Research On XML-Based Data Integration System Framework And Query Rewriting

Due to high-speed development of computer technology and e-business, the volumes and types of information that an enterprise can access have increased greatly in recent years. Because of the requirement of enterprise application and Web data integration, the research on data integration under Web environment is very flourishing. Owing to the advantage of the XML: extensible, structured and platform independent merits, XML has become to be the standard of data exchange on Internet quickly, which leads to a hot research topic on XML-based data integration today. It is an ideal solution to data integration.In this paper, the problem of the XML-based semistructured data integration is addressed. Firstly, this paper introduces the XML and its related technology, the knowledge and the constraints of semistructured data; Secondly, the fundamental knowledge of the data integration is researched on. Such as: integration system theoretical framework, basic mapping scheme, query operation of the integration system and so on. Then on the basis of the above research, a data integration system framework that based XML is designed. This system makes use of a unified XML view to integrate and query heterogeneous data source. Because taking full advantage of virtue of the XML data model, this system has fairly good extensibility. Finally, we research on the basic algorithm of the query rewriting, then a novel algorithm is explored to make use of constraints. This algorithm enhance the expressive ability of materialized view in the mediator layer by the equivalent transformation of queries and merge related information from multiple sources by using global constrains. According to the semantics of global query answering, we explain and prove this algorithm by examples.