Denotational Semantics for an Active Rule Execution Model

In the last few years, many active database models have been proposed. Some of them have been implemented as research prototypes. The use and study of these prototypes shows that it is difficult to get a clear idea of the proposed approaches and to compare them. More generally there are some unquestionable difficulties in understanding, reasoning about and teaching behavior of active database systems. We think there is a need for formal descriptions of the semantics of such systems in order to describe and to understand them with less ambiguities, to compare them and to come up with some progress in defining standard concepts and functionalities for active databases.