Recent progress in communication and database technologies has changed the data processing environment of users. The present data processing situation is characterized by a growing volume of applications that require access to various pre-existing local data sources located in heterogeneous hardware and software environments distributed among the nodes of a computer network.
The purpose of this thesis is to study an effective data sharing between heterogeneous relational database systems. Several methods of data sharing in a heterogeneous database environment were investigated and compared. Then, we propose a database gateway to overcome heterogeneity among relational database management systems(DBMS). A method is developed which translates commands in the language of a source DBMS to equivalent one of a target DBMS and also translates data from one format to another. We implement the database gateway with the above concepts. The gateway interfaces an ORACLE relational DBMS with a CODA relational DBMS on the SUN Sparc. The performance of the gateway is satisfactory for a wide range of test data and test queries.
