Re: BUG #17618: unnecessary filter column <> text even after adding index

On Tue, Nov 8, 2022 at 5:06 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Richard Guo <guofenglinux(at)gmail(dot)com> writes:
> > I've updated the patch according to the suggestions as in v4. Thanks
> > for reviewing this patch!
>
> I was about ready to commit this when I re-read your initial comment
> and realized that there's a second way to fix it. We can improve
> predtest.c so that it understands that "x = true" implies "x" and
> so on, whereupon the existing logic in create_bitmap_scan_plan
> handles the case correctly. This is pretty nearly the same code as
> in your v4, except that it's in a considerably less hot code path, plus
> there's at least some chance that it could be useful for other purposes.
> So I think I like this way better. Thoughts?

It works for me. predtest.c is a more common place so that there may be
other cases that can benefit from this change. Thanks for the new
patch!

Thanks
Richard