Understanding about Database

In our modern society most people know the term  database without understanding its full and clear meaning. Even in information technology circles, not

everyone knows the concepts in reasonable detail. What is a database? Is it data?

Is it software? Is it the place where you store data? Is there something special about

the way you store data? Is it how you store and retrieve data? What exactly is a

database system? What are the features and functions? Many more such questions

arise.

    Today, almost all organizations depend on their database systems for the crucial

information they need to run their business. In every industry across the board, from

retail chain stores to financial institutions, from manufacturing enterprises to government departments, and from airline companies to utility businesses, database

systems have become the norm for information storage and retrieval. Database

systems form the centerpiece of the growing and maturing electronic commerce.

Database and Web technologies have merged.

    The Information Technology department of today’s organization has a primary

responsibility: The department has to support and keep the database systems

running. In this transformed computing environment, knowledge of database

systems is no longer confined only to specialists such as data analysts and database

administrators. Are you are a systems analyst, programmer, project leader, or

network specialist? Then you also need to know the basics of database systems.

You also need to grasp the significance of the database approach. All IT professionals need to study the basic principles and techniques of database design and

development

(article from Database Design and Development: An Essential Guide for IT Professionals by Paulraj Ponniah
ISBN 0-471-21877-4 Copyright © 2003 by John Wiley and Sons, Inc.
3)

What is Database ?

• A database is a collection of non-redundant data which can be shared by different application systems

• 
  • stresses the importance of multiple applications, data sharing
  • the spatial database becomes a common resource for an agency
• implies separation of physical storage from use of the data by an application program, that is program or data independence
  • the user or programmer or application specialist need not know the details of how the data are stored
  • such details are "transparent to the user"
• changes can be made to data without affecting other components of the system. for example,
• change format of data items (real to integer, arithmetic operations)
• change file structure (reorganize data internally or change mode of access)
• relocate from one device to another, for example from optical to magnetic storage, from tape to disk