Processing hierarchical queries in heterogeneous environment

The authors investigate principles of translating relational queries to hierarchical queries. Instead of using a specific hierarchical database system they abstract a generic hierarchical database system (GHDBS) which has properties common to database systems whose schema contain hierarchical structures. Principles of query translation with GHDBS as the receiving database system are developed. Rules that guarantee the correctness of the translated queries are described. Rules are provided that can guarantee a minimum number of target queries in a case when a user-submitted source query needs to be translated to multiple target queries