Research On Some Key Technologies In Virtual Database

The growing popularity of the network, as well as distributed computing technology continues to evolve and widely used to speed up the process of human information. Enterprises of different industries in the information construction process, due to the development of the different time or development department, often multiple information systems running on different hardware and software platforms running at the same time, these information systems according to the different needs of different data organization mode, so as to form a variety of mutual isolation mutually independent heterogeneous data sources, making the data difficult to communicate between systems, the sharing and integration, thus forming the "islands of information". With the deepening of the application of information technology within the enterprise, corporate and external information exchange needs increasingly strong and urgent need to integrate existing information, Unicom "islands of information" to share information.Data integration is one of the main ways to solve the problem of the "islands of information" through data-level integration level, the sharing of data between different applications. The virtual database technology is a new type of data integration technology distributed heterogeneous autonomous data sources is logically integrated, and thus provide a unified view of the data, so users can transparently these heterogeneous The data source access and management.First this review of the course of development of data integration technology, summarized and research and has a variety of data integration technology, and then leads to the virtual database, new data integration technology, and for a brief analysis of the technology. Second chapter on the basis of the analysis of heterogeneous and autonomous data source, given the design goals of the system, and then propose a comprehensive integrated technical merits of the various other data virtual database architecture and function module to do a more detailed analysis and elaboration. The third chapter discusses some of the key technologies of the system, first introduced query optimization techniques, basic principles and processes from the virtual database query to query optimization algorithms, and the connection between the sub-query results and their interaction operator the composition of the global query Pictured basis of the proposed algorithm is a combination of the MST-SO and SR-DO algorithm advantage of the cost-based query optimization algorithm, and the algorithm is applied to the query process; then describes the event-based model data monitoring and synchronization technology, focuses on the log analysis techniques, and discusses the implementation strategy of the event-based model; Finally, on the basis of analysis of the distributed transaction proposed a global transaction agent-based model, and discusses the global transaction local affairs agency, concurrency control and global deadlocks implementation strategies. The fourth chapter is a brief analysis cited above key technical performance testing of a prototype system and test data. Chapter V of the contents of this article are summarized, and the deficiency of this article and in the future need to continue to improve and the contents of the study.