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From: Laurent Raufaste <analogue@glop.org>
To: pgsql-performance@postgresql.org
Subject: Re: PG writes a lot to the disk
Date: Fri, 21 Mar 2008 14:45:28 +0100
Message-ID: <669dc9710803210645m530b492cs6de98f215bcecb23@mail.gmail.com> (raw)
In-Reply-To: <87prtoqkdk.fsf@oxford.xeocode.com>
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	<87prtoqkdk.fsf@oxford.xeocode.com>

2008/3/21, Gregory Stark <stark@enterprisedb.com>:
>
> Well that's true it does. But only once per row. So analyze would have set the
>  bit on every row. You could do the same thing with something ligter like
>  "select count(*) from <table>".

Well, the table has been analyzed, I did SELECT, PG write on the
table. That's a fact.

But it's also true (I juste tested it) that every file of a table is
modified by a SELECT COUNT.
>
>  Tom's thinking was that you would only expect a high update rate for a short
>  time until all those bits were set.
>
>  Slony's inserts, updates, and deletes count as updates to the table as well.
>

Slony is shut down when I'm testing.

-- 
Laurent Raufaste
<http://www.glop.org/;



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