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Jovita Kaur, Lovely Professional University Unit 4: Database

Notes
Unit 4: Database

CONTENTS
Objectives
Introduction
4.1 Concept of Database
4.2 Evolution of Database and DBMS Technology
4.3 General-Purpose of DBMS
4.4 Database Approach
4.5 Summary
4.6 Keywords
4.7 Review Questions
4.8 Further Readings

Objectives
After studying this unit, you will be able to:
Discuss the concept of database
Describe about the evolution of database and DBMS technology
Explain the general-purpose DBMS.

Introduction

A database is an organized collection of data for one or more purposes, usually in digital form. The
data are typically organized to model relevant aspects of reality (for example, the availability of
rooms in hotels), in a way that supports processes requiring this information (for example, finding
a hotel with vacancies).

Notes The term “database” refers to logical and physical materialization of its data, content,
in files, computer memory, and computer data storage.
This definition is very general, and is independent of the technology used. However, not every
collection of data is a database; the term database implies that the data is managed to some level
of quality (measured in terms of accuracy, availability, usability, and resilience) and this in turn
often implies the use of a general-purpose Database management system (DBMS). A general-
purpose DBMS is typically a complex software system that meets many usage requirements, and
the databases that it maintains are often large and complex.
The term database is correctly applied to the data and data structures, and not to the DBMS which is
a software system used to manage the data. The structure of a database is generally too complex to
be handled without its DBMS, and any attempt to do otherwise is very likely to result in database
corruption. DBMSs are packaged as computer software products. Well-known products include
the Oracle DBMS, Access and SQL Server from Microsoft, DB2 from IBM and the Open source DBMS
MySQL. Each such DBMS product currently supports many thousands of databases all over the
world. The stored data in a database is not generally portable across different DBMS, but can inter-
operate to some degree (while each DBMS type controls a database of its own database type) using
standards like SQL and ODBC. A successful general-purpose of DBMS is designed in such a way that
it can satisfy as many different applications and application designers as possible. A DBMS also needs
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