Richard Guo <guofenglinux(at)gmail(dot)com> writes:
> AFAICS, the Vars forced nonnullable by given clause are only used to
> check if we can reduce JOIN_LEFT to JOIN_ANTI, and it is checking the
> join's own quals there. It seems to me we do not need to pass down
> nonnullable_vars by upper quals to the children of a join.
Hmm, you are right, we are not doing anything useful with that data.
I can't remember if I had a concrete plan for doing something with it
or not, but we sure aren't using it now. So pushed.
regards, tom lane