Re: Range types

Tom Lane wrote:
> Martijn van Oosterhout <kleptog(at)svana(dot)org> writes:
>> However, it does seem reasonable to allow people to restrict, either by
>> typmod or a check constraint the kinds of values that can be stored in
>> a particular column. Then an application can decide which way they want
>> their intervals to work and have the database enforce it.
>
> Sure --- the range datatype should absolutely provide inquiry functions
> that let you determine all the properties of a range, so something like
> "CHECK (is_open_on_right(col))" would work for that. I'm of the opinion
> that we must not usurp typmod for range behavior --- the right thing is
> to pass that through to the contained type, just as we do with arrays.
>
> (Note that a range over timestamp(0) would eliminate at least some of
> the platform dependencies we've been arguing about. I'm still quite
> dubious that "next timestamp" is anything except evidence that you've
> misformulated your problem, though.)
>
> regards, tom lane

Well our work is based on over 15 years of temporal research (not by us)
and numerous books from Snodgrass, Date and Celko; as well as partial
implementations in other databases. So its not like we took a blue pill
this weekend and woke up with this hair-brained idea.

I understand your concern. But I think the objections are based more on
implementation details with float timestamp rather than conceptually.