中文摘要：

与因特网开发，在网上查询数据是包含信息从的一个注意问题分布式，并且经常动态地，相关的网来源。基本上，一些亚质问能有效地从以前的询问被缓冲或显形看以便基于重写询问的观点完成更好的询问表演。在这篇论文，我们建议一个新奇重写质问的模型，叫的层次质问树，为代表网询问。层次质问树是对在网上代表数据的固有的层次特征合适的一棵标记的树。基于层次质问树，我们使用 case-basedapproach 决定质问结果应该是什么。询问和质问结果的定义是把树标记两个都被代表。因此，我们能使用一样的模型代表盒子和中等质问结果能被用户询问动态地也更新。我们证明那个基于 ourcase 的方法能被用来基于以前的询问的联合回答新询问，包括干旱各种各样的信息采购的要求的变化。

英文摘要：

With the internet development, querying data on the Web is an attention problem of involving information from distributed, and often dynamically, related Web sources. Basically, some subqueries can be effectively cached from previous queries or materialized views in order to achieve a better query performance based on the notion of rewriting queries. In this paper, we propose a novel query-rewriting model, called Hierarchical Query Tree, for representing Web queries. Hierarchical Query Tree is a labeled tree that is suit able for representing the inherent hierarchy feature of data on the Web. Based on Hierarchical Query Tree, we use case based approach to determine what the query results should be. The definitions of queries and query results are both re presented as labeled trees. Thus, we can use the same model for representing cases and the medium query results can also be dynamically updated by the user queries. We show that our case-based method can be used to answer a new query based on the combination of previous queries, including changes of requirements and various information sources.