Subquery Plan Reuse based Query Optimization (research paper)
Published in the 17th International Conference on Management of Data, COMAD, 2011
Abstract
In this paper, we revisit the problem of query optimization in relational DBMS. We propose a scheme to reduce the search space of Dynamic Programming based on reuse of query plans among similar subqueries. The method generates the cover set of similar subgraphs present in the query graph and allows their corresponding subqueries to share query plans among themselves in the search space. Numerous variants to this scheme have been developed for enhanced memory efficiency. Our implementation and experimental study in PostgreSQL show that one of the schemes is better suited to improve the performance of (Iterative) Dynamic Programming.