> On Jul 12, 2022, at 8:12 PM, MichaelDBA <MichaelDBA@xxxxxxxxxxx> wrote: > > Oh really? Even if it did an INDEX ONLY SCAN, it would still be slower because it still has to access the heap in a random I/O kinda way (like I said-->"The heap always gets accessed for select counts") because visibility info is only found in the HEAP not the index. This changed in 9.something. There is now a visibility map, which can, for data that hasn't changed recently, greatly reduce the amount of access required to the heap to determine visibility.
