From: Craig Ringer <craig@postnewspapers.com.au>
To: Brandon Casci <brandon@loudcaster.com>
To: List, Postgres <pgsql-general@postgresql.org>
Subject: Re: [PERFORM] help with understanding EXPLAIN
Date: Sat, 16 Oct 2010 09:17:59 +0800
Message-ID: <4CB8FD47.7090101@postnewspapers.com.au> (raw)
In-Reply-To: <AANLkTinocNKGsOLCJp34WDT=B_ps1js_xKY7MDo8Dcdq@mail.gmail.com>
References: <AANLkTinocNKGsOLCJp34WDT=B_ps1js_xKY7MDo8Dcdq@mail.gmail.com>
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: craig@postnewspapers.com.au, brandon@loudcaster.com, pgsql-general@postgresql.org
Subject: Re: [PERFORM] help with understanding EXPLAIN
In-Reply-To: <4CB8FD47.7090101@postnewspapers.com.au>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox