Re: Making Vars outer-join aware

On Fri, Dec 23, 2022 at 10:21 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Here's a new edition of this patch series.
>
> I shoved some preliminary refactoring into the 0001 patch,
> notably splitting deconstruct_jointree into two passes.
> 0002-0009 cover the same ground as they did before, though
> with some differences in detail. 0010-0012 are new work
> mostly aimed at removing kluges we no longer need.
>
> There are two big areas that I would still like to improve, but
> I think we've run out of time to address them in the v16 cycle:
>
> * It'd be nice to apply the regular EquivalenceClass deduction
> mechanisms to outer-join equalities, instead of the
> reconsider_outer_join_clauses kluge. I've made several stabs at that
> without much success. I think that the "join domain" framework added
> in 0012 is likely to provide a workable foundation, but some more
> effort is needed.
>
> * I really want to get rid of RestrictInfo.is_pushed_down and
> RINFO_IS_PUSHED_DOWN(), because those seem exceedingly awkward
> and squishy. I've not gotten far with finding a better
> replacement there, either.
>
> Despite the work being unfinished, I feel that this has moved us a
> long way towards outer-join handling being less of a jury-rigged
> affair.
>
> regards, tom lane
>
> Hi,
For v8-0012-invent-join-domains.patch, in `distribute_qual_to_rels`, it
seems that `pseudoconstant` and `root->hasPseudoConstantQuals` carry the
same value.
Can the variable `pseudoconstant` be omitted ?

Cheers