Verification of the search space exploration strategy based on the solutions of the join ordering problem

Abstract

The paper addresses the problem of quality estimation of the search space exploration strategy. The strategy is used to find a satisfying solution to the join ordering problem, which constitutes a crucial part of the database query optimization task. The method of strategy verification is based on the comparison of the execution time for the solution produced by the Invasive Weed Optimization (IWO) algorithm with the analogous value for the solution determined by the SQL Server 2008 optimizer. Solutions were generated for star queries that are common in data warehousing applications. The authors discuss representations of the single solution and describe the modified version of the IWO algorithm emphasizing features of the proposed hybrid method of the search space exploration. The results of the conducted experiments form the main topic of analysis. © 2011 Springer-Verlag Berlin Heidelberg.