The Predicate Formulae for Object-Oriented Database Schema Evolution

Object-oriented database system is a superior model than relational database system, with schema evolution capacity. Although since the emergence of object-oriented database systems many schema evolution methods have been proposed, a complete formal description haven´t been formed. Therefore, it is necessary to use predicate logic to describe the operation of object-oriented database. This paper introduces predicate logic to illustrate schema evolution of object-oriented database with the predicate formulae. Atomic formulae and formulae are presented and the class evolution invariants and rules are also formalized.