Database Design

Introduction

Database Design is the step by step process of producing a detailed Data Model of a Database. This Logical Data Model contains all the needed Logical and Physical Design choices and physical storage parameters needed to generate a design in a Data Definition Language, which can then be used to create a Database. A fully attributed Data Model contains detailed attributes for each entity.

The term Database Design can be used to describe many different parts of the design of an overall Database System. Principally, and most correctly, it can be thought of as the Logical Design of the base Data Structures used to store the data. In the Relational Model these are the Tables and Views. In an Object Database the entities and relationships map directly to object classes and named relationships. However, the term Database Design could also be used to apply to the overall process of designing, not just the base Data Structures, but also the forms and queries used as part of the overall Database application within the Database Management System (DBMS).

The process of doing Database Design generally consists of a number of steps which will be carried out by the database designer. Usually, the designer must:

• Determine the relationships between the different data elements.
• To add as a distinct feature, element, or quality a logical structure upon the data on the basis of these relationships.
  
  
  
  
  
  DATABASE DESIGN BASICS :

A properly designed database provides you with access to up-to-date, accurate information. Because a correct design is essential to achieving your goals in working with a database, investing the time required to learn the principles of good design makes sense. In the end, you are much more likely to end up with a database that meets your needs and can easily accommodate change. 

This article provides guidelines for planning a database. You will learn how to decide what information you need, how to divide that information into the appropriate tables and columns, and how those tables relate to each other. You should read this article before you create your first database.

Design process :

1. Determine the purpose of the database.
2. Find and organize the information required.
3. Divide the information into tables.
4. Turn information items into columns.
5. Specify primary keys.
6. Set up the table relationships.
7. Refine the design
8. Apply the normalization rules.