On the Representation of Temporal Dynamics

Abstract

Research in temporal database management has suggested that the Entity-Relationship model must be extended to compensate for its lack of constructs for representing the world’s dynamic nature. This claimed deficiency arises from the mistaken idea that Entity-Relationship diagrams represent only a snapshot of reality. Practitioners have long used Entity-Relationship diagrams without temporal extensions to design systems with rich support for temporality by using entities to represent the events that cause state changes, rather than by defining temporal attributes and relationships to record past states. While both approaches can represent temporality, only the event approach maintains modeling parsimony and represents why a particular state exists.