Jeff Davis <pgsql@j-davis.com> writes:
> I tested in gdb, and it calls HeapTupleSatisfiesMVCC, until I VACUUM a
> few times, and then it doesn't call it any more. So, apparently the seq
> scan optimization _is_ there. And that means it is correctness-critical.
The page header bit is critical. Not the VM.
regards, tom lane
