Re: GROUPING SETS revisited

Hello

2010/8/3 Joshua Tolley <eggyknap(at)gmail(dot)com>:
> In case anyone's interested, I've taken the CTE-based grouping sets patch from
> [1] and made it apply to 9.1, attached. I haven't yet done things like checked
> it for whitespace consistency, style conformity, or anything else, but (tuits
> permitting) hope to figure out how it works and get it closer to commitability
> in some upcoming commitfest.
>
> I mention it here so that if someone else is working on it, we can avoid
> duplicated effort, and to see if a CTE-based grouping sets implementation is
> really the way we think we want to go.
>

I am plaing with it now :). I have a plan to replace CTE with similar
but explicit executor node. The main issue of existing patch was using
just transformation to CTE. I agree, so it isn't too much extensiable
in future. Now I am cleaning identifiers little bit. Any colaboration
is welcome.

My plan:
1) clean CTE patch
2) replace CTE with explicit executor node, but still based on tuplestore
3) when will be possible parallel processing based on hash agg - then
we don't need to use tuplestore

comments??

Regards

Pavel

> [1] http://archives.postgresql.org/pgsql-hackers/2009-05/msg00700.php
>
> --
> Joshua Tolley / eggyknap
> End Point Corporation
> http://www.endpoint.com
>
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