• Table of Contents

Chapter 1 Databases and Database Users

Introduction

Let’s begin by defining what is a database? Essentially, you can think of it as a collection of related data.

Figure 1.1 A database that stores student and course information**.**

In context, data can be in various formats such as numbers, text, and others. For example, the student names, course number, year, and etc. So it now begs the question of how do we specify the different data types in our database and manage the data?

Database Management System

A DBMS is a general-purpose software system that facilitates the processes of defining, constructing, manipulating, and sharing databases among various users and applications:

• Defining a database involves specifying the data types, structures, and constraints of the data to be stored in the database.
• Constructing the database is the process of storing the data on some storage medium that is controlled by the DBMS.
• Manipulating a database includes functions such as querying the database to retrieve specific data, updating the database

For this course, we will be using Oracle.

Figure 1.2 A simplified database environment**.**

The database and DBMS software form together what we call a database system.

Chapter 2 Database System Concepts and Architecture

We begin by discussing the data models and defining the concepts of schemas and instances, which will be fundamental to the study of database systems.

Data Models

A data model is a collection of concepts that can be used to describe the structure of a database. They can be categorize as shown:

• High-level or conceptual data models provide concepts that are close to the way many users perceive data.