RDBMS : Benefit of Database Management System

A major advantage that the database approach has over the conventional approach is that a database management system provides centralized of data.

Following are some of the benefits of the database approach :

a. Redudancy is reduced : in the database approach, applications do not have to maintain their own data file. The same course data file is used by the course scheduling application, the instructor scheduling application, and the semester planning application.

b. Inconsistency is avoided : because redundancy is reduced, inconsistency is also avoided. Consider a situation where ten students have enrolled for a course. This information is stored in the student data file. The other applications will use the same student file and therefore, no inconsistency can occur. If this information is recorded in more than one place, inconsistency can occur, as changes made in one data file may not get reflected in another data file.

c. Data is shared : while the existing applications can share data in the database, new applications can also be developed that will use the same database.

d. Standards are enforced : with centralized control of data, the DBA can ensure that standards are maintained in stored data formats. This is particularly useful for data interchange, or migration of data between two systems.

e. Security restrictions are applied : the DBA eensures that only authorized persons have access to the database. The DBA defines the security checks to be carried out. Differenet checks can be applied to different operations on the same data. For instance, a person may have access to query a file, but may not have the right to delete or update that file.

f. Integrity is maintained : inconsistency between two entries can lead to integrity problems. Even without redundancy, the database can still be inconsistent. For example, a student enrolls in 10 courses when the maximum number of courses a student can enroll is seven. Or, a student enrolls in a course that is not being offered in that semester. Such problems can be avoided in a DBMS by establishing certain integrity checks that are performed with any update operation.

RDBMS : Introduction of DBMS

A database is a collection of records. One of the major tasks in a computer system is to store and manage data. To handle this task, you need a specialized computer software known as a database management system (DBMS). Database management systems are design to maintain large volumes of data. Management of data involves :

a. Defining structures for data storage
b. Providing mechanism for data manipulation
c. Providing data security against unauthorized access

Database management system are now available on a wide range of computer, from desktops to mainframes. The size and power of the computer determine the system facilities, such as security and storage.

A single-user system allows only one person to access a database at any given time. In a multi-user system, several users can access a database simultaneously.

With the increasing power of desktop computer, multi-user database systems are now available that support a small group of users to connect these desktop computers and access data concurrently. These database systems can be scaled up to support hundreds or thousands of users, depending on the configuration of the hardware on which the database system is running.

The main objectives of any DBMS are to :

a. Provide an efficient and convenient environment that is used to store data in, and retrieve data from a database.
b. Manage information about users who interact with the DBMS and the activities that these users can perform on the data.