"Matthew T. O'Connor" <matthew@zeut.net> writes:
> It is fairly easy to implement, however it has been discussed before and
> decided that it wasn't necessary. What the system cares about is how
> long it's been since the last vacuum in terms of XIDs not time.
I think Alvaro is intending to do the latter (store per-table vacuum xid
info) for 8.2.
regards, tom lane