分布式知识系统中基于粗糙集合的查询策略研究

传统数据库中的数据查询通常忽视了对于知识的应用．随着网络技术的发展，数据被分布在不同的物理节点上，用户已不太可能对所有数据均有全面的了解．本文讨论了分布式知识系统中基于粗糙集合的查询策略，强调了系统中知识的重要性．它可大大地降低网络节点间的通信代价，从而提高查询效率．粗糙集合理论的应用使得查询不必局限于传统的精确匹配式查询，而可以是一种粗糙、模糊匹配式的查询．

RESEARCH ON ROUGH SET BASED QUERY STRATEGY IN DISTRIBUTED KNOWLEDGE SYSTEM

It has usually ignored the usage of knowledge when querying data in a traditional database. By the rapid development of network, data are distributed to different physical sites. It is almost impossible for the users to know the data wholly in such complicated cases. In this paper, we present a rough set-based query strategy in a distributed knowledge system and concentrate on the role of knowledge. It can reduce the communication costs among the different sites of network, and enhance the query efficiency accordingly. Rough set theory makes the query rough or fuzzy, not being precise as in the conventional case.