Remote Data Based On The Oracle Distributed Database Maintenance And Security

Along with the development of the society and the computer technologies, the storage of data information can not get away from the sustainment of database system. The database system of Oracle has powerful abilities for data management which talent showing itself. Now the application of Oracle database has been widely introduced into broad areas, and particularly in most systems for the electronic commerce and electronic governmental affairs. Therefore I raised such an issue as the maintenance and safety research of remote data based on Oracle Distributed Database, and did some researches on this topic to certain extension and implements some key technologies, for better system development hereafter.The key technologies, in my research, include how to organize and implement "Multi-Layered" structures, how to achieve "Work Flow" in "Office Automatization", how to implement the technology on the information communion, encryption and protection, the technology on business guidance and audit, and the technology on the information protection and sharing. This article starts with and dissertate these key technologies such as Middle Component, multimedia large object, connection and snap shop of database, data transactions of distributed databases, data security issue in distributed databases, data backup and recovery of databases and data audit in detail. The discussion would be done combining with some practical projects and previously developed systems from the software engineering point of view and achieve research results which had been applied and validated in the projects and systems.In the practical project, we adopt the Oracle Middle Layer Service 9ias to implement multi-layer structures. We described the Oracel9iAS system construction in the treatise, and the strengthened safety characteristic of the Database Connection by using EJB; We discovered the specialty on Multimedia Large Object through the maintenance on it, found that it is implemented by adopting PL/SQL process in the Oracle DBMS_LOB package and stored its encrypted data form in the database. In ourdevelopment process, we usually met with the problem with data synchronous in distributed databases. To solve this, we adopted the snap shot function provided by the Oracle database. It is essential for distributed databases to have backup and recovery functions to ensure it is properly running, though they are only be invoked when problems occur in database. The database's safety issue is not cognized as much important as operating system's. However, in case of the datum in the database involved some business secret information, once they were stolen, the potential loss would be considerable. Therefore, I aimed at this phenomenon to bring up a research in my thesis according to the data safety in Oracle database and provided practical solutions which have been implemented in the developed system.The maintenance and safety on remote data of Oracle Distributed Database are every important and realistic problem. All examples in my article are tested in Oracle 8i 8.1.7, Oracel9i 9.2.0.4 and Oracel9iAS, and verified in the developing projects and systems.