Web仓储中视图变化频率的自适应估测.pdfVIP

ISSN 1000-9825, CODEN RUXUEW E-mail: jos@ Journal of Software, Vol.18, No.2, February 2007, pp .303−310 http://www.j DOI: 10. 1360/jos1 80303 Tel/Fax : +86-10 © 2007 by Journal of Software. All rights reserved. ∗ Web 仓储中视图变化频率的自适应估测 1+ 1 2 2 张 岩 , 唐世渭 , 杨冬青 , 李晓明 1(视觉与听觉信息处理国家重点实验室(北京大学),北京 100871) 2(北京大学 计算机科学技术系,北京 100871) Self-Adaptive Estimation of View Change Frequency in Web Warehouses 1+ 1 2 2 ZHANG Yan , TANG Shi-Wei , YANG Dong-Qing , LI Xiao-Ming 1(State Key Laboratory on Machine Perception (Peking University), Beijing 100871, China) 2(Department of Computer Science and Technology, Peking University, Beijing 100871, China) + Corresponding author: Phn: +86-10 E-mail: zhy@, /teacher/system/zhangyan/ Zhang Y, Tang SW, Yang DQ, Li XM. Self-Adaptive estimation of view change frequency in Web warehouses. Journal of Software, 2007,18(2):303−310. /1000-9825/18/303.htm Abstract: Refreshing materialized views is a main task of Web warehouse maintenance. As the refreshing scheme depends heavily on the base data change frequency, researchers have presented many corresponding algorithms and frequency estimators for it. Although these estimators really work, however, all of them have limitations. The bias that an estimator introduces will increase significantly when the estimated value is out of its applicable range. In this paper, a self-adaptive algorithm is presented based on Poisson process analysis, which can adjust the revisiting pattern and revisiting frequency according to the estimated change frequency. This algorit