Book Image

The Data Warehouse Toolkit - Third Edition

By : Ralph Kimball, Margy Ross
Book Image

The Data Warehouse Toolkit - Third Edition

By: Ralph Kimball, Margy Ross

Overview of this book

The volume of data continues to grow as warehouses are populated with increasingly atomic data and updated with greater frequency. Dimensional modeling has become the most widely accepted approach for presenting information in data warehouse and business intelligence (DW/BI) systems. The goal of this book is to provide a one-stop shop for dimensional modeling techniques. The book is authored by Ralph Kimball and Margy Ross, known worldwide as educators, consultants, and influential thought leaders in data warehousing and business intelligence. The book begins with a primer on data warehousing, business intelligence, and dimensional modeling, and you’ll explore more than 75-dimensional modeling techniques and patterns. Then you’ll understand dimension tables in-depth to get a good grip on retailing and moved towards the topics of inventory. Moving ahead, you’ll learn how to use this book for procurement, order management, accounting, customer relationship management, and many more business sectors. By the end of this book, you’ll be able to gather all the essential knowledge, practices, and patterns for designing dimensional models.
Table of Contents (31 chapters)
Free Chapter
1
Cover
2
Title Page
3
Copyright
4
About the Authors
5
Credits
6
Acknowledgements
29
Index
30
Advertisement
31
End User License Agreement

Dimension and Fact Table Keys

Now that the schemas have been designed, we’ll focus on the dimension and fact tables’ primary keys, along with other row identifiers.

Dimension Table Surrogate Keys

The unique primary key of a dimension table should be a surrogate key rather than relying on the operational system identifier, known as the natural key. Surrogate keys go by many other aliases: meaningless keys, integer keys, non-natural keys, artificial keys, and synthetic keys. Surrogate keys are simply integers that are assigned sequentially as needed to populate a dimension. The first product row is assigned a product surrogate key with the value of 1; the next product row is assigned product key 2; and so forth. The actual surrogate key value has no business significance. The surrogate keys merely serve to join the dimension tables to the fact table. Throughout this book, column names with a Key suffix, identified as a primary key (PK) or foreign key (FK), imply a surrogate...