Why Distributed Database?
- Data are always available to end users, i.e., they are easily accessible. The availability makes the total system reliable.
- Distributed database increases the performance of the overall system. Because, the servers are available near the place where it is very much needed.
- Support organizational growth. Because, the distributed database structure would not cause stopping of all ongoing services. Only new distributed server may need to be established to handle the new details.
- Handling addition of any server, modification of existing modules etc. are easy.
- Distributed data handling increases the parallelism. That is, a number of queries can be handled simultaneously over multiple distributed server when compared to the central server approach.
The image shown below depicts the distributed server concept. It shows a set of DSs(Distributed Servers), a set of Nodes (not all are labeled), and a set of links which shows the request generated from node to the DS. The dashed line shows that the request generated by a node which is local to some other DS and the received DS forwarded to other DS where the intended data would be available. Here, the main advantage is consumption of network bandwidth is controlled, .i.e., network traffic reduced. Availability of the data and the server increased, as they are very close and accessible.