Robert Haas <robertmhaas@gmail.com> writes:
> On Mon, Jun 20, 2011 at 2:33 AM, Jeff Davis <pgsql@j-davis.com> wrote:
>> Yes, we cannot have two range types with the same base type. That is a
>> consequence of the polymorphic type system, which needs to be able to
>> determine the range type given the base type.
> Boy, that's an unfortunate limitation. :-(
Given the need to deal with multiple collations for collatable types,
I'd say it's not so much "unfortunate" as "utterly unworkable". At
least unless you give up the notion of binding the collation into the
type definition ... which has other issues, per discussion a few days
ago. Even ignoring collations, I really think we want to allow multiple
range types for base types that have multiple btree sort orderings.
regards, tom lane