Improved caching policies and hybrid strategy for query result cache

• Published in: 高技术通讯（英文版） Vol. 21; no. 3; pp. 339 - 346
• Main Author: Qian Libing Ji Zhenzhou Bai Jun
• Format: Journal Article
• Language: English
• Published: School of Computer Science and Technology, Harbin Institute of Technology, Harbin 150001, P.R.China 01.09.2015
• Subjects: 平均响应时间; 搜索引擎; 文档内容; 查询处理; 混合策略; 用户查询; 系统吞吐量; 缓存策略; caching policy; query result cache; query repeated distance; hybrid caching
• ISSN: 1006-6748
• DOI: 10.3772/j.issn.1006-6748.2015.03.015

To improve efficiency of search engines, the query result cache has drawn much attention re- cently. According to the query processing and user＇s query logs locality, a new hybrid result cache strategy which associates with caching heat and worth is proposed to compute cache score in accord- ance with cost-aware strategies. Exactly, query repeated distance and query length factor are utilized to improve the static result policy, and the dynamic policy is adjusted by the caching worth. The hy- brid result cache is implemented in term of the document content and document ids （docIds） se- quence. Based on a score format and the new hybrid structure, an initial algorithm and a new rou- ting algorithm are designed for result cache. Experiments＇ results show that the improved caching policies decrease the average response time effectively, and increase the system throughput signifi- cantly. By choosing comfortable combination of page cache and docIds cache, the new hybrid cac- hing strategy almost reduces more than 20% of the only cache and docId-only cache. average query time compared with the basic page-