Optimization of Multi-Join Queries in Shared-Nothing Systems  

作　　者：Kian-Lee Tan(Department of Information Systems and Computer Science, National University ofSingapore, Lower Kent Ridge Road, Singapore 0511) 

出　　处：《Journal of Computer Science & Technology》1995年第2期149-162,共14页计算机科学技术学报（英文版）

摘　　要：This paper proposes a semi-greedy framework for optimizing multi-joinqueries in shared-nothing systems. The plan generated by the framework com-prises several pipelines, each performing several joins. The framework deter-mines the 'optimal' number of joins to be performed in each pipeline. Thedecisions are made based on the cost estimation of the entire processing plan.Two ekisting optimization algorithms are extended under the framework. Ananalytical model is presented and used to compare the quality of plans producedby each optimization algorithm. Our study shows that the new algorithms out-perform their counterparts that are not extended.This paper proposes a semi-greedy framework for optimizing multi-joinqueries in shared-nothing systems. The plan generated by the framework com-prises several pipelines, each performing several joins. The framework deter-mines the 'optimal' number of joins to be performed in each pipeline. Thedecisions are made based on the cost estimation of the entire processing plan.Two ekisting optimization algorithms are extended under the framework. Ananalytical model is presented and used to compare the quality of plans producedby each optimization algorithm. Our study shows that the new algorithms out-perform their counterparts that are not extended.

关 键 词：Multi-join optimization shared-nothing systems pipelining hash join segmented right-deep tree 

分 类 号：TN915[电子电信—通信与信息系统]