Re: Range Types, discrete and/or continuous

On Mon, Oct 25, 2010 at 10:21:49AM -0400, Tom Lane wrote:
> David Fetter <david(at)fetter(dot)org> writes:
> > On Sun, Oct 24, 2010 at 06:59:34PM -0400, Tom Lane wrote:
> >> Put me in the camp that says you need both. I really seriously
> >> dislike the idea of representing [1, 2) as [1, 2-epsilon], mainly
> >> because there is often no portable value for epsilon.
> >> Dump-and-restore would be quite hazardous.
>
> > It wouldn't be stored as (1, 2-epsilon). It would be stored more
> > like (1, 2, closed, open).
>
> Fine ...
>
> > If you have a coherent, worked-out theory of continuous ranges,
> > please feel free to develop and publish it just as Snodgrass, et
> > al., have done with discrete ranges, but please *don't* feel free
> > to assume that you can just wave a magic wand and make continuous
> > time ranges "just work" because it pleases you aesthetically.
>
> That is FUD, and nothing more. If you know a concrete reason why
> Postgres shouldn't provide both closed and open ranges, you need to
> explain it, not claim that there might be a reason someplace and
> it's someone else's problem to prove your point for you.

That you're confusing the open/closed ranges with discrete/continuous
tells me that it's *you* who doesn't understand the issues at hand.

If you can present or develop a coherent theory of continuous ranges,
that's great. If you can present or develop a theory that merges that
one with discrete ranges, that's great too. Until then, let's get the
discrete ranges going and disallow ones based on the continuum, i.e.
floats.

Cheers,
David.
--
David Fetter <david(at)fetter(dot)org> http://fetter.org/
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