On 21.2.2015 02:00, Andrew Gierth wrote:
>>>>>> "Tomas" == Tomas Vondra <tomas.vondra@2ndquadrant.com> writes:
>
> >> Right...so don't test a datum sort case, since that isn't supported
> >> at all in the master branch. Your test case is invalid for that
> >> reason.
>
> Tomas> What do you mean by 'Datum sort case'?
>
> A case where the code path goes via tuplesort_begin_datum rather than
> tuplesort_begin_heap.
>
> Tomas> The test I was using is this:
>
> Tomas> select percentile_disc(0) within group (order by randnum) from stuff;
>
> Sorting single columns in aggregate calls uses the Datum sort path (in
> fact I think it's currently the only place that does).
>
> Do that test with _both_ the Datum and Numeric sort patches in place,
> and you will see the effect. With only the Numeric patch, the numeric
> abbrev code is not called.
D'oh! Thanks for the explanation.
--
Tomas Vondra http://www.2ndQuadrant.com/
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