Hi Dilip,
Recently I was thinking about this too, when working on the index-only
count(*) patch for indexes supporting amgetbitmap [1]. That patch
teaches bitmap heap scan node to skip heap fetches under certain
conditions. Exact tidbitmap pages are a prerequisite for this, so the
lossines
|Hello everyone,
I made a new patch according to the previous comments. It is simpler
now, only adding a few checks to the bitmap heap scan node. When the
target list for the bitmap heap scan is empty, and there is no filter,
and the bitmap page generated by the index scan is exact, and the
