Message-ID: <4CB8FD47.7090101@postnewspapers.com.au>
Date: Sat, 16 Oct 2010 09:17:59 +0800
From: Craig Ringer <craig@postnewspapers.com.au>
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To: Brandon Casci <brandon@loudcaster.com>,
	"List, Postgres" <pgsql-general@postgresql.org>
Subject: Re: [PERFORM] help with understanding EXPLAIN
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On 10/14/2010 05:18 AM, Brandon Casci wrote:
> Hello
>
> I have an application hosted on Heroku. They use postgres. It's more or
> less abstracted away, but I can get some performance data from New
> Relic. For the most part, performance is ok, but now and then some
> queries take a few seconds, and spike up to 15 or even 16 seconds! Ouch!
>
> This is the most detailed information I could get form New Relic. Do you
> have any suggestions how I could improve the performance?

That query plan is nearly illegible, and it contains no information 
about how the query actually executed or how many rows were fetched from 
various tables. I can't personally see any way to give you useful advice 
based on that information.

I know you're going through a third party, but do think you could get 
them to post the original form, unmangled by mail clients and whatever 
else they've done to it, here? :

http://explain.depesz.com

Get them to use EXPLAIN ANALYZE rather than plain EXPLAIN, and to 
provide the text of the query that generated the plan.

--
Craig Ringer