Developing an active heterogeneous database system

The heterogeneous environment is emerging in current information systems. Within this situation, it is desirable to maintain consistency across databases, i.e., to ensure that they do not contradict each other with respect to the existence or value of a real-world entity. Active rules have been widely used in modern database systems. Active databases contain the capability to automatically monitor the conditions which are defined over the database state and the ability to take an action when the state of the underlying database changes. They have provided a great contribution to the maintenance of data integrity and data consistency in database systems. This paper investigates how to integrate active rules into a heterogeneous database system environment