On Mon, Dec 2, 2024 at 12:02 PM Tom Lane <t...@sss.pgh.pa.us> wrote: > Andres Freund <and...@anarazel.de> writes: > > I think the problematic scenario involves tuples that *nobody* can see. > > During > > the bitmap index scan we don't know that though. Thus the tid gets inserted > > into the bitmap. Then, before we visit the heap, a concurrent vacuum removes > > the tuple from the indexes and then the heap and marks the page as > > all-visible, as the deleted row version has been removed. > > Yup. I am saying that that qualifies as too-aggressive setting of the > all-visible bit. I'm not sure what rule we should adopt instead of > the current one, but I'd much rather slow down page freezing than > institute new page locking rules.
Freezing a page, and setting a page all-visible are orthogonal. Nothing has changed about when or how we set pages all-visible in a long time -- VACUUM has always done that to the maximum extent that its OldestXmin cutoff will allow. (The changes to freezing made freezing work a little bit more like that, the general idea being to batch-up work.) -- Peter Geoghegan
