Re: Missing optimization when filters are applied after window functions

Volker Grabsch <vog@notjusthosting.com> writes:
> I propose the following general optimization: If all window
> functions are partitioned by the same first field (here: id),
> then any filter on that field should be executed before
> WindowAgg.

I'm not sure if that rule is correct in detail, but in any case the
short answer is that window aggregates are a new feature in Postgres
and we basically haven't done any optimization work on them yet.
Feel free to work in that area if it interests you...
        regards, tom lane