A data dictionary system approach for database schema translation

Database system reengineering technique has been used to resolve the problem of converting from existing out-of-data database systems to new technique database systems in order to reduce the new system implementation cost. The technique consists of three parts: schema translation, data conversion, and program translation. The schema translation requires the transferring of existing database schema into the new database schema with better semantics. Recapturing the semantics is a complicated and difficult work. During the database design phase, the semantics has been lost from the conceptual data model to the logical data model. It is difficult to recapture it. After recapturing the semantics from the original conceptual database schema, we also need to have a sophisticated knowledge base to store the knowledge. The paper describes a new schema translation system, which can recapture the missing/hidden semantics of a database. The kernel of the system is an extended entity relationship (EER) data dictionary system (DDS), which can store all the semantics of the new database schema.