Lecture Notes on Software Engineering (LNSE)
Assertions are attracting attention recently for preventing programs from incorrect behavior. OCL is a logical description language included in UML. Assertions, although not usually implemented in a database, are implemented in the application program and executed in the test phase. They are commented out in the operation phase for performance. However, faulty data are possible to receive in open distributed systems such as Web application systems. Therefore, assertions must be implemented in the database as well as in the application program and executed in the operation phase.