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From: John Beaver <john.e.beaver@gmail.com>
To: Gaetano Mendola <mendola@gmail.com>
To: Pgsql-Performance <pgsql-performance@postgresql.org>
Subject: Re: large tables and simple "= constant" queries using indexes
Date: Thu, 10 Apr 2008 12:37:45 -0400
Message-ID: <47FE4259.7030704@gmail.com> (raw)
In-Reply-To: <47FE3DC7.4010700@gmail.com>
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Thanks Eric and Gaestano - interesting, and both examples of my
naivite. :)<br>
<br>
I tried running large select(*) queries on other tables followed by
another try at the offending query, and it was still fast. Just to be
absolutely sure this is a scalable solution, I'll try restarting my
computer in a few hours to see if it affects anything cache-wise.<br>
<br>
<br>
Gaetano Mendola wrote:
<blockquote cite="mid:47FE3DC7.4010700@gmail.com" type="cite">
  <pre wrap="">John Beaver wrote:

  </pre>
  <blockquote type="cite">
    <pre wrap="">- Trying the same constant a second time gave an instantaneous result,
I'm guessing because of query/result caching.
    </pre>
  </blockquote>
  <pre wrap=""><!---->
AFAIK no query/result caching is in place in postgres, what you are experiencing
is OS disk/memory caching.


Regards
Gaetano Mendola


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