数据流中的近似查询技术

近年来,一种密集型数据的应用得到了广泛的关注。在这种应用中,数据不再来自存储于永久介质的数据库,而是以大量的、连续的、快速的、随时间变化的、无边界的数据流的形式到达。本文深入研究数据流中的近似查询处理问题,针对数据流查询处理的典型特征,平衡内存有限性与查询结果精确性两大关系,综合多个著名系统关于近似查询处理的精髓思想,加以总结提出一系列如窗口查询、直方图、随机采样、小波等近似查询技术。

Technology of Approximate Query over Data Stream

Recently,a new class of data-intensive applications has become widely recognized,in which the data is modeled best not as persistent relations but rather as multiple,rapid,time-varying,in this paper,we deeply investigate about approximation query processing mechanism in data stream system. First of all,we consider seriously the typical characteristics of query processing in data stream system; secondly,we balance availably the finity of memory and accuracy of query result; then,we synthesize the quintessential ideas about approximate query processing of various famous data stream system; at last,we proposed a series of approximation query technologies according summarizing and analyses,such as Windows,Histograms,Random Sampling,Wavelets and the others summarization technologies.