Re: Built-in binning functions

On Fri, Jun 13, 2014 at 8:22 PM, Petr Jelinek <petr(at)2ndquadrant(dot)com> wrote:
> here is a patch implementing varwidth_bucket (naming is up for discussion)
> function which does binning with variable bucket width. The use-cases are
> same as for width_bucket (=data analytics, mainly histograms), the
> difference is that width_bucket uses buckets of same width but the
> varwidth_bucket accepts an sorted array of right-bound thresholds to define
> the individual buckets.
>
> Currently applications implement this with long CASE statements which are
> quite hard to read/maintain and are much slower than this implementation
> which uses binary search.
>
> There are 3 actual functions, one generic and two faster versions for the
> int8 and float8 input that take advantage of the static width of those
> types.

I wonder if stuff like this shouldn't live in contrib rather than
core, but I guess it's probably not worth it for 3 functions.

--
Robert Haas
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