Re: pg 8.1.2 performance issue

On Sunday March 26 2006 7:22 am, Ed L. wrote:
> On Saturday March 25 2006 9:55 pm, chris smith wrote:
> > On 3/26/06, Ed L. <pgsql@bluepolka.net> wrote:
> > > On Saturday March 25 2006 9:36 pm, Ed L. wrote:
> > > > I have a performance riddle, hoping someone can point me
> > > > in a helpful direction.  We have a pg 8.1.2 cluster
> > > > using Apache::Sessions and experiencing simple UPDATEs
> > > > taking sometimes 30+ seconds to do a very simply update,
> > > > no foreign keys, no triggers:
> > >
> > > The table has 6800 rows over 18000 pages, and is getting a
> > > minimum of many tens of thousands of updates per day with
> > > queries like this:
> >
> > If you're updating that much, how often are you running
> > 'analyze'? Are you running autovacuum? How often?
>
> I count on the built-in autovacuum to do do analyzes (per
> 8.1.2 docs).  I'm running autovacuum with the following
> non-default parameters:
>
>     autovacuum = on
>     autovacuum_naptime = 600 # 10 minutes

I also have these non-default settings:

    autovacuum_vacuum_cost_delay = 500
    autovacuum_vacuum_cost_limit = 200

Thanks,
Ed