>Practically speaking there must be some level of scope where a duplicate name error can occur. All the docs say is that the schema >scope is not it. You've demonstrated that it is the table scope where duplication of names is detected.
Thanks, David. The sentence above is still misleading, at least according to my understanding.
Create a second table and add a constraint of the same name to it.
And your error is actually because the name of the unique index backing the constraint is a problem, not the name of the constraint itself. Try naming a check constraint.
David J.
As the rest of the paragraph explains, name duplication is checked at table level for all constraints and at schema level for index-based constraints (UNIQUE, PRIMARY KEY, EXCLUDE):
> > ... However, this extra freedom does not exist for index-based constraints (UNIQUE, PRIMARY KEY, and EXCLUDE constraints), because the associated index is named the same as the constraint, and index names must be unique across all relations within the same schema.
So, adding two index-based constraints (UNIQUE or PK or EXCLUDE) with same name fails, whether they are in the same table or different ones in the same schema.
Adding two constraints (whatever type) with same name in the same table fails.
Adding two or more constraints with same name in different tables of the same schema succeeds as long as none or only one is index-based.
