Re: Range types

On Mon, 2009-12-14 at 10:00 -0800, Nathan Boley wrote:
> IMHO the first question is whether, for integers, [1,2] UNION [3,5]
> should be equal to [1,5]. In math this is certainly true, and defining
> 'next' seems like a reasonable way to establish this in postgres.

[ you say "yes" ]

Agreed.

> The next question is whether, for floats, [1,3-FLT_EPSILON] UNION
> [3,5] should be [1,5].

[ you say "no" ]

I think this should be true, because all floats between 1 and 5 are
contained. I don't feel too strongly about this, so I would not complain
if floats were treated as continuous.

> And the next question is whether, for numeric(6,2), [1,2.99] UNION
> [3,5] should be [1,5].

[ you say "yes" ]

I almost agree. Unfortunately, typmod isn't really a part of the type,
it just affects input/output. So, we can't really use it that way -- as
Tom points out, typmod is not passed along to functions that take the
value.

But if it were a part of the type, then I would certainly agree.

Regards,
Jeff Davis