Re: Rethinking representation of partial-aggregate steps

Tom Lane wrote:

> What I'm imagining is, say,
>
> #define AGGOP_COMBINESTATES 0x1
> #define AGGOP_SERIALIZESTATES 0x2
> #define AGGOP_DESERIALIZESTATES 0x4
> #define AGGOP_FINALIZEAGGS 0x8
>
> typedef enum AggPartialMode
> {
> AGGPARTIAL_SIMPLE = AGGOP_FINALIZEAGGS,
> AGGPARTIAL_PARTIAL = AGGOP_SERIALIZESTATES,
> AGGPARTIAL_FINAL = AGGOP_COMBINESTATES | AGGOP_DESERIALIZESTATES | AGGOP_FINALIZEAGGS
> } AggPartialMode;
>
> #define DO_AGGPARTIAL_COMBINE(apm) (((apm) & AGGOP_COMBINESTATES) != 0)
> #define DO_AGGPARTIAL_SERIALIZE(apm) (((apm) & AGGOP_SERIALIZESTATES) != 0)
> #define DO_AGGPARTIAL_DESERIALIZE(apm) (((apm) & AGGOP_DESERIALIZESTATES) != 0)
> #define DO_AGGPARTIAL_FINALIZE(apm) (((apm) & AGGOP_FINALIZEAGGS) != 0)
>
>
> These enum constants satisfy the properties I mentioned before, but their
> assigned values are chosen to make the macros cheap.

Ah, sure, that makes sense.

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Álvaro Herrera http://www.2ndQuadrant.com/
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