On Wed, Apr 2, 2025 at 12:08 PM Andres Freund <and...@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
