Framework design of a domain-key schema of a relational database

A new approach to the synthesis of the domain-key normal form (DK/NF) for an arbitrary domain is proposed. The Cartesian dependency, which is a special case of multivalued dependencies, is investigated. A lemma on the non-abnormality of a special relational and a theorem on the non-abnormality of the actual part of a relational framework are proved. A new criterion for determining the belonging of a database schema to DK/NF is given. The proposed approach can be used in designing information warehouse schemas.