There are three main features of a database management system that make it attractive to use a DBMS in preference to more conventional software. These features are centralized data management, data independence, and systems integration
In a database system, the data is managed by the DBMS and all access to the data is through the DBMS providing a key to effective data processing. This contrasts with conventional data processing systems where each application program has direct access to the data it reads or manipulates. In a conventional DP system, an organization is likely to have several files of related data that are processed by several different application programs.
If some major changes were to be made to the data, the application programs may need to be rewritten in CDPS. In a database system, the database management system provides the interface between the application programs and the data. When changes are made to the data representation, the metadata maintained by the DBMS is changed but the DBMS continues to provide data to application programs in the previously used way. The DBMS handles the task of transformation of data wherever necessary. This independence between the programs and the data is called data independence associated with DBMS.
In DBMS, all files are integrated into one system thus reducing redundancies and making data management more efficient. In addition, DBMS provides centralized control of the operational data on other hand CDPS does not carry this feature at this level of efficiency.
Redundancies and inconsistencies can be reduced in DBMS unlike CDPS.
A DBMS is often used to provide better service to the users. In conventional systems, availability of information is often poor since it normally is difficult to obtain information that the existing systems were not designed for.
Changes are often necessary to the contents of data stored in any system.