"Matthew T. O'Connor" <matthew@zeut.net> writes:
> Peter Eisentraut wrote:
>> I'm not sure whether we can allow int8 columns in system tables, for
>> portability reasons.
> Someone will have to tell me if this is really a problem,
Depending on int8 to actually work is right out.
I'd go with float or double depending on your precision needs.
regards, tom lane