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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Nikolas Everett <nik9000@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: explain analyze reports that my queries are fast but they run very slowly
Date: Thu, 27 Dec 2012 16:33:21 -0500
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Nikolas Everett <nik9000@gmail.com> writes:
> We straced the backend during the explain and it looked like the open
> commands were taking several seconds each.

Kind of makes me wonder if you have a whole lot of tables ("whole lot"
in this context probably means tens of thousands) and are storing the
database on a filesystem that doesn't scale well to lots of files in one
directory.  If that's the explanation, the reason the 8.3 installation
was okay was likely that it was stored on a more modern filesystem.

BTW, please keep the list cc'd on replies.

			regards, tom lane


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