Re: [PERFORM] help with understanding EXPLAIN

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