Re: database size question

On Dec 19, 2007 11:53 AM, Mija Lee <mija(at)scharp(dot)org> wrote:

> Hi:
>
> I have a discrepancy in database size that I don't quite understand. I'm
> using postgres 8.1.3 on solaris 10. I have two databases on the same
> machine - the production database and a staging database. The production
> database is 9 GB, and growing fairly rapidly. Recently I did a dump and
> restore of the production database to the staging database. The
> recreated staging database was only 2 GB (approximately). There were no
> errors in the reload.
>
> I compared the two databases in terms of number of records, and then
> actual table size. At first I thought that there was a problem with the
> connection pool in the application which in turn was keeping large
> temporary tables around. This was part of the problem but only accounted
> for less than 1 GB of the difference. The real tables are different
> sizes. The ones that seem to show the most difference are tables that
> have the most churn: much of the data is deleted and reinserted nightly.
>
> The database server has autovacuuming turned on, although the
> application also vacuums on a schedule.
>

You might want to do a vacuum verbose on some of the suspect tables to see
how many dead tuples there actually are.

Sean