An active database consists of a collection of event-condition-action rules (or ECA-rules), some meta rules that specify the desired interactions and constraints for the execution of rable rules, and a traditional database. The main goal of an active database is to automatically manage database operations. In general, the occurrence of an event can cause several rules to be rable nondeterminist...

The need for active capability for non-traditional applications and its concomitant bene ts are well-established. Although the event-based technique for monitoring conditions (leading to the integrated architecture) is the most versatile of all the techniques, from a practical viewpoint there is a need for enhancing pre-existing non-active DBMSs to support active capability. The set of techniqu...

We are currently developing an extensible interoperability toolkit called L'Heureux. Our toolkit supports integration mechanisms at various levels of semantics. The levels we have isolated so far are: database schemas, database transaction protocols, and application programs. To address some of the interoperability issues faced by L'Heureux's integration mechanisms, we are extending our toolkit...

A real-time database is a database in which both the data and the operations upon the data may have timing constraints. We have integrated real-time, object-oriented, semantic and active database approaches to develop a formal model called RTSORAC for real-time databases. This paper describes the components of the RTSORACmodel including objects, relationships, constraints, updates, and transact...

The expressiveness and complexity of several active database prototypes are formally studied. First, a generic framework for the spec-iication of active databases is developed. This factors out the common aspects of the prototypes considered, and allows studying various active database features independently of any speciic prototype. Furthermore, each of the prototypes can be speciied by specia...

This paper presents a system developed at unicamp for automatically maintaining topological constraints in a geographic database. This system is based on extending to spatial data the notion of standard integrity maintenance through active databases. Topological relations, deened by the user, are transformed into spatial integrity constraints, which are stored in the database as production rule...

Recent advances in non-monotonic semantics of deductive databases provide a simple framework for modeling the even-condition-action rules of active databases. This approach unifies the semantics of active and deductive databases and yields several benefits. In particular it can be used to model the semantics of different active databases and to perform termination analysis for active rules.