ACCESS TO INDEXED HIERARCHICAL DATABASES USING A RELATIONAL QUERY LANGUAGE

Abstract

This paper presents an efficient means to access indexed hierarchical databases using a relational query language. The purpose of this paper is an effective sharing of heterogeneous distributed databases. We investigate 1) translation of hierarchical data definition to an equivalent relational data definition, 2) translation of a relational query language statement to an equivalent program processable by a hierarchical database management system, and 3) automatic selection of secondary indexes of hierarchical databases. A major portion of the result has been implemented and the performance of the implemented system is analyzed. The performance of the system is satisfactory for a wide range of test data and test queries. It is shown that the utilization of the secondary index significantly enhances the efficiency in accessing hierarchical databases.