Hi, On 2018-12-19 19:39:33 -0500, Tom Lane wrote: > Robert Haas <robertmh...@gmail.com> writes: > > On Wed, Dec 19, 2018 at 5:37 PM Andres Freund <and...@anarazel.de> wrote: > >> What's gained by the logic of emitting that warning in VACUUM after a > >> crash? I don't really see any robustness advantages in it. > > > I don't know. I am just normally reluctant to change things > > precipitously that are of long tenure. > > Me too, but I think Andres has a point here. Those warnings in VACUUM > are ancient, probably predating the introduction of WAL :-(. At the > time there was good reason to be suspicious of zeroed pages in tables. > Now, though, we have (what we think is) a bulletproof crash recovery > procedure in which possibly-zeroed pages are to be expected; so we're > just causing users unnecessary alarm by warning about them. I think > it's reasonable to, if not remove the messages entirely, at least > downgrade them to a low DEBUG level.
Yea, I think that'd be reasonable. I think we ought to add them, as new/zero pages, to the FSM. If we did so both during vacuum and RelationAddExtraBlocks() we'd avoid the redundant writes, and avoid depending on heap layout in RelationAddExtraBlocks(). I wonder if it'd make sense to only log a DEBUG if there's no corresponding FSM entry. That'd obviously not be bulltproof, but it'd reduce the spammyness considerably. Greetings, Andres Freund
