Concepts of Database Management System

CHAPTER 2

Data Models and Architecture of DBMS

CHAPTER OBJECTIVES

• Evolution of data models.
• Knowing the traditional data models.
• Advantages and disadvantages of various types of data models.
• Three-level architecture of database management system.
• Understanding languages used to define objects, manage and control data and transaction.

2.1 EVOLUTION OF DATA MODELS

• Data are the primary requirement of any application. It is important to store data appropriately for easy access. During the 1940s and 1950s, use of computer to write applications in programming language for automation increased. The file-based management system was not sufficient to manage data. Hence, evolution of data models took place. Figure 2.1 shows the block diagram of evolution ...