On Thu, 26 Apr 2001, Wendy wrote:
> I backed up a database at night and noted the size to be about over 300MB.
Backuped with pg_dump, or dumped the raw database files ? In the latter
case you want to stop the PostgreSQL server first.
> The following morning, I again backed up the same database and found out the
> size to be less than 100MB. There was no massive deletes by users during
> that morning.
If you dumped the raw database, this difference can be caused by VACUUM
being run automatically at night to free deleted items.
NB: personnally I recommend backuping using pg_dump or pg_dumpall. And
testing that restoration works.