Chrono: A Conceptual Design Framework for Temporal Entities

Database applications are frequently faced with the necessity of representing time varying information and, particularly in the management of information systems, a few kinds of behavior in time can characterize a wide class of applications. A great amount of work in the area of temporal databases aiming at the de nition of standard representation and manipulation of time, mainly in relational database environment, has been presented in the last years. Nevertheless, conceptual design of databases with temporal aspects has not yet received su cient attention. The purpose of this paper is twofold: to propose a simple temporal treatment of information at the initial conceptual phase of database design; to show how the chosen temporal treatment can be exploited in time integrity enforcement by using standard DBMS tools, such as referential integrity and triggers. Furthermore, we present a design tool implementing our data model and constraint generation technique, obtained by extending a commercial design tool.