Composite Primary Key or Extra ID Column: Which is Best for Database Design?

Composite Primary Key vs. Additional "ID" Column: A Closer Examination

Introduction

Database design often involves choosing between using a composite primary key, combining multiple attributes, or an additional "ID" column as the primary key. In this article, we will explore the factors that influence this decision, using a practical example to illustrate the pros and cons of each approach.

Candidate Key vs. Primary Key

Before diving into the main question, it's important to clarify the concepts of a candidate key and a primary key. A candidate key is a set of attributes that uniquely identifies each row in a table. A primary key is a candidate key that is selected by the database designer to uniquely identify the rows in the table.

Case Study: The "Books" Table

Consider the "Books" table with the following attributes:

• Author

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