"Richard Neill" <rn214@cam.ac.uk> writes:
> * Convert a timestamp into a number of seconds since
> the epoch. This can be done in an ugly way using EXTRACT epoch FROM
> timestamp, but only to integer precision.
Uh, nonsense.
regression=# select extract(epoch from now());
date_part
------------------
1249884955.29859
(1 row)
It might've been like that back around 7.1, but not in any currently
supported version.
> * Division of a timestamp by an interval should result in something
> dimensionless.
This isn't a particularly sane thing to think about, because intervals
aren't single numbers.
regards, tom lane