Alvaro Herrera <alvherre@alvh.no-ip.org> writes:
> Hmm, yeah, sounds useful. There's one implementation issue to notice
> however, and it's that the autovacuum process dies and restarts for each
> iteration, so there's no way for it to remember previous state unless
> it's saved somewhere permanent, as the stats info is.
I think you'd really need to remember the previous oldest XID on a
per-table basis to get full traction out of the idea. But weren't we
thinking of tracking something isomorphic to this for purposes of
minimizing anti-wraparound VACUUMs?
regards, tom lane