Conceptual treatment of multivalued dependencies

Abstract

Multivalued dependencies are considered to be difficult to teach, to handle and to model. This observation is true if multivalued dependencies are treated in the classical approach. We introduce another treatment of multivalued dependencies based on ER modeling techniques and show that multivalued dependenices can be handled in a more natural and intuitive way within our framework. Based on the concept of competing multivalued dependencies we can prove in which case a unique ER schema representation exists. If multivalued dependencies are competing then either one of the competing schemata is chosen or an approximation which combines the competing schemata can be used. © Springer-Verlag Berlin Heidelberg 2003.