On Wed, Apr 2, 2025 at 12:08 PM Andres Freund <andres@anarazel.de> wrote:
> > It isn't at all rare for the scan to have to return about 1350 TIDs
> > from a page, though. Any low cardinality index will tend to have
> > almost that many TIDs to return on any page that only stores
> > duplicates. And scan will necessarily have to return all of the TIDs
> > from such a page, if it has to return any.
>
> I'm not sure what you're arguing for/against here? Obviously we need to handle
> that case. I doubt that the overhead of once-per-scan allocation of a
> MaxTIDsPerBTreePage * sizeof(BTScanPosItem) array once per scan matters when
> that many tuples are returned.
I'm not arguing for or against anything. I'm just giving context.
--
Peter Geoghegan
