Research And Implementation Of Distributed Heterogeneous Database Integration And Transparent Access

With the development of computer technology and communication network and the rapid diffusion of all kinds of application, many different units have established a large number of data management system. However, due to various reasons, these data management platforms were running on different operating systems, using different database systems and had no unified data format plan, It is not conducive to the exchange and sharing of data. In the digital simulation platform of high-speed trains, there are also a large number of heterogeneous data and different database system, there are a lot of database tables that distributed in different locations and generated, managed and used by different units. How to integrate data in each system and provide transparent data access for users, how to achieve data sharing in the digital simulation platform of high-speed trains has become an urgent problem.For this reason and combined with the actual needs of the digital simulation platform of high-speed trains, this thesis studied the distributed heterogeneous database integration and transparent access problems. First, we analyzed the advantage and disadvantage of the existing data integration methods, designed and implemented a new kind of integration of heterogeneous data access system after considered the actual needs. The system is based on the middleware technology and virtual database strategy, It is a typical three-tier architecture, between the upper user and the underlying database, there is the virtual database that built by semi-structured XML technology and cross-platform Java technology. The virtual database provides data queries for users and run all the interfaces for databases, so that the integration and transparent access to heterogeneous database can be accomplished.Secondly, this thesis plans and designs each module in the distributed heterogeneous database integration transparent access system, describes every important details of the design and implementation of the core module, mainly including data source registration module, user registration module, query processing module and query results processing module. The system uses the JDBC database connection technology to connect and access databases, and uses the dom4j technology to parse XML files. The using of Java Swing technology is to provide a friendly access query interface.Finally, the correctness and validity of the thesis ideas and technical methods is verified by functional testing. The system has been proved by its users that it has configuration flexibility, good compatibility and easy to transplant. It provide a valuable reference for future engineering...