Re: issue about information_schema REFERENTIAL_CONSTRAINTS

Robert Haas <robertmhaas@gmail.com> writes:
> On Tue, Aug 31, 2010 at 10:46 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> We are not going to try to enforce uniqueness.  This has been debated
>> before, and most people like the current behavior just fine, or at least
>> better than the alternatives.

> Really?  I thought the issue was that no one had figured out how to do
> it, or that no one had written the patch, not that anyone thought the
> current behavior was particularly desirable.  What happens if you say
> ALTER TABLE .. DROP CONSTRAINT or COMMENT ON CONSTRAINT?  You just
> pick one at random?

No, because those syntaxes constrain the choice to one single
constraint.  Perhaps if the SQL committee had designed 'em,
there'd be an issue; but they are Postgres-isms.

            regards, tom lane