How can complex database queries be efficiently processed? This paper explores a strategy for processing multivariable queries in the INGRES database management system. The study focuses on decomposing queries into a sequence of one-variable queries, using reduction and tuple substitution techniques. The approach aims to simplify complex queries, making them more manageable and efficient to evaluate. Reduction involves breaking off components joined by a single variable. Tuple substitution involves substituting a tuple at a time for one of the variables. Algorithms are provided for both reduction and variable selection. Cost estimation procedures are developed to guide the decision of which variable to substitute. Overall, this research offers a valuable approach to query processing, particularly for multivariable queries. By decomposing complex queries into simpler components, the strategy aims to reduce the computational burden and improve performance. Future research may focus on refining the cost estimation procedures and evaluating the effectiveness of this approach in modern database systems.
As a discussion of query processing strategies in a database management system, this paper is a suitable fit for ACM Transactions on Database Systems. The journal often publishes articles on query optimization, database architecture, and techniques for improving database performance, all of which are relevant to the themes explored in this work.