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Cc: Tomas Vondra <tv@fuzzy.cz>,
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From: Robert Haas <robertmhaas@gmail.com>
Subject: Re: Performance
Date: Tue, 26 Apr 2011 01:30:58 -0400
To: Claudio Freire <klaussfreire@gmail.com>
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On Apr 14, 2011, at 2:49 AM, Claudio Freire <klaussfreire@gmail.com> wrote:
> This particular factor is not about an abstract and opaque "Workload"
> the server can't know about. It's about cache hit rate, and the server
> can indeed measure that.

The server can and does measure hit rates for the PG buffer pool, but to my k=
nowledge there is no clear-cut way for PG to know whether read() is satisfie=
d from the OS cache or a drive cache or the platter.

...Robert