On Thu, Apr 13, 2023 at 9:45 AM Robert Haas <robertmh...@gmail.com> wrote: > > On Wed, Apr 12, 2023 at 4:23 PM Greg Stark <st...@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
