摘要
通用异构数据源集成系统需要集成包括 WWW在内的各种数据源 ,有些数据源既无规则的模式结构 ,又无强有力的查询功能 ,给全局查询的分解和优化造成一定的困难 .异构数据源集成系统 Versatile一方面利用局部动态字典的模板操作构造集成系统全局动态字典 ,作为查询分解和优化的依据 .一方面采用基于缓存和数据源能力的查询分解和优化策略 ,以便充分利用数据源的查询能力 ,简化包装器的设计 ,并取得较高的查询效率 .
A heterogeneous data integration system can integrate a broad range of data sources including WWW. Decomposition and optimization for query are very difficult because some data sources have neither regular schemata nor strong query capabilities. To help query decomposition and optimization, a dynamic dictionary is proposed as unified schemata for various heterogeneous data sources, and the way for the construction of a global dynamic dictionary by operating on dynamic dictionaries of local data sources is given. Furthermore, to simplify the design of wrappers for data sources with limited capabilities and reduce responding time for query, an approach, which can take advantage of all powers of various data sources and results of prior queries, is proposed for query decomposition and optimization.
出处
《软件学报》
EI
CSCD
北大核心
2000年第2期222-228,共7页
Journal of Software
基金
国家自然科学基金
关键词
异构数据源
数据集成
查询分解
查询优化
数据库
Heterogeneous data source, data integration, dynamic dictionary, query decomposition, query optimization, query capability, cache.
