MDM: Handling the Time Dimension in Generalized DBMS.

Abstract : The sense of time is implicit in almost all human activity, yet it is rarely reflected in the computer database views of these activities. This paper offers a method of dealing with time, modal storage and retrieval, and describes formal and practical realizations of the concept. The conceptual framework of Modal Data Management reflects three years of experience with the DATA (Dynamic Alerting Transaction Analysis) system, in which a time oriented DBMS has been conceived, designed and actually implemented. The paper first anchors the Modal Data Management concept in the context of the relevant research in Information Modelling and storage technologies, followed by a discussion of the architectural and functional attributes of the DATA system. The major lessons from the DATA experience are then presented, paying special emphasis to their impact on the design of future versions of the system. The concluding comments deal with specific implications of the Modal Data Management in the domains of DBMS usability and Software Engineering. (Author)