Robert Haas <robertmhaas@gmail.com> writes:
> I'm starting to think that the right thing to do here is to create a
> non-lossy option for TIDBitmap. Tom has been advocating just losing
> the index scan AM altogether, but that risks losing performance in
> cases where a LIMIT would have stopped the scan well prior to
> completion.
Actually, I'm going to *insist* that we lose the index AM scan
altogether. There might be a possibility to put it back in 8.5 or later
if anyone actually makes the case (with some evidence) that it's worth
the trouble. But right now, what this patch needs is to be made to work
reliably, and having a great deal of complexity added by an inessential
feature is a good way to make sure it doesn't go in at all.
regards, tom lane