Research On Heterogeneous Database Query Based On XML

With the development of Internet and database, in the company information development and manage, heterogeneous database's application more and more. So people brought share with heterogeneous database information. It is a lot of relevant sets of database systems to construct the heterogeneous database. It can realize sharing of data and transparent ness for visit. Each database system in join the heterogeneous database itself already existed and has its own DBMS. Each part of the heterogeneous database has its own autonomy quality. At the time of realizing the data sharing, Each database system have its own application characteristic, the integrality control and the security control still.The merits and characteristic of XML--it has nothing to do with the platform, easy to expand, its intersection is good ,sometime have stronger quantity, and it can be formatted--make it easier to describe the heterogeneous database and realize the inter-convert between heterogeneous database. Besides, through its own merits, it can solve the problems--the deficient of union inquiries about and optimizes, the integration of heterogeneous database share based on WEB is not very mature, poor expanding --existing in heterogeneous database system at present partly.This paper consider heterogeneous database integration architecture, we chose the Three-tier network architecture as a framework for heterogeneous data integration platform architecture. Thesis will be applied to XML data integration technology to design XML-based framework for data integration platform, give the architecture of the framework of the implementation strategy for each module. Middle layer with xml data as a descriptive tool, through the mapping relationship between the various heterogeneous database xml converted to a unified format, as Xquery query language used to provide users with tools and a unified query interface. Based on XML technology to achieve many of the heterogeneous model of the proposed database query, to the programmer provides a train of thought to resolve this problem, improve the reusability of the process, reducing the cost of software development in order to more reasonable and more effective solution to heterogeneous multi-database data extraction and sharing of the problem.