Data warehousing is one of the hottest topics in the computing industry today. For business executives, it promises significant competitive advantage for their companies, while information systems managers see it as the way to overcome the traditional roadblocks to providing business information for managers and other end users. With the publication of this book comes the most comprehensive, practical guide to designing, building, and implementing a data warehouse on the market today.
Barry Devlin--one of the world's leading experts on data warehousing--is also one of the first practitioners in this area. In this book, he distills the insights and experiences gained over 10 years of designing and building data warehouses. Included are:
This book will become the key reference for any team undertaking the construction of a data warehouse. It is aimed primarily at the IS managers, architects, and designers involved in this process, as well as the end users having a key role in the evolving implementation of the data warehouse.
I. THE EVOLUTION OF DATA WAREHOUSING (THE HISTORICAL CONTEXT).2. The Data Warehouse—A Brief History.
II. PRINCIPLES OF DATA WAREHOUSING (ARCHITECTURE AND DESIGN TECHNIQUES).4. Types of Data and Their Uses.
III. CREATING THE DATA ASSET (BUSINESS DATA WAREHOUSE DESIGN).8. Business Data Warehouse Design.
IV. UNLOCKING THE DATA ASSET FOR END USERS. (THE USE OF BUSINESS INFORMATION).10. Designing Business Information Warehouses.
V. IMPLEMENTING THE WAREHOUSE (MANAGING THE PROJECT AND ENVIRONMENT).14. Obstacles to Implementation.
I first conceived of the idea of writing a book on data warehousing during a series of 2-day seminars known as the "Information Warehouse MasterClass" that I and a number of IBM colleagues had developed and presented around the world from 1992 to 1994. From the many companies that attended these seminars, one principal requirement was clear: they needed a common definition or architecture for a data warehouse, detailed enough to drive a consistent implementation within their organizations, yet concise enough to allow the whole company to understand and accept it. It was from the MasterClasses and the needs of these companies that I developed the representation and terminology of the data warehouse architecture used in this book.
In 1992, only a few real data warehouse implementations existed, each one hand-crafted and custom-built. Today, the vast majority of companies are planning to build or are actually building a data warehouse. While working with these companies over the years, I and other consultants saw the need to develop methodologies that cover the entire implementation process. This process continues to present major difficulties for many data warehouse implementations. I am convinced that companies today need a generalized and rational implementation approach to this complex process. The methodology described in this book is the result of crafting and proving the implementation approach over the years in real warehouse implementation projects.
Clearly, I have distilled the material covered here from interactions with many colleagues within IBM, with other consultants working in the field, and most especially from many hours of work with clients. Without their contributions, this book could not have been written. On the other hand, responsibility for any errors or misinterpretations is, of course, mine. It would be impossible to acknowledge by name everybody who has contributed to this book. To name anybody is to run the risk of omitting some valuable contributions; to those people I apologize in advance. However, I would like to especially thank a number of people either individually or collectively, whose support, knowledge, or time made this book possible:
Last, but not least, a special word of thanks to my family, Lil, Katherine, Alan and Emma, who have become convinced over the past year that I can exist only in symbiosis with my PC.1
1 The text of this book was produced entirely in Microsoft Word and the graphics were developed using Lotus Freelance Graphics.