Re: Why vacuum?

* Martin A. Marques <martin(at)math(dot)unl(dot)edu(dot)ar> [001213 15:15] wrote:
> El Mié 13 Dic 2000 16:41, bpalmer escribió:
> > I noticed the other day that one of my pg databases was slow, so I ran
> > vacuum on it, which brought a question to mind: why the need? I looked
> > at my oracle server and we aren't doing anything of the sort (that I can
> > find), so why does pg need it? Any info?
>
> I know nothing about Oracle, but I can tell you that Informix has an update
> statistics, which I don't know if it's similar to vacuum, but....
> What vacuum does is clean the database from rows that were left during
> updates and deletes, non the less, the tables get shrincked, so searches get
> faster.

Yes, postgresql requires vacuum quite often otherwise queries and
updates start taking ungodly amounts of time to complete. If you're
having problems because vacuum locks up your tables for too long
you might want to check out:

http://people.freebsd.org/~alfred/vacfix/

It has some tarballs that have patches to speed up vacuum depending
on how you access your tables you can see up to a 20x reduction in
vacuum time.

--
-Alfred Perlstein - [bright(at)wintelcom(dot)net|alfred(at)freebsd(dot)org]
"I have the heart of a child; I keep it in a jar on my desk."