【摘要】 概括了基于视图的查询重写所涉及的研究领域,介绍了查询重写的一些基本概念和定理,总结了基于视图的查询重写的求解过程。在此基础上,揭示了使用视图重写查询过程中的两个独立复杂性因素,即包含映射和冗余基本式,分析了求解查询重写的复杂性问题。最后,结合当前流行的XML技术,讨论了XML领域中的查询重写问题及其与传统数据库中的查询重写问题的关系。更多还原

【Abstract】 The research fields involved by view-based query rewriting is generalized, and some foundational definitions and theorems on query rewriting is introduced. Furthermore the procedure of finding a view-based rewriting of a query is summarize. On the basis of these, It brings to light the two independent factors of the complexity of rewriting a query using views, namely containment mappings and redundant literals and analyzes the complexity problem of finding the minimal rewriting of a query. Finally, with the current popular technique-XML, the problem of query rewriting in the area of XML and the relation between it and the one in the area of traditional database is discussed.更多还原