| 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. |
| 关键词: 异构数据源,数据集成,动态字典,查询分解,查询优化,查询能力,缓存. |
| DOI： |
| 分类号: |
| 基金项目:本文研究得到国家自然科学基金资助. |
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| Query Decomposition and Optimization in Heterogeneous Data Integration System |
|
WANG Ning,WANG Neng-bin
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| Abstract: |
| 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. |
| Key words: Heterogeneous data source,data integration,dynamic dictionary,query decomposition,query optimization,query capability,cache. |
