TEMPORAL DATABASES

This paper summarizes the major concepts, approaches, and implementation strategies that have been generated over the last fifteen years of research into data base management system support for time-varying information. We first examine the time domain, its structure, dimensionality, indeterminacy, and representation. We then discuss how facts may be associated with time, and consider data modeling and representational issues. We survey the many temporal query languages that have been proposed. Finally, we examine the impact to each of the components of a DBMS of adding temporal support, focusing on query optimization and evaluation.