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计算机工程 ›› 2008, Vol. 34 ›› Issue (3): 105-107. doi: 10.3969/j.issn.1000-3428.2008.03.037

• 软件技术与数据库 • 上一篇    下一篇

特征数据距离连接的选择性估计

高 钰,刘国华   

  1. (燕山大学信息科学与工程学院,秦皇岛 066004)
  • 收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:2008-02-05 发布日期:2008-02-05

Selectivity Estimation of Characteristic Data Spatial Join

GAO Yu, LIU Guo-hua   

  1. (College of Information Science and Engineering, Yanshan University, Qinhuangdao 066004)
  • Received:1900-01-01 Revised:1900-01-01 Online:2008-02-05 Published:2008-02-05

摘要: 选择性估计是设计空间数据库查询优化器的基础。该文利用空间对象的MBR缓冲区和线段缓冲区,根据数据集在空间连接时的特点和特征数据的分布规律,提出了一种基于点缓冲区的选择性估计方法,用于特征数据的距离连接选择性估计。实验证明,该方法能较好地应用于特征数据的距离连接选择性估计中,较为准确地对特征线段集的距离连接作出估计,明显减少特征数据在估计时的相对误差。

关键词: 空间数据, 选择性估计, 点缓冲区

Abstract: Selectivity Estimation is the base of spatial database query optimizer. This paper uses MBR buffer area and line segment buffer area of spatial object, according to the characteristics of data set in spatial join and distributed law of characteristic data, putting forward a selectivity estimation method based on point buffer area, which is used in spatial join selectivity estimation of characteristic data. Experiment proves that the method does well in use of the spatial join selectivity estimation of characteristic data and decreases the relative error clearly when characteristic data are estimated.

Key words: spatial data, selectivity estimation, point buffer area

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