关键词: 查询优化, CQL语言, 查询树

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