A few misc. questions.

Hi all,

I have a few miscellaneous questions. If anyone has any ideas I'd
appreciate hearing them.

1. What happens when the primary key index runs out. That is, if we use an
INT(4) for a key and we create and delete enough to reach that number then
what happens?

2. Does anyone one know a standard SQL method (that works with Postgres) to
retrieve the primary key of a newly INSERTed record? We've found one way but
it will not work with order databases since it relies on reading data from
the sequence tables.

3. Does anyone know of any way to perform a database backup/synchronization
that somehow does its work when the database is otherwise not busy? Which is
preferred, backing up the PG files or doing some sort of sync?

4. Does anyone have any advice on how often to run VACUUM? Any rules of
thumb, etc?

Thanks,

--Rainer