Re: range_agg

On 5/4/19 3:11 PM, Corey Huinker wrote:
> One question is how to aggregate ranges that would leave gaps and/or
> overlaps. So in my extension there is a one-param version that forbids
> gaps & overlaps, but I let you permit them by passing extra parameters,
> so the signature is:
>
>
> Perhaps a third way would be to allow and preserve the gaps.

Thanks for the feedback! I think this is what I'm doing already
(returning an array of ranges), but let me know if I'm misunderstanding.
My extension has these signatures:

range_agg(anyrange) returning anyrange
range_agg(anyrange, bool) returning anyarray
range_agg(anyrange, bool, bool) returning anyarray.

The first variant raises an error if there are gaps or overlaps and
always returns a single range, but the other two return an array of ranges.

I was planning to use the same signatures for my patch to pg, unless
someone thinks they should be different. But I'm starting to wonder if
they shouldn't *all* return arrays. I have two concrete use-cases for
these functions and they both require the array-returning versions. Is
it helpful to have a version that always returns a single range? Or
should I make them all consistent?

Thanks,

--
Paul ~{:-)
pj(at)illuminatedcomputing(dot)com