Re: Join problem

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Silke Trissl <trissl(at)informatik(dot)hu-berlin(dot)de>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: Join problem
Date: 2004-04-28 12:52:20
Message-ID: 27627.1083156740@sss.pgh.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-performance

Silke Trissl <trissl(at)informatik(dot)hu-berlin(dot)de> writes:
> I found out, that the change of the operator from '~*' to '=' for the
> item.description brought a great boost in performance (425 secs to 1
> sec!), but not in cost (Query plans at the end).

The main problem seems to be bad estimation of the number of rows
extracted from the item table. Have you ANALYZEd that table lately?

regards, tom lane

In response to

Browse pgsql-performance by date

  From Date Subject
Next Message Tom Lane 2004-04-28 13:05:04 Re: planner/optimizer question
Previous Message Rod Taylor 2004-04-28 12:23:35 Re: Simply join in PostrgeSQL takes too long