Events Specification In Active DatabaseManagement System

Abstract

Active Databases Management System have been objective of countless researches in the last years. Its active functionalities, as well as the concept of active objects or events are used in several application areas, not only in technology of databases. However, there is not a clearly defined notion distinguishing systems considered actives of the non actives. However, certain essential characteristics are requested for the elaboration of these active functionalities, as EGA rules definition, events specification, production rules, and others. The present paper goals to give a generic view of one of those mentioned characteristics that I consider to be one of the most fundamental topics for the elaboration of active systems, that is the events specification. Starting from a solid and concise specification of the concerning events to a certain application, the elaboration of a efficient rules execution model for an active database management system is possible. This way, it will be given a general vision of the EGA rules, the event concept, its relationships, its types and classifications, and the pertinent operators to the events algebra. The establishment's necessity of the conditions that leads the events specification will be exposed, the definition of the executed actions when of the occurrence of events and the conditions validation, approached inside of the concept of the production rules. Transactions on Information and Communications Technologies vol 19 © 1998 WIT Press, www.witpress.com, ISSN 1743-3517