You can do it with a Universe SQL table (Make MV values unique, that is).
In traditional UV tables, however, you are correct. The uniqueness in this case is a combination of the primary key and the MV position.
I would also guess that the person in question was referring to multivalues since traditional MV tables (or Universe anyway) have no concept of a controlling attribute (or primary key) of an association.
Craig Bennett wrote:
David,
I just came out of a meeting where it was stated that MV databases allow non-unique keys.
perhaps the person was refering to multivalues?
If you were modelling parents and children in an SQL database you might use a PARENTS table and a CHILDREN table. Usually neither table would allow duplicate keys.
In MV you might have a PARENTS file which had a multivalued attribute CHILDREN. (I don't think) there is a way to make the database enforce a rule which makes all the children of a parent unique, except using triggers.
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