Re: Adding foreign key performance - Mailing list pgsql-performance

From Jeff
Subject Re: Adding foreign key performance
Date
Msg-id 20031029090154.53b1e22d.threshar@torgo.978.org
Whole thread Raw
In response to Re: Adding foreign key performance  (Christopher Kings-Lynne <chriskl@familyhealth.com.au>)
List pgsql-performance
On Wed, 29 Oct 2003 09:47:28 +0800
Christopher Kings-Lynne <chriskl@familyhealth.com.au> wrote:

> >>Just loaded up delicious 7.4b5 and wow...
> >>
> >>sort_mem 8192:  137038ms [lots of tmp file activity]
> >>sort_mem 256000: 83109ms
> >

> 1. A full ANALYZE
> 2. A delete all from pg_statistic
>
I had previously analyze'd before I ran those numbers.
But I did it again with and without stats.

With:
Run 1 Time: 80157.21 ms
Run 2 Time: 80763.59 ms

Killed statistics:

Time: 80571.71 ms
Time: 80759.18 ms

Chances are it is going to seq scan regardless so the stats are rather
useless.  Perhaps in other scenarios it would help.


--
Jeff Trout <jeff@jefftrout.com>
http://www.jefftrout.com/
http://www.stuarthamm.net/

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