Study on Key Technology in Multidatabase System;

Considering current applications in CIMS, relational multidatabase system which has unique global schema is taken as the main part of global information system.

The features of transaction in multidatabase systems are analyzed, and the necessity to keep the global serializability when concurrency control of transaction processing in multidatabases is emphasized.

A method of schema mapping in multidatabase systems was introduced and an uniform formalized definition for horizontal, vertical, mixed, correlative and local mappings was given.

Schema integration is an important problem in multidatabase systems with a global schema.

The usage of object oriented technology to the schema integration problem of multidatabase systems is discussed.

A multi-database system was designed.

2) With the detail research works in the three methods: Data translating procedure, Middleware techniques and Multi-database systems, which can be used in the realization of integration of asynchronous structure database.

With the rapid development of information technology, in information integrated field, multi-database system is one of the effective methods that deal with information-exchange and integration among multiple heterogeneous date source.

Multidatabase Integrating Platform CMDatabase Architecture;

At the same time, the existing databases can not be discarded totally, so developing a multidatabase system that can access and process the data of multiple pre-existing databases is a necessary trend.