Active Object-Oriented Database Design Using Active Object/Behavior Diagrams

Active Object/Behavior Diagrams are introduced for the conceptual design of active object-oriented databases. They provide a high-level representation of active object-oriented database schemes such as ER-diagrams represent conventional database schemes. Object diagrams depict the structure of object types by a set of properties. Behavior diagrams depict the behavior of object types by a set of states and activities. A behavior diagram specifies which activities may be invoked on instances of an object type and gives necessary pre- and postconditions for activity invocations. Activation scripts specify the active behavior of object types. They define sufficient conditions for activities to occur using events and guards. Events specify when activities are performed. Guards determine the objects for which the activity is executed. During logical design properties of object diagrams are mapped into instance variables of object types, activities of behavior diagrams into methods, and activation scripts into Event-Condition-Action rules.