Book Image

The Data Warehouse Toolkit - Third Edition

By : Ralph Kimball, Margy Ross
5 (1)
Book Image

The Data Warehouse Toolkit - Third Edition

5 (1)
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

Low Latency Reality Check

The behavior of a customer in the last few hours or minutes can be extremely interesting. You may even want to make decisions while dealing with the customer in real time. But you need to be thoughtful in recognizing the costs and limitations of low latency data. Generally, data quality suffers as the data is delivered closer to real time.

Business users may automatically think that the faster the information arrives in the DW/BI system, the better. But decreasing the latency increases the data quality problems. Figure 20-6 summarizes the issues that arise as data is delivered faster. In the conventional batch world, perhaps downloading a batch file once each 24 hours, you typically get complete transaction sets. For example, if a commercial customer places an order, they may have to pass a credit check and verify the final commitment. The batch download includes orders only where all these steps have taken place. In addition, because the batch download is processed...