How can we simplify database scheme design under the universal relation assumption? This paper proposes a simplified method for describing real-world database constraints using functional dependencies and a single join dependency. This alternative aims to address the limitations of existing methods when dealing with embedded multivalued dependencies. The relationship between this method and classical methods is explored, and the authors characterize multivalued dependencies in terms of hypergraphs. They also characterize join dependencies equivalent to sets of multivalued dependencies. This research offers a potentially more manageable approach to database scheme design under the universal relation assumption, potentially simplifying the modeling process and broadening the applicability of universal relation database design techniques.
Published in ACM Transactions on Database Systems, this theoretical work addresses fundamental issues in database design, aligning with the journal's focus on advances in database theory and technology. The proposed simplification of the universal relation assumption contributes to the journal's scope by offering a more practical approach to database schema design. The characterization of multivalued and join dependencies provides valuable insights for database researchers and practitioners.