Re: Remove an unnecessary check on semijoin_target_ok() on postgres_fdw.c

Alexander Korotkov <aekorotkov(at)gmail(dot)com> 于2025年3月25日周二 18:57写道：

> On Fri, Nov 29, 2024 at 3:39 AM Tender Wang <tndrwang(at)gmail(dot)com> wrote:
> > Alexander Pyhalov <a(dot)pyhalov(at)postgrespro(dot)ru> 于2024年11月29日周五 00:02写道：
> >>
> >> Tender Wang писал(а) 2024-10-09 10:26:
> >> > Hi,
> >> > When I debug FDW join pushdown codes, I found below codes in
> >> > semijoin_target_ok():
> >> > if (bms_is_member(var->varno, innerrel->relids) &&
> >> >
> >> > !bms_is_member(var->varno, outerrel->relids))
> >> >
> >> > As far as I know, if a var belongs to the innerrel of joinrel, it's
> >> > not possible that it
> >> > may belong to the outerrel. So if the bms_is_member(var->varno,
> >> > innerrel->relids)
> >> > returns TRUE, then !bms_is_member(var->varno, outerrel->relids) must
> >> > be TRUE.
> >> > If bms_is_member(var->varno, innerrel->relids) returns FALSE,
> >> > !bms_is_member(var->varno, outerrel->relids) will not execute due to
> >> > short circuit.
> >> >
> >> > So I think we can remove the "!bms_is_member(var->varno,
> >> > outerrel->relids)" from if.
> >> > Any thoughts?
> >>
> >> Hi.
> >> Seems good to me.
> >> --
> >> Best regards,
> >> Alexander Pyhalov,
> >> Postgres Professional
> >
> >
> > Thanks for looking at that.
>
> Pushed. But I've decided to keep the redundant check as an assertion.
>

Thanks for pushing.

--
Thanks,
Tender Wang