On Mon, May 26, 2008 at 09:02:51AM -0300, Rafael Domiciano wrote:

> maintenance. But VACUUM FULL is used by more than 5 years, so VACUUM is a
> culture in the company. 

VACUUM is good.  VACUUM FULL is bad.  Even if they've been using it more
than 5 years, it's a bad idea.  (There are plenty of things that people did
for long periods of time that we no longer think are a good idea.  Some of
these are big -- selling people into slavery, say -- and some are small --
running open SMTP relays.  The thing is that the world changes, and saying
that you've done something a long time is not a good argument on its own.)

> I would like to know if you could pass me a forum or a list of messages on
> Postgres or maintenance in DB.

The manual has a long section on this.

> I'll give a new search in the documentation to find something about slony's
> vacuum and how to stop that.

Don't.  It's a bad idea.

> The problem is that I have an external application, and when the Slony's
> vacuum is running the application begins to slow down and give time-out.

I suspect what's happening is that you are running up against your
hardware's limitations.  Try collecting iostat during the period.  You will
likely find that you are at or near 100% of your disk's transfer capacity. 
That's what you need to fix.  You will cause worse problems if you don't
allow Slony to do its vacuuming on its own schedule.

A