Abstract: Query sharing is an effective way to share the same or similar storage structures and query operations during the query procession so as to lessen the repetitive storage and resources occupation in a data stream system. For query storage sharing, a middle-result storage structure was designed, and accordingly an index-based algorithm with two-level indirect storage of the sharing queue was presented to enable the proper sharing of middle storage results, which can improve the flexibility for the data tuple to migrate as well. Meanwhile, for the multi-queries sharing, an algorithm to pick up the same query operations from several data streams was proposed, which can reduce the system processing resources by sharing the same processing resources in query operations. The model and algorithm were analyzed and discussed.

Key words: query optimization, CQL language, query tree

摘要： 为了提高查询效率，从数据流查询过程中查询操作单元和查询存储结构的共享两个方面展开研究。设计一种基于共享的二级索引队列，用于存储数据流中间结果。该结构使得中间查询结果可以再利用的同时也为数据共享情况下的迁移提供了一定的灵活性。对于多查询共享，通过抽取相同数据流中的相同谓词进行查询共享，实现一处计算多处使用的目的。最后对相关模型和算法进行了分析。

关键词: 查询优化, CQL语言, 查询树