Re: upper planner path-ification

> -----Original Message-----
> From: pgsql-hackers-owner(at)postgresql(dot)org
> [mailto:pgsql-hackers-owner(at)postgresql(dot)org] On Behalf Of Robert Haas
> Sent: Tuesday, June 23, 2015 10:18 PM
> To: Kaigai Kouhei(海外 浩平)
> Cc: David Rowley; pgsql-hackers(at)postgresql(dot)org; Tom Lane
> Subject: Re: [HACKERS] upper planner path-ification
>
> On Tue, Jun 23, 2015 at 4:41 AM, Kouhei Kaigai <kaigai(at)ak(dot)jp(dot)nec(dot)com> wrote:
> > So, unless we don't find out a solution around planner, 2-phase aggregation is
> > like a curry without rice....
>
> Simon and I spoke with Tom about this upper planner path-ification
> problem at PGCon, and he indicated that he intended to work on it
> soon, and that we should bug him about it if he doesn't.
>
> I'm pleased to here this as I seem to have a special talent in that area.
>
It's fantastic support arm.

So, it may be more productive to pay my efforts for investigation
of David Rowley's patch, based on the assumption if we can add
partial/final-aggregation path node as if scan/join-paths.

My interest also stands on his infrastructure.
https://cs.uwaterloo.ca/research/tr/1993/46/file.pdf
It is a bit old paper but good starting point.

Thanks,
--
NEC Business Creation Division / PG-Strom Project
KaiGai Kohei <kaigai(at)ak(dot)jp(dot)nec(dot)com>