Book Image

The Data Warehouse Toolkit - Third Edition

By : Ralph Kimball, Margy Ross
5 (2)
Book Image

The Data Warehouse Toolkit - Third Edition

5 (2)
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

The 34 Subsystems of ETL

With an understanding of the existing requirements, realities, and constraints, you’re ready to learn about the 34 critical subsystems that form the architecture for every ETL system. This chapter describes all 34 subsystems with equal emphasis. The next chapter then describes the practical steps of implementing those subsystems needed for each particular situation. Although we have adopted the industry vernacular, ETL, to describe these steps, the process really has four major components:

  • Extracting. Gathering raw data from the source systems and usually writing it to disk in the ETL environment before any significant restructuring of the data takes place. Subsystems 1 through 3 support the extracting process.
  • Cleaning and conforming. Sending source data through a series of processing steps in the ETL system to improve the quality of the data received from the source, and merging data from two or more sources to create and enforce conformed dimensions...