James Robinson <jlrobins(at)socialserve(dot)com> writes:
> Given a table with a pair of any sort of line-segment-esqe range
> delimiter columns, is it possible to build a unique index to enforce
> non-overlapping ranges?
Nope, sorry. Unique indexes enforce non-equality, but there's no way
to pretend that "overlaps" is an equality condition (hint: it's not
transitive).
I don't say that it'd be impossible to construct an index type that
could do this, but you won't get there with the pieces we have.
regards, tom lane