Richard Huxton <dev(at)archonet(dot)com> writes:
> * Allow multiple unique constraints to share an index where one is a
> superset of the others' columns.
> That way you can mark it unique without having the overhead of multiple
> indexes.
That just moves the uncertain-dependency problem over one spot, ie, it's
the fabricated unique constraint that you can't pin down the
requirements for.
regards, tom lane