On an algebra for historical relational databases: Two views

Abstract

In search of the appropriate semantics for the inclusion of structures and operations that will meet the needs of a wide class of users interested in a database system supporting temporal views of their data, the paper includes both a discussion of many problems that must be addressed, and a proposal for an extended relational algebra The informal dlscusslon of Issues motivates the proposal to time-stamp the attributes of relations, rather than the tuples The proposed algebra incorporates this view with a general treatment of non-first-normal-form relations. © 1985, ACM. All rights reserved.