The Optimization Strategy for Query Evaluation in RDB/V1

RDB/V1 is a fully relational database managenent system that has been developed for end users. In implementing the system, we focused our efforts upon making the system easy to use and efficient in query evaluation. This paper deals with how to gain efficiency in query evaluation; that is, optimization of query evaluation. Our approach for optimization is a heuristic one. Some of the characteristics of our approach are: (1) access cost evaluation based on statistical data, (2) dynamic gathering of data for use in speeding up join operation, (3) integration of facility for optimization into the view mechanism, and (4) global optimization after local optimization.