The Translation of Object-Oriented Queries to Optimized Datalog Programs
Tore Risch · 1991
Copyright © 1991 Hewlett-Packard Company The advent of object-oriented DBMSs has created a demand for object-oriented (00) declarative query languages. Analogous to the relational en-vironments, the query processor has the responsibility of translating queries into efficient execution plans. In this paper we address the translation of queries in the OSQL language, which is the lingua franca of HP's IRIS system. The usefulness of the optimization of query execution cannot be understated based on the relational experience. We infer the need for certain optimization methods from the query con-structs and usage patterns that are particular to the 00 paradigm. Fur-ther, we observe the correspondence between the extensive optimization technology developed in the context of relational/Datalog queries and this new arena. Accordingly, we translate OSQL queries into optimized Data-log programs, wherein traditional optimization techniques can be utilized straightforwardly. This approach is demonstrated in a fully functional prototype implementa-tion of OSQL.