Re: [HACKERS] WIP: Aggregation push-down

From: Antonin Houska <ah(at)cybertec(dot)at>
Cc: pgsql-hackers(at)postgresql(dot)org
Subject: Re: [HACKERS] WIP: Aggregation push-down
Date: 2018-08-31 15:05:58
Message-ID: 18061.1535727958@localhost
Views: Raw Message | Whole Thread | Download mbox | Resend email
Lists: pgsql-hackers

Antonin Houska <ah(at)cybertec(dot)at> wrote:

> I've reworked the patch so that separate RelOptInfo is used for grouped
> relation. The attached patch is only the core part. Neither postgres_fdw
> changes nor the part that tries to avoid the final aggregation is included
> here. I'll add these when the patch does not seem to need another major rework.

This is the next version. After having posted a few notes to the [1] thread,
I'm returning to the original one so it can be referenced from my entry in the
CF application. As proposed in the other thread, it uses only "simple
aggregation". The 2-stage aggregation, which gives more power to the feature
and which also enables paralle processing for it, will be coded in a separate

I eventually decided abandon the Var substitution proposed by Heikki in
[2]. It's not necessary if we accept the restriction that the feature accepts
only simple column reference as grouping expression so far.



Antonin Houska
Cybertec Schönig & Schönig GmbH
Gröhrmühlgasse 26, A-2700 Wiener Neustadt

Attachment Content-Type Size
agg_pushdown_v8.tgz application/x-gzip 45.1 KB

In response to


Browse pgsql-hackers by date

  From Date Subject
Next Message Andres Freund 2018-08-31 15:07:03 Re: PostgreSQL logical decoder output plugin - unchanged toast data
Previous Message Tom Lane 2018-08-31 15:05:57 Re: remove ancient pre-dlopen dynloader code