Re: BUG #17826: An assert failed in /src/backend/optimizer/util/var.c

David Rowley <dgrowleyml(at)gmail(dot)com> writes:
> On Fri, 10 Mar 2023 at 05:09, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> How is this even a little bit sane?

> I don't think it is. I've not looked in detail yet, but I think we
> might be able to do something in check_output_expressions() so that we
> track the targetIsInAllPartitionLists() separately. Maybe
> unsafeColumns[] needs to become an enum type that has UNSAFE, SAFE,
> WINDOW_RUNCONDITION_ONLY and then change things so we never make a
> runCondition when the qual is UNSAFE.

> Anyway, I'll give it more thought and aim to come up with a patch
> early next week.

Why can't we simply *remove* all this logic from subquery pushdown?

I would expect that what happens in useful cases is that we push down
the (safe) qual and then during planning of the subquery we see a WHERE
clause matching the window run condition and work with that. So this
all seems redundant, quite aside from being faulty.

regards, tom lane