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From: Steinar H. Gunderson <sgunderson@bigfoot.com>
To: pgsql-performance@postgresql.org
Subject: Re: What gets cached?
Date: Fri, 21 Oct 2005 14:40:38 +0200
Message-ID: <20051021124038.GA1928@samfundet.no> (raw)
In-Reply-To: <pan.2005.10.21.12.34.29.712700@portant.com>
References: <pan.2005.10.21.12.34.29.712700@portant.com>

On Fri, Oct 21, 2005 at 07:34:30AM -0500, Martin Nickel wrote:
> Let's say I do the same thing in Postgres.  I'm likely to have my very
> fastest performance for the first few queries until memory gets filled up.
>  The only time Postgres seems to take advantage of cached data is when I
>  repeat the same (or substantially the same) query.  I don't know of any
>  way to view what is actually cached at any point in time, but it seems
>  like "most recently used" rather than "most frequently used". 

What version are you using? There have been significant improvements to the
buffer manager in the last few versions. Most of the caching is done by your
OS, though, so that would probably influence the results quite a bit.

/* Steinar */
-- 
Homepage: http://www.sesse.net/




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