Pros and Cons of distributed data base management system

A distributed database is a network of database that are logically integrated but physically spread across a network. A distributed data base management system is software that controls the distributed database in the network. To make sure that the data in the distributed databases are also up to date and current, processes like duplication and replication.

Replication is the process by which software looks for the changes in the databases and updates the other one with the changes. At the end of the process both the databases would look the same with respect to data in it. Duplication on the other hand is different in that one of the databases would be the master and the other would be the slave. The data in the master is duplicated to the slave. In this the changes are made to the master database only.

 

There are advantages of using distributed databases. Usually it reflects your organization’s structure. Since the databases are spread across the network, it can be in each department so that the concerned department updates their database. Moreover in case of any catastrophic event, all the databases are not destroyed since they are distributed in different physical locations. The performance is also improved since the load is balanced on the servers. It costs less to have such a network instead of a single large computer. It is easy to add or remove systems without affecting the other modules.

 

On the downside, it is difficult to maintain such a network and there would be more load for the DBAs. Since the database is disconnected in nature, some extra work on the design part has to be done. Complexity is increase and labor costs would also increase. Since all the sites have to be secured it is an extra burden on that part. The manpower to manage such a database is rare to get. If you need to convert an existing centralized DB to a distributed one, there are no tools to do so. Concurrency control is an issue in distributed database.

 

You need to consider all these pros and cons before going for a distributed data base management system.