A STRUCTURED SPECIFICATION OF ALL ACTIVE DATABASE SYSTEM

Active database systems are a current focus of considerable research i nterest, as a means of supporting a range of tasks including constrain t enforcement, real-time applications and derived data management. How ever, although many different proposals have been made-for active rule systems, such proposals are normally described in an informal manner, which makes it difficult to understand how different proposals differ or how a set of rules will behave. This paper compares a range of for mal specification methods, considering how suitable they are for descr ibing active database functionality, and then shows how the model-base d notation Object-Z, an object-oriented extension of Z, can be used to specify the semantics of a representative active database system, nam ely Starburst.