Re: Why does Postgres allow duplicate (FK) constraints

Tom Lane, 26.03.2013 17:03:
>> While I agree that this SQL should not have been written like this
>> in the first place, I wonder why Postgres doesn't actively prevent
>> this (like e.g. Oracle).
>
> If Oracle does that, they're violating the SQL standard --- there is
> nothing in the standard that supports rejecting an ALTER TABLE ADD
> CONSTRAINT on the grounds that it's redundant.  The spec only says
> you can't give two constraints the same name.

Is there anything in the standard that actively requires that you can create two "identical" constraints?

Because technically it simply doesn't make sense, does it?

Regards
Thomas