Centerlised Database

A centralised database (sometimes abbreviated CDB) is a database that is located, stored, and maintained in a single location. This location is most often a central computer or database system, for example a desktop or server CPU, or a mainframe computer. In the traditional enterprise computing model, an Information Systems department use to maintain control of a centralized corporate database system. Mainframe computers, usually located at corporate headquarters, provided the required performance levels. Remote sites used to access the corporate database through wide-area networks (WANs) using applications provided by the Information Systems department. Changes in the corporate environment toward decentralized operations have prompted organizations to move toward distributed database systems that complement the new decentralized organization.

In centralized database architecture, data, application programs and DBMS is located in a mainframe system. An application program is used for taking inputs from users and displaying it to the screen. It also communicates with DBMS using SQL. It is used in DB2 and SQL/DS databases. When a user sends a SQL query from computer system, it is received by DBMS (database management system). Then the request is processed by the DBMS. It also communicates with the database to generate a result. After that it communicates with the application program and the result is displayed in the screen of the user..