I see INDF is rewritten to OR, and FilterRemoveIsNotDistinctFromRule rewrites INDF to CASE expression. Why do we want to do that? To simplify expression like "a is not distinct from b or a = b"? Then we spend a lot effort to convert OR/CASE back to INDF.
I am curious what is the motivation to rewrite INDF. Does it really help a lot in production? I would like to hear the use cases if it does. - Haisheng
