On The Representation Of Temporal Dynamics

Abstract

Research in temporal database management has suggested that the EntityRelationship 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. 701 E. Chocolate Avenue, Hershey PA 17033-1240, USA Tel: 717/533-8845; Fax 717/533-8661; URL-http://www.idea-group.com IDEA GR UP PUBLISHING This chapter appears in the b ok, Advanced Topics in Database Research, edited by Keng Siau. Copyright © 2003, Idea Gr up Inc. Copying or distri uting in print or electronic forms without written permission of Idea Group Inc. is prohibited.