>> What it sounds like to me is that you're not vacuuming the system
>> catalogs, which are getting bloated with dead rows about all those
>> dropped tables.
>>
>
> Wow, great!
>
> It is not immediately clear from the documentation, but the VACUUM
> command also deals with the system catalogs as well, correct?
>
>
To expand on Tom's answer, rows in system tables are created not only
for tables but for each column in the table, rules, indexes, etc. You
can end up with a lot more row creation than you suspect. And temporary
tables bloat the system tables just like regular tables. We discovered
that cron scripts using temporary tables can cause very rapid
system-table blotage.
Cheers,
Steve