Supporting dynamic displays using active rules

In a graphical interface which is used to display database objects, dynamic displays are updated automatically as modifications occur to the database objects being visualised. Approaches based on enlarging either the database system or the interface code to provide the appropriate communication, complicates the interaction between the two systems, as well as making later updates cumbersome. In this paper, an approach based on active rules is presented. The declarative and modular description of active rules enables active displays to be supported with minimal changes to the database or its graphical interface. Although this approach has been used to support the link between a database system and its graphical interface, it can easily be adapted to support dynamic interaction between an active database system and other external systems.