Re: slow query performance - Mailing list pgsql-general

From Dave Weaver
Subject Re: slow query performance
Date
Msg-id 200310301005.h9UA5L400802@server-2.twdl.co.uk
Whole thread Raw
In response to slow query performance  ("Dave Weaver" <davew@wsieurope.com>)
Responses Re: slow query performance  (Shridhar Daithankar <shridhar_daithankar@myrealbox.com>)
List pgsql-general

Shridhar Daithankar wrote:

> Dave Weaver wrote:

> > A simple "SELECT count(*) from obs" query takes around that sort of time

> > too.

>

> That is no test. Postgresql will always fetch the entire table.

 

OK, I wasn't aware of that.

 

> > I have run "vacuumdb --analyze obs", to little effect.

>

> Check http://www.varlena.com/varlena/GeneralBits/Tidbits/perf.html for general

> tuning tips

 

Thanks for the link - I will read and digest.

 

> and do a vacuum full if table is updated frequently. Also reindex

> the indexes after vacuum. It will take quite some time though.

 

The version of Postgres that I'm running (7.1.3) doesn't seem to have a "vacuum full".

I have reindexed after a vacuum, with liitle-to-no effect.

 

Dave.

 

 

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