Date: Mon, 18 Apr 2011 18:12:41 +0000
From: John Rouillard <rouilj@renesys.com>
To: "pgsql-performance@postgresql.org" <pgsql-performance@postgresql.org>
Subject: Assessing performance of fetches
Message-ID: <20110418181241.GF27218@renesys.com>
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Hi all:

An application running against a postgres 8.4.5 database under CentOS
5.5 uses cursors (I think via SqlAlchemy). To look for database
performance issues I log any query that takes > 2 seconds to complete.

I am seeing:

  2011-04-16 00:55:33 UTC user@database(3516): LOG:  duration:
     371954.811 ms  statement: FETCH FORWARD 1 FROM c_2aaaaaaeea50_a08

While I obviously have a problem here, is there any way to log the
actual select associated with the cursor other than logging all
statements?

Also once I have the select statement, does the fact that is is
associated with a fetch/cursor change the steps I should take in
tuning it compared to somebody just issuing a normal select?

Thanks for any ideas.

-- 
				-- rouilj

John Rouillard       System Administrator
Renesys Corporation  603-244-9084 (cell)  603-643-9300 x 111