References: <VisenaEmail.24.fd3487f9d1329566.147a8117731@tc7-on>  
Message-ID: <1407333872.37969.YahooMailNeo@web122303.mail.ne1.yahoo.com>
Date: Wed, 6 Aug 2014 07:04:32 -0700
From: Kevin Grittner <kgrittn@ymail.com>
Reply-To: Kevin Grittner <kgrittn@ymail.com>
Subject: Re: Query performing very bad and sometimes good
To: Andreas Joseph Krogh <andreas@visena.com>,
 "pgsql-performance@postgresql.org" <pgsql-performance@postgresql.org>
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Andreas Joseph Krogh <andreas@visena.com> wrote:

> Some-times it performs much better (but still not good)

As has already been suggested, that difference is almost certainly=20
due to differences in how much of the necessary data is cached or=20
what the query is competing with.

> Does anyone see anything obvious or have any hints what to
> investigate further?

We need more information to be able to say much.=A0 Please review
this page:

http://wiki.postgresql.org/wiki/SlowQueryQuestions

Knowing more about the hardware and the tables (including all
indexes) would help a lot, as well as all non-default configuration
settings.=A0 In particular, I'm curious whether there is an index on
the message_id column of origo_email_delivery.

--
Kevin Grittner
EDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company


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