计算机与现代化

• 数据库 • 上一篇    下一篇

计算SKY的预排序分组算法

  

  1.  
    (甘肃民族师范学院计算机科学系,甘肃 合作 747000)
  • 收稿日期:2013-06-14 出版日期:2014-02-14 发布日期:2014-02-14
  • 作者简介:刘萍(1978-),女,青海西宁人,甘肃民族师范学院计算机科学系讲师,硕士,研究方向:计算机算法与数据库。

 
Presorting Grouping Algorithm for Skyline Computation

  1.  
    (Department of Computer Science, Gansu Normal University for Nationalities, Hezuo 747000, China)
  • Received:2013-06-14 Online:2014-02-14 Published:2014-02-14

摘要: SFS算法的预排序思想基础上,借助数据集R上的单调分值函数,将R的点分组,提出计算Skyline的迭代算法。算法有效地支持用户的偏爱。给出证明:若R的点的个数为n,R的Skyline的点的个数为m,则在计算R的Skyline的过程中,需要对点之间所做的支配比较的次数不超过m(n-m/2-1/2);如果分组的组数为k,则分组算法比SFS减少比较次数不少于m(m-k)/2k。

关键词: 多元目标优化, 预排序, 轮廓, 分组算法

Abstract: In this paper, we proposed the presorting grouping algorithm for skyline computation. This algorithm was based on SFS algorithm, and efficiently supported the preference of users. We proved that, for computing skyline, the number required comparisons between two points does not exceed m(n-m/2-1/2), where n being the number of points, and m being the number of skyline points; if the number of groups being k, then the number required comparisons used in the presorting grouping algorithm reduced m(m-k)/2k.

Key words: multi-objective optimization, presorting, skyline, grouping algorithm

中图分类号: