Feasibility of Unified Usage of Heterogeneous Databases Storing Private Information

This paper shows the feasibility of the client-server retrieval system enabling users to receive various services with keeping the users' data private. This functionality is inevitable when the users want to receive some services while they want to keep their data private. In this system, the users could store their data into various kinds of database. It is shown that the system could be realized by using Java Database Connectivity (JDBC) in accessing databases in the client computers. The descriptions in using ordinary database management systems including PostgreSQL, MySQL, and SQLite are almost the same, while the description in using Excel files is slightly different from them.