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计算机工程 ›› 2006, Vol. 32 ›› Issue (14): 49-50,6. doi: 10.3969/j.issn.1000-3428.2006.14.018

• 软件技术与数据库 • 上一篇    下一篇

演绎数据库中语义查询的动态优化算法

毛翼飞1;陶世群2   

  1. 1. 东北大学东软信息学院,大连 116023 2. 山西大学计算机科学系,太原 030006
  • 收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:2006-07-20 发布日期:2006-07-20

A Dynamic Optimization Algorithm of Semantic Query in Deductive Database

MAO Yifei1;TAO Shiqun2   

  1. 1. Neusoft Institute of Information, Northeast University, Dalian 116023; 2. Department of Computer Science, Shanxi University, Taiyuan 030006
  • Received:1900-01-01 Revised:1900-01-01 Online:2006-07-20 Published:2006-07-20

摘要: 演绎数据库的语义查询优化是利用数据库中的完整性约束,将用户提交的查询转换为与原查询等价且执行效率更高的查询规则。该文提出的动态语义优化算法在查询计算过程中动态约去存在的空展开式,使得查询时间开销的节省可用所除去的空展开式规模大小衡量,较适用于含有大量空展开式的演绎数据库。

关键词: 空展开式, 动态语义查询优化, 查询树

Abstract: Semantic query optimization in deductive database is based on integrity constraints to convert user’s query to another one that is the equivalence to the former and more efficient. This paper proposes the dynamic query optimization, which deletes the null expansions in the process of the query so that the cost can be simply measured by the scale of deleted these null expansions. In the field such as deductive database that has more null expansions, the dynamic query optimization algorithm shows more applicability.

Key words: Null expansions, Dynamic semantic query, Query tree