Re: [BUGS] Rapid deteriation of performance (might be caused by tsearch?) in 7.3.2 - Mailing list pgsql-performance

From Robert John Shepherd
Subject Re: [BUGS] Rapid deteriation of performance (might be caused by tsearch?) in 7.3.2
Date
Msg-id 001e01c2fabd$9edfb860$f3b0313e@LAIKA
Whole thread Raw
In response to Re: [BUGS] Rapid deteriation of performance (might be caused by  (Stephan Szabo <sszabo@megazone23.bigpanda.com>)
Responses Re: [BUGS] Rapid deteriation of performance (might be
List pgsql-performance
> > Up until a few days ago I have been running Postgresl 7.2.3 with
Tsearch
> > from the contrib dir, but at various times the performance of the
> > database would suddenly and rapidly deteriate so that queries which
> > previously took 500ms then took 8 or 9 seconds.

> Hmm, what are the before and after explain analyze results?  Also,
what
> are your conf settings for shared buffers, sort memory and the fsm
> parameters?

shared_buffers = 40960
sort_mem = 20480
#max_fsm_relations = 1000
#max_fsm_pages = 10000

As you can see I've not uncommented or touched the fsm parameters, I
have no idea what they do. Optimisation wise I have only played with
shared_buffers, sort_mem and max_connections.


> > The only cure is a backup and restore of the database

> Did you do a regular vacuum or vacuum full?  If only the former, it's
> possible that you need to either vacuum more frequently and/or raise
the
> free space map settings in your configuration file.

I've been running this daily:

    vacuumdb -h localhost -a -z

Should I be using the full switch then?

I'll get back to you on the other questions if you think they are still
needed.


> pgsql-performance is a better list, so I've replied to there.  You'll
> probably need to join in order to reply to list.

Thanks, especially for not shouting at me heh, this is stressful enough
as it is.


Yours Unwhettedly,
Robert John Shepherd.

Editor
DVD REVIEWER
The UK's BIGGEST Online DVD Magazine
http://www.dvd.reviewer.co.uk

For a copy of my Public PGP key, email: pgp@robertsworld.org.uk


pgsql-performance by date:

Previous
From: Stephan Szabo
Date:
Subject: Re: [BUGS] Rapid deteriation of performance (might be caused by
Next
From: Stephan Szabo
Date:
Subject: Re: [BUGS] Rapid deteriation of performance (might be