分布式数据库的查询优化方法设计与实现软件工程专业毕业论文.docx

摘要
摘 要
文章对分布式数据库系统的基本概念进行了阐述,它包括分布式数据库的定义、分布式数据库系统的模式结构及体系结构,分布式数据库中的数据分片以及分布;接着简单对分布式查询处理与优化的一般过程进行了阐述;然后文章对经常用到的优化方法做了重点研究,如基于关系代数等价变换规则的优化算法、基于连接的优化算法、基于半连接的优化算法、SDD_1 算法。
文章主要是对分布式查询优化策略重点研究。文章的优化目标是以通信传输
开销为主,运用半联接运算这种算法,SDD_1 算法在分布式数据库查询中的运用做了大量的研讨,并探索出一个新的算法。是基于多关系半联接的优化算法,它适用于以分布式数据库系统的缓冲区作为查询的中间结果的最后装配站点这种情况。这种算法通过实验证明,很大的省去了中间环节的工作量,网络通信总代价得到了减低。
关键字:分布式数据库,查询优化,SDD_1,多关系半连接
Abstract
Abstract
The article has carried on the elaboration to the distributional database system's basic concept, it including definition and this system's pattern, architecture, in distributional database data lamination as well as distribution; Then simply processed the general process which to the distributional inquiry and optimized to carry on the elaboration; Then the article to the optimized method which used frequently has done the key research.
The article is mainly to the distributional inquiry optimization strategy key research. The article optimized goal is by corresponds the transmission expenses primarily, utilized half joint to operate this algorithm, the SDD_1 algorithm has made the massive deliberations in the distributional database inquiry utilization, and explored a new algorithm. Is based on relates half joint the optimized algorithm, this algorithm proved through the experiment, very big has omitted the middle link's work load, reduced its total price greatly for work service.
Keywords : distributional database , inquiry optimization , SDD_1 , relates half connection
目录
目 录
第一章绪 论................................................................................................................ 1
研究背景................................................................................................................. 1
国内外研究现状..................................................................................................... 2
本文的主要工作..................................................................................................... 2
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