Re: When do I Vacuum ?

Hi Steve,

"Steve Brett" <steve.brett@e-mis.com> wrote
> hi,
>
> I've got a DB driven web application which currently has approx 298 inserts
> per day and 540 edits/deletes.
>
> This figure will change daily and currently i have a cron job set up to
> vacuum the database every hour during 'work time':
>
> 0 7-19/1,23 * * *       /usr/local/pgsql/bin/vacuumdb -z -d edb
> 30 7-19/4,23 * * *      /backup/dumpit

I do the same on my DB.

> I've also started reading Bruce's book (and what a fine book it is ... :-)
> and noticed that he suggests vacuuming once a day when the db is quiet.
>
> Would this be sufficient ? The database drives a web based
> calendar/appointment booking/reporting system i've written in php and is
> used extensively by 3 departments and has approx 200 people log in each day.
>
> Needless to say speed it paramount but I've got a sneaky feeling I might be
> vacuuming too often ....

I didn't read the book, but I also read that one vacuum per day would by
enough. But my DB runs on a P100 with 64MB ram :-( after 20 to 30
inserts it seems to slow down, so I vacuum once an houre (at main working time)
and now I've less problems 8)

HTH
  Carsten