计算机应用 ›› 2011, Vol. 31 ›› Issue (03): 690-693.DOI: 10.3724/SP.J.1087.2011.00690

• 数据库技术 • 上一篇    下一篇

位置相关查询中基于最小访问代价的缓存替换方法

卢秉亮,梅义博,刘娜   

  1. 沈阳航空航天大学 计算机学院,沈阳110136
  • 收稿日期:2010-09-10 修回日期:2010-10-30 发布日期:2011-03-03 出版日期:2011-03-01
  • 通讯作者: 卢秉亮
  • 作者简介:卢秉亮(1953-),男(满族),辽宁本溪人,副教授,硕士,主要研究方向:数据库系统;梅义博(1982-),男,陕西山阳人,硕士研究生,主要研究方向:数据库系统;刘娜(1984-),女,山东泰安人,硕士研究生,主要研究方向:数据库系统。

Cache replacement method based on lowest access cost for location dependent query

LU Bing-liang,MEI Yi-bo,LIU Na   

  1. School of Computer, Shenyang Aerospace University, Shenyang Liaoning 110136, China
  • Received:2010-09-10 Revised:2010-10-30 Online:2011-03-03 Published:2011-03-01
  • Contact: LU Bing-liang

摘要: 在位置相关查询(LDQ)中由于用户的移动性和数据的位置相关性,给缓存替换策略带来了新的挑战。在详细分析位置相关数据(LDD)的空间位置特性和几种典型的位置相关缓存替换策略的基础上,提出一种基于最小访问代价的缓存替换策略(PLAC),一些重要的缓存替换因素如访问概率、更新频率、数据距离和有效范围等都包含在代价函数里,PLAC根据代价函数值的大小来决定被替换的数据,由此来保证有限缓存的最大使用率。通过实验对比,PLAC比其他位置相关缓存替换策略更为有效地提高了缓存命中率,缩短了查询平均响应时间。

关键词: 移动计算, 位置相关数据, 位置相关查询, 缓存替换

Abstract: Because of the user's mobility and the location dependency of data, new challenge has been brought to cache replacement strategy for Location Dependent Query (LDQ). Based on the detailed analysis of the space location characteristics of Location Dependent Data (LDD) and several typical replacement strategies of location dependent cache, the authors proposed a prioritized approach cache replacement based on the lowest access cost (PLAC), the PLAC took some important factors into account such as access probabilities, update rates, data distance, valid scope. To ensure the maximum utilization of limited cache, the PLAC cache replacement strategy decided which data would be replaced according to the value of the lowest cost function. The contrast experiments show that the PLAC increases cache hit rate and shortens query average response time more effectively than other location dependent cache replacement strategies.

Key words: mobile computing, Location Dependent Data (LDD), Location Dependent Query (LDQ), cache replacement

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