Gain insights into fundamental database concepts, relational databases, and entity-relationship diagrams. Learn about normalization techniques and basics of SQL to enhance database efficiency.

Databases are universal - they underlie the technology you use every day. They're a crucial component of everything from telecommunications systems, banking systems, and video games to just about any other software system that maintains some amount of persistent data.

In this course, you'll learn about the fundamental concepts of databases, why and when they're used, what relational databases are, and entity-relationship diagrams. You will also be exposed to techniques like normalization that help to increase the efficiency of databases. You'll wrap up with a look at the basics of Structured Query Language (SQL). 

After completing this course, you will be able to move onto more advanced courses involving database systems and SQL.

Database Design Fundamentals for Software Engineers

# Characteristics of a database

Several characteristics distinguish the database approach from the file-based system. These include:

## 1. Self-describing nature of a database system

A database system is self-describing because it not only contains the database itself, but also the **meta-data** which defines and describes the data and relationships between tables in the database. This information is stored in a catalog by the DBMS software. The separation of data and information about the data makes the database system different from the traditional file-based system in which the data definition is part of the application programs.

Let's consider the university database example in the previous lesson. The DBMS catalog will store the definitions of all the tables in that database. The figure below shows part of the database catalog:

**Tables**
| Table_name    |  Number_columns   |
| --- | --- |
|  Student   |  3   |
|  Course    |  3   |
|  Department    |  2   |
| Instructor |  3  |


**Columns**
|  Attributes    |  Datatype   |  Belongs_to   |
| --- | --- | --- |
|  ID   |  Integer (4)   |  Student   |
|  First_Name   | Character (50)    |  Student   |
|  Last_Name   | Character (50)    |  Student   |
|  Course_name   | Character (50)    | Course   |
|  Course_Section   | Integer (4)    | Course   |
|  Department_Name   | Character (50)    | Department   |
| ...   | ...|  ...  |

In this lesson we will discuss the characteristics of a database.

Introduction

Fundamental Concepts

Data Modeling

Entity-Relationship Data Model

The Relational Data Model

Functional Dependencies

Normalization

Structured Query Language

Conclusion

Characteristics of the Database Approach