Integrated Usage of Heterogeneous Databases for Novice Users

This paper proposes the system enabling users to use heterogeneous databases in an integrated manner without any conversion and servers. In order to treat a variety of sources in a unified manner, this system is realized by using Java Database Connectivity (JDBC) in accessing databases on the user´s computer. It also joins and/or projects them as required. The syntax identifying a kind of database or file is introduced. The system maintains data by using Array Lists in Java. It is experimentally shown that there is no practical problem in the equijoin of three tables having 100,000 rows in heterogeneous databases.