| From: | David Rowley <dgrowley(at)gmail(dot)com> |
|---|---|
| To: | Simon Riggs <simon(at)2ndquadrant(dot)com> |
| Cc: | Kouhei Kaigai <kaigai(at)ak(dot)jp(dot)nec(dot)com>, Jim Nasby <Jim(dot)Nasby(at)bluetreble(dot)com>, David Rowley <dgrowleyml(at)gmail(dot)com>, Robert Haas <robertmhaas(at)gmail(dot)com>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, "pgsql-hackers(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: using custom scan nodes to prototype parallel sequential scan |
| Date: | 2014-11-17 19:08:13 |
| Message-ID: | CAHoyFK-4kb-OR2ukvibvi=X2GQZ=9_VsPTLrL2bE+B3r=n4a=w@mail.gmail.com |
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| Lists: | pgsql-hackers |
On 18 November 2014 05:19, Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:
> On 14 November 2014 11:02, Kouhei Kaigai <kaigai(at)ak(dot)jp(dot)nec(dot)com> wrote:
>
> > I'd like to throw community folks a question.
> > Did someone have a discussion to the challenge of aggregate push-down
> across
> > relations join in the past? It potentially reduces number of rows to be
> joined.
> > If we already had, I'd like to check up the discussion at that time.
>
> Yes, I was looking at aggregate pushdown. I think it needs the same
> changes to aggregates discussed upthread.
>
>
I have something that I've been working on locally. It's far from ready,
but it does work in very simple cases, and shows a nice performance boost.
I'll start another thread soon and copy you both in. Perhaps we can share
some ideas.
Regards
David Rowley
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