Jack Orenstein <jao@geophile.com> writes:
> I guess the top-level question is this: Is it possible in principle for the
> btree index to subsume GIN index capabilities?
Well, you could write a completely different index AM that happened to
share the same on-disk representation, perhaps. But it would be a
different AM. btree is built for scalar values and has none of the
mechanisms that GIN does for breaking down input values into
components-to-be-indexed, nor for analyzing complex query operators
to find out what indexable search conditions are implied.
regards, tom lane