On Thu, Apr 13, 2023 at 9:45 AM Robert Haas <robertmhaas@gmail.com> wrote:
>
> On Wed, Apr 12, 2023 at 4:23 PM Greg Stark <stark@mit.edu> wrote:
> > Am I crazy or is the parenthetical comment there exactly backwards? If
> > the horizon is *more recent* then fewer tuples are *non*-removable.
> > I.e. *more* tuples are removable, no?
>
> Isn't it the non-parenthetical part that's wrong? I would expect that
> if we don't know which relation it is, the horizon might be
> considerably LESS recent, which would result in fewer tuples being
> removable.
You can make arguments for either way of restating it being clearer
than the other.
Personally I think that the comment should explain what happens when
you pass NULL as your relation, rather than explaining what doesn't
happen (or does happen?) when you pass a non-NULL relation pointer.
That way the just-pass-NULL case can be addressed as the
possibly-aberrant case -- the possibly-sloppy approach. You're really
supposed to pass a non-NULL relation pointer if at all possible.
--
Peter Geoghegan