Re: patch: Distinguish between unique indexes and unique constraints - Mailing list pgsql-hackers

Robert Haas <robertmhaas@gmail.com> writes:
> You know, I've never really understood the difference between these
> two types of things, or why we need to support both.  Which may be
> just because I'm slow?

Unique constraints are defined by the SQL standard, and have a syntax
that can't support a lot of the extensions that CREATE INDEX allows.
There's also restrictions in the information_schema views.
So unifying the two concepts completely would be a mess.
        regards, tom lane