Re: GROUPING SETS revisited

2010/8/3 Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>:
> 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

Couldn't you explain what exactly "explicit executor node"? I hope we
can share your image to develop it further than only transformation to
CTE.

Regards,

--
Hitoshi Harada