DBMS and its Applications

DBMS:

A database management system is a software system. It allows access to the data in a database. It consists of a set of interrelated data together with a set of programs to access those data.

Objective:

The objective of a DBMS is to provide a convenient and effective method of defining, storing and retrieving the data in the database.

Purpose of DBMS:

Before the arrival of DBMS, data were processed using file processing system. File processing system consists of several application programs and each application program has its own data stored in private files. In this system the same data file cannot be shared. Hence duplication of data is required if two or more application programs have to share the same data.

Disadvantage of file processing system:

The file processing system has the following major disadvantages:

• Data redundancy and inconsistency.
• Integrity Problems.
• Security Problems
• Difficulty in accessing data.
• Data isolation.

a) Data redundancy and inconsistency:

Data redundancy means duplication of data and inconsistency means that the duplicated values are different.

b) Integrity problems:

Data integrity means that the data values in the data base should be accurate in the sense that the value must satisfy some rules.

c) Security Problem:

Data security means prevention of data accession by unauthorized users.

d) Difficulty in accessing data:

Difficulty in accessing data arises whenever there is no application program for a specific task.

e) Data isolation:

This problem arises due to the scattering of data in various files with various formats. Due to the above disadvantages of the earlier data processing system, the necessity for an effective data processing system arises. Only at that time the concept of DBMS emerges for the rescue of a large number of organizations.

Data base system applications:

Universities: For student information, course details, and grades.

Airlines: For reservations and schedule information.

Credit card transactions: For purchase on credit cards and generations of monthly statements.

Human resources: For information about employees, salaries, payroll taxes, benefits and for generations of paychecks.

Banking: For customer information, accounts, and banking transactions.