基于小生境遗传算法的SDD-1分布式查询优化算法

摘要

SDD-1 algorithm is a distributed query optimization algorithm,the genetic algorithm has been successfully ap-plied in many fields .In the SDD-1 algorithm based on genetic algorithm,genetic algorithm has a problem of“premature con-vergence”.To solve this problem,SDD-1 distributed query optimization algorithm based on niche genetic algorithm is pro-posed in this research.This algorithm can solve the query plan of minimum communication cost in possible time.Experimental results show that this algorithm has a better performance than SDD-1 algorithm and SDD-1 algorithm based on genetic algo-rithm.%SDD-1算法是一种分布式数据库的查询优化算法，遗传算法已经在许多领域得到了成功的应用。针对基于遗传算法的 SDD-1算法中，遗传算法存在“早熟收敛”的问题，提出一种基于小生境遗传算法的 SDD-1分布式查询优化算法，该算法能在尽可能短的时间内求解通信费用最小的查询计划。实验结果表明，该算法比单独使用 SDD-1算法、基于遗传算法的 SDD-1算法均有更优的性能。