Re: proposal: tuplestore, tuplesort aggregate functions

On Thu, Aug 19, 2010 at 12:45:13PM +0200, Pavel Stehule wrote:
> Hello
>
> > I'll test both variant first. Maybe there are not any significant
> > difference between them. Now nodeAgg can build, fill a tuplesort.
> > So I think is natural use it. It needs only one - skip a calling a
> > transident function and directly call final function with external
> > tuplesort. Minimally you don't need 2x same code.
>
> yesterday I did a small test. Aggregates without transident
> functions are only about 2% faster, so there has no sense thinking
> more about them. I'll send a patch with median and percentile
> functions immediately - these functions are implemented like usual
> aggregates.

NTILE is already a windowing function. Might want to check into any
performance improvements you can give that.

As to median, please make sure you say in detail which median you're
using and name it so, as there is no single, authoritative median.

Cheers,
David.
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