> You can't yet... at least not with an ALTER statement. The only way to
> currenty do this is by dumping the table (through pg_dump),
> altering the type
> of the field, and then re-ipmorting the table.
>
> Rumor has it that they are working on an ALTER statement to
> accomplish this
> for 7.3 or 7.4.
Development currently stalled ;) Don't bet on it being there...
Chris