Skip site navigation (1) Skip section navigation (2)

Re: View performance

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Bruno Wolff III <bruno(at)wolff(dot)to>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: View performance
Date: 2002-12-26 19:50:14
Message-ID: 2713.1040932214@sss.pgh.pa.us (view raw or flat)
Thread:
Lists: pgsql-performance
Bruno Wolff III <bruno(at)wolff(dot)to> writes:
> By disabling merge joins and using the updated view, I got the query down
> to about 25% of its original runtime.
> Note the query estimate is off by a factor of more than 10.

This seems to indicate some estimation problems in cost_hashjoin; the
estimated cost for the hashjoin is evidently a lot higher than it should
be.

Are you interested in digging into this; or could you send me a dump of
the tables used in the view and query, so I could look into it?

			regards, tom lane

In response to

Responses

pgsql-performance by date

Next:From: Bruno Wolff IIIDate: 2002-12-26 20:36:56
Subject: Re: View performance
Previous:From: Tom LaneDate: 2002-12-26 19:42:39
Subject: Re: View performance

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group