On 2017-12-07 17:41:56 -0300, Alvaro Herrera wrote:
> > > Looking at 0002: I agree with the stuff being done here. I think a
> > > couple of these checks could be moved one block outerwards in term of
> > > scope; I don't see any reason why the check should not apply in that
> > > case. I didn't catch any place missing additional checks.
> >
> > I think I largely put them into the inner blocks because they were
> > guaranteed to be reached in those case (the horizon has to be before the
> > cutoff etc), and that way additional branches are avoided.
>
> Hmm, it should be possible to call vacuum with a very low freeze_min_age
> (which sets a very recent relfrozenxid), then shortly thereafter call it
> with a large one, no? So it's not really guaranteed ...
Fair point!
- Andres