| The rapid development of electronic commerce has become one of world mainstream industries in today's world; e-commerce is gradually changing the way people live. However, various enterprise systems have many differences in the network structure, hardware and software platform, system structure, especially in database systems, leading to difficult to implement data exchanging between enterprises and enterprises, enterprises and third-party systems, thus hampering the Electronic business development seriously.This dissertation presents and implements a unified view based on virtual data integration solutions in order to address the above problems.the objective is to make business and business or departments within the enterprise can share the resources to address the problem of information silos because of the heterogeneous data, thus improving the overall application performance and using resources effectively.In view of the above solution, the author propose a three-layer data integration architecture containing Mediator.In this dissertation we have mainly studied the key technologies on data integration such as the establishment of a global view, global query decomposition, the merger of each sub-query results .About the global query decomposition, we propose a new solution, the decomposition for the whole select statement, making the query more easier and function more powerful. We also conducted in-depth research on results merger, presented in combination with XQuery, XSLT technology. Finally, this dissertation presents the design and implementation of the key part. The main contents of this study are as as-follows:(1) The establishment of a unified virtual view.This section focus on the registration center's design, local view's establishment, data dictionary's establishment, the table relates, as well as how to form the overall situation table and several other aspects of the study.(2) The decomposition of global query. The dissertation presents more advantages of using global query-based SQL statements than query-based XQuery expressions, and then proposed the global query decomposition algorithm based on SQL select statement.(3) Local query processing. This section focuses on the packaging of the query results and the conversion algorithm of SQL select statement to the XQuery FLWOR expression when the data source is XML file. In addition, we also introduce the query queue scheduling and query performance optimization techniques briefly.(4) The query results merger. This dissertation first gives the combined strategy of query results, and then based on this strategy, we discuss on how to build global XQuery expressions and XSLT processing of documents detailedly.(5) The system design and realization of the key modules.This section first gives three-tier construction for data integration, then explains the systems operation flow and finally presents the implementation of its essential parts. |
