The Implementation Of Distributed Database Management

Along with the extensive application of distributed system, distributed database system(DDBS) has become an important field of information processing. DDBS eliminate many disadvantages of conventional centralized database system, suit many non-centralized architecture. DDBS is a set of data, which belong to a single system logically, but in fact these data are distributed in many sites. DDBS has the advantages of data sharing, high reliability and availability, high query speed, and etc. In the distributed database system, to achieve high query speed and high availability, data redundancy is the necessary measure. But because the data are copied from lots of web sites, once you want to update these duplicates, to guarantee the consistency of the database, you must make the same modification for these duplicates at the same time.