Temporal databases

Abstract

This article presents a Temporal Enhanced Entity-Relationship (TEER) model, which shows how temporal information can be captured within a conceptual data model and extended to the relational data model. The time elements proposed for the TEER model include both transaction time and valid time. In order to support time-related queries, the query language SQL has been extended for definition, retrieval, and control of historical relations. For the commercialization of temporal databases, several technical and non-technical issues need to be resolved. This article provides a discussion of these issues and evaluates its progress toward commercialization.