Re: Feedback on auto-pruning approach

On Tue, 2006-03-28 at 12:23, Mark Liberman wrote:
> > Probably your biggest issue will be temporary files created by
> temporary tables, sorts that spill to disk, etc.
>
> Is there any way to monitor this so I can estimate?
>
> > What I'm confused by is the concern about disk space in the first
> place.
>
> We provide a device to customers that must run in an unattended
> fashion for as long as the hardward holds up. So, regardless of the
> disk size, they will run out at some time. Some of our solutions grow
> by 3.5 Gigs per day - and 6 months of history is not an unreasonable
> expectation. We've just decided we want to keep as much history as
> possible given space limitations.

If most of that is text, it should be fairly compressible.

So, how compressible are the data, and have you done some very basic
checks to see how much your postgresql data directory grows when you add
to the database. It's pretty easy to do. Just, as the postgres user:

cd $PGDATA
du -sh base
(load a couple gigs of data)
du -sh base

and compare the difference. It'll at least get you in the ball park.