A database management system is an integrated set of software programs that provides various applications of DBMS all the necessary capabilities for building and maintaining database files, extracting the information required for making decisions and formatting the information into structured reports.
It is intended to:
- Make data independent of the applications programs being used, so that it is easy to access and change. For example, you create a student database with many student records. After some time, you decide to change the structure of the student database to include phone numbers. With a DBMS you can do this and still use the application program you were using before you changed the database structure. This is possible because the data’s organization is independent of the program being used.
- Establish relationships among records in different files. The user can obtain all data related to important data fields. For example, the user can obtain student name and address information from the student file at the same time as viewing the student’s course information (course numbers and names) form the registration file because each file has the student’s social security number (data field) in it.
- Minimize data redundancy. Because data is independent of the application program being used, most data needs t be stored only once. For example, the student data file can be accessed by both the billing application program or the student grade averaging program.
- Define the characteristics of the data. Databases can be created that have data stored in them based on particular informational needs.
- Manage file security.
- Maintain data integrity. Because data redundancy is minimized, file updating is made easier and data consistency is improved. The DBMS ensures that updates are properly done.
Using DBMS software, users can request that a program be run to produce information in a predefined format or extract information in a specific way. The easiest way to view a DBMS is to think of it as a layer of software that surrounds the database files. The DBMS software usually includes a query language, report writers, and utilities. Newer DBMS programs also offer graphics capabilities that make it even easier for users to run the program and graphically enhance the appearance of output reports-both hardcopy and softcopy.