下载此文档

分布式数据库查询优化算法分析-软件工程专业毕业论文.docx


文档分类:IT计算机 | 页数:约62页 举报非法文档有奖
1/62
下载提示
  • 1.该资料是网友上传的,本站提供全文预览,预览什么样,下载就什么样。
  • 2.下载该文档所得收入归上传者、原创者。
  • 3.下载的文档,不会出现我们的网址水印。
1/62 下载此文档
文档列表 文档介绍
Abstract
join ,the optimization algorithm based on semi-join, the SDD_ 1 algorithm.
Finally, this paper based on the research of the query optimization algorithms of distributed database above, faced with the shortages of the SDD_1 algorithm (The selected gene is hard to estimate, and many assistant operations and so on), puts forward a new query optimization algorithm, for a while named by the multi-join queries based on two semi-join of distributed database. This algorithm avoids the shortages of the SDD_1 algorithm , introduces the two semi-join technique to
reduce entirely the joined cost between two stations ,and this bined by the algorithm of minimum spanning tree, gets the munication cost about the multi-join queries optimization and the assemble circs and the join order in the munication cost. According to the analysis of the algorithms’ examples, this algorithm has the similar query efficiency like the SDD_1 algorithm, and putation is not big .So in some special situations, this algorithm can almost replace the SDD_1 algorithm and get good query optimization effort.
Key words: distributed database; query optimization; SDD_1 algorithm; two semi-join; multi-join queries
分布式数据库查询优化算法研究
目录
摘 要............................................................................................................................ I
Abstract ......................................................................................................................... II
目录............................................................................................................................IV
第一章引 言..............................................................................................................1
论文背景........................................................................................................1
研究现状........................................................................................................3
本文主要研究内容......................

分布式数据库查询优化算法分析-软件工程专业毕业论文 来自淘豆网www.taodocs.com转载请标明出处.

相关文档 更多>>
非法内容举报中心
文档信息
  • 页数62
  • 收藏数0 收藏
  • 顶次数0
  • 上传人wz_198613
  • 文件大小224 KB
  • 时间2018-11-06