From: | Dror Matalon <dror(at)zapatec(dot)com> |
---|---|
To: | Aditya <aditya(at)grot(dot)org> |
Cc: | Josh Berkus <josh(at)agliodbs(dot)com>, sfpug(at)postgresql(dot)org |
Subject: | Re: Freebsd vs linux and hardware question |
Date: | 2003-09-22 17:57:59 |
Message-ID: | 20030922175759.GV97268@rlx11.zapatec.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | sfpug |
On Mon, Sep 22, 2003 at 10:42:14AM -0700, Aditya wrote:
> On Mon, Sep 22, 2003 at 10:24:29AM -0700, Josh Berkus wrote:
> > Dror,
> >
> > > But actually one of the big problems was solved when we ran VACUUM FULL
> > > on a problematic table. It shrank from 100 Megs to 6 Megs which on a
> > > local disk isn't as big a problem as on a NAS.
> > >
> > > We're also now running VACUUM ANALYZE on the table every five minutes
> > > instead of once a day and that helps too.
> >
> > What is your setting for max_fsm_pages? Have you compared it against the
> > results of logged VACUUM VERBOSE? And I'd be surprised if running VACUUM
> > ANALYZE ever 5 minutes is necessary ... VACUUM should do, with ANAYLZE maybe
> > once a day, unless your users are big on changing a large % of rows at once.
>
> these are the defaults in the config that we're using:
>
> #max_fsm_relations = 100 # min 10, fsm is free space map
> #max_fsm_pages = 10000 # min 1000, fsm is free space map
>
> FWIW, there are several thousand rows that get updated every few minutes.
>
> I'll let Dror answer as to why VACUUM ANALYZE vs. VACUUM alone.
When I run VACUUM every 5 minutes it takes 10 - 20 seconds to finish on
the average. Doesn't seem like the ANALYZE makes a big difference,
although I haven't tested that too carefully.
When I ran it every 10 minutes it took 30 - 40 seconds to finish. I'd
rather run it more often since it seems like it really affects response
time.
>
> > Finally, what about REINDEX?
I've run REINDEX once. My understanding is that you don't need to run it
on a continous basis (after all shouldn't the tree balance itself on
it's one?). Am I wrong with that?
>
> Because we have to remove all those addl. deleted/updated rows...
>
> Aditya
--
Dror Matalon, President
Zapatec Inc
1700 MLK Way
Berkeley, CA 94709
http://www.zapatec.com
From | Date | Subject | |
---|---|---|---|
Next Message | Josh Berkus | 2003-09-22 18:08:56 | Re: Freebsd vs linux and hardware question |
Previous Message | Josh Berkus | 2003-09-22 17:51:51 | Re: Freebsd vs linux and hardware question |