间隔查询作为重要的查询类型,广泛应用在社交网络、信息检索和数据库领域.为了支持高效的间隔查询,涌现出多种优化技术.尽管已有方法能够快速响应单个间隔查询,然而当查询负载超过服务器的处理能力时,70%的查询均不能在期望时间内得到响应.针对这一问题,提出采用共享执行策略优化间隔查询的方法 SESIQ(shared execution strategy for interval queries).SESIQ对间隔查询进行批处理,分析一组间隔查询间可共享的操作,减少重复数据的访问,从而降低磁盘I/O和网络传输代价,提高检索性能.理论分析并实验验证了SESIQ的可行性,基于两种真实数据集的大量实验结果表明,SESIQ是有效的,间隔查询的检索性能可提升数十倍.
As an important query type, interval query is widely used in social networks, information retrieval and database domain. Many kinds of optimization techniques have sprung up to support effective interval query. Although existing methods are efficient to handle single query, they all suffer from performance problem when the concurrent query loads exceed the processing capacity of the server such that more than 70% queries couldn't receive the results in the expected time. To solve this problem, this paper presents a method named SESIQ(shared execution strategy for interval queries). SESIQ batches interval queries, analyzes common operations among a group of interval queries and reduces duplicate data access to lower the cost of disk I/O and network transmission. The paper theoretically studies and analyzes SESIQ, and demonstrates the feasibility by large number of experiments based on two types of real datasets. Results show that SESIQ improves the performance of interval query by several ten folds.