Re: Range Types and extensions

On Sun, Jun 19, 2011 at 11:33:02PM -0700, Jeff Davis wrote:
> On Sun, 2011-06-19 at 21:29 +0200, Florian Pflug wrote:
> > If I'm not mistaken about this, that would imply that we also
> > cannot have two range types with the same base type, the same
> > opclass, but different collations. Which seems rather
> > unfortunate... In fact, if that's true, maybe restricing range
> > types to the database collation would be best...
>
> 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.
>
> A workaround is to use domains. That is effective, but awkward. For
> instance, given:
> CREATE DOMAIN textdomain AS text;
> CREATE TYPE textdomainrange AS RANGE (subtype=textdomain);
> then:
> '[a,z)'::textdomainrange @> 'b'::textdomain
> would work, but:
> '[a,z)'::textdomainrange @> 'b'
> would not, which would be annoying.
>
> I don't see a way around this. It's not a collation problem, but a
> general "multiple range types with the same subtype" problem.

How might you address that problem, assuming you had the needed
resources to do it?

Cheers,
David.
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