
> the similar task of cleaning the 16MB XLOG segment does.

Because we do the latter off-line, or at least try to.

			regards, tom lane



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