2 of 2 people found the following review helpful:
Excellent guide to implementation, 2006-11-02
While I have read a lot of books on this topic, this one goes above and beyond all. The emphasis on the practical aspects of how to implement a data warehouse was extremely useful, since all the steps are clearly laid out.
More than being a theoretical text, this book acts a practical guide to datawarehouse design and implementation.
The language is also easy to follow and the recommended readings/bibliography points to some excellent resources.
3 of 5 people found the following review helpful:
Excellent perspective and practical guidance, 2005-10-08
I have many books on the topic but this one has a special spot on my shelf. It toggles b/w high and low level concepts effortlessly to cover DW design and architecture in a way that provides guidance for a wide range of scenarios. The book addresses key cutting, DW audits and controls, hierarchy explosion tables, etl/data modeling/change mgt.. the list does go on. There are suggestions for sequencing out the activities involved in DW construction. This is a refreshing text that blends the large schools of DW thought and in the process comes up with all sorts of new insights that can be used in the trenches.
32 of 39 people found the following review helpful:
Not worth the money, 2005-03-02
I've been to seminars by Inmon, Kimball and Imhoff, as well as read many of their books. Kimball on the one hand, is generally clear and concise on the subject and obviously understands not only DW design and implementation concepts, but how they relate to various businesses and how the business really uses the data. He's also a fairly humble man in person.
Both Inmon and Imhoff on the other hand are rather self-aggrandizing (Inmon once waltzed into one of his keynote speeches dressed like a boxer to the theme from Rocky!), and both Inmon and Imhoff seem to have based their careers around bashing Kimball. In their desperation to present an alternative to Kimball's methodology and carve out their own niche, they've presented mostly incoherent, illogical and unusable ideas sometimes laced with anti-Kimball baggage. I get the feeling Inmon is kind of like James Martin was back in the 80's, churning out countless cookie-cutter style books of dubious quality.
I've designed a number of dimensional data warehouses and data marts that actually work years later using the Kimball approach, but honestly, every book I've read by Inmon and/or Imhoff has left me wondering who in the world actually uses their approach (if you can call it that) to build real-world data warehouses.
If you want to have a complete library and money is no object, by all means, read everyone's ideas on data warehousing and compare and contrast for yourself (I did - I must own fifty books on the subject - but I rely on only about 5-6 books in my day to day work as a DW architect - the rest are just taking up shelf space and reminding me how nice it is to be able to read reviews at places like Amazon before you buy). If money is an object and/or you are just starting out in the field and trying to learn the basics of DW design, do yourself a big favor and get the three excellent Kimball books (The Data Warehouse Toolkit, The Data Warehouse Lifecycle Toolkit and The Data Warehouse ETL Toolkit). The Adamson/Venerable book: Data Warehouse Design Solutions is a very useful adjunct for additional examples of real-world dimensional designs.
6 of 16 people found the following review helpful:
Excellent Reference for Data Warehouse Design, 2004-12-08
This book is a must read for anyone exploring or undertaking a data warehouse. It discusses the many issues regarding a data warehouse and balances the views authored by both Bill Inmon and Ralph Kimball. As the former publisher of DM Review magazine I have worked with many of the experts in data warehousing and have found that Claudia Imhoff is one of the best in the industry. Claudia is excellent at articulating and presenting the key issues and critical information that is essential to gain a firm understanding for data warehousing. She presents the theory behind the concepts which has been lost by many in the industry. At DM Review, I tried to get Ralph Kimball and Bill Inmon to debate the many issues behind data warehousing and data marts with little success. Bill Inmon was open to the debate but Ralph was not. Claudia is able to look at both viewpoints and separate what really matters between them. The major premise that still holds true today is that a data warehouse is essential to any organization that is trying to make tactical and strategic decisions. It should be built in an iterative fashion and should be the foundation for the creation of data marts. This book should be a key reference for anyone building a data warehouse.
53 of 64 people found the following review helpful:
Misinformation And Missing The Mark, 2004-05-18
If you want to build a Corporate Information Factory (CIF) I suppose this book is better than many of the previous attempts at teaching how to accomplish that goal. However, like many of the previous Inmon/Imhoff books, there is too much theory (unfocused at that) and not nearly enough practical/tactical content. If you are on the CIF bandwagon however, you will find the book very helpful as compared to most of the previous books on the topic.But that begs the question. Many a CIF or enterprise-wide project has been launched... yet most are cancelled long before reaching the finish line. This is reality. In the REAL world we have REAL deadlines and REAL budgets imposed by REAL business executives who have REAL problems to solve and it involves... oh by the way... REAL MONEY!
We have to deliver NOW! Well, ok, maybe not quite that fast, but you get the idea. The hard part is getting the data! Or is it? Using simple tools and a powerfully designed, highly detailed dimensional database, we have, for example, clients pulling their own data sets ready for import into statistical and mining packages. They think they have died and gone to heaven!
Foist a third normal form (3NF) design on them and their eyes roll... "Now, which of the available join paths is the right one for this business question?" and "Why is it taking so long for the query?" and "Will you pull the data for me?" Now we hear... "Instead of spending 80% or 90% of my time getting the data prepared, I spend 5% or 10% of my time doing that... so I have that much more time to actually think about the business." We have seen clients' ability to understand and drive their business expand beyond their own wildest imagination in very short order. It shows on their bottom line and they are very happy with that!
The whole point of BI - beyond all the data capture and cleaning and integrating and turning "data into knowledge", and making it easy for the user without dumbing it down, and all that stuff - the point of BI can be distilled down to one word: "Publish!" Booksellers don't hand you a photocopy of a handwritten manuscript. They do a lot of work with the "raw data" - typesetting and page numbers and table of contents and indexing and so on - and turn it into something accessible and useable... something we call a book. That's the point of BI. This book doesn't get it.
Too many CIF or "enterprise" projects have imploded under their own weight to slavishly duplicate the same mistakes. Too many dimensional systems have succeeded with huge return on investment to relegate the ideas to a dark corner.
If we stop the religious discussions (Mac vs. Windows, or the "Inmonites vs the Kimballites") and get to see how truly successful Business Intelligence (BI) systems work, we find the emphasis must be on using proper theory (not arguing it) and applying techniques that work NOW. More often than not, can you say "Dimensional!" Yes, CIF and all that has its place... but not nearly to the degree that this book would have you believe. The most successful clients have been the ones who bypassed all the "modeling wars" and used the data bus architecture of conformed dimensions. They didn't pick and chose a modeling idea or two; they actually studied Kimball and did it the right way. Dr. Codd, while addressing this question one day, asked me this question: "Would you run an OLTP system against a dimensional model?" My obvious answer was: "Of course not." "Why then," he asked, "do so many people try to do the opposite?"
The biggest "problem" with the dimensional approach is that people who do not truly understand it try to pick and chose techniques from it and graft those into their current ways... and fail... and bash it. Or, they don't understand it at all. Uh, sorry, it isn't the technique that is the problem.
The book purports to "answer" a message reply that Ralph Kimball posted on a discussion board some time ago. It does not. One can be certain that Ralph Kimball did not give permission to use his name on or in the book, as is done. Instead, the book does a very poor job of showing how to design and use dimensionally designed databases as a part of a larger architecture, illustrates a complete lack of understanding of the underlying principles, and then criticizes and limits the technique and its application. This does a terrible disservice to the reader... especially a reader who is trying to decide how to meet a real business need and is new to BI. I dislike speaking impolitely like this, but the truth is more important in this context. Also, on the back cover, they state that Ralph Kimball's "letter" was a challenge. It was not. It was merely a listing of many of the crucial issues in a useful BI environment addressed to an individual who had asked legitimate questions about BI. As for addressing these issues "head-on", the book does not do this at all.
Does this matter?
Of course it does. Real people buy this book and are led down a path that rarely leads to success. I realize that much of this review is not directly about specific details of the book. The details in the book are inconsistent, often unfocused, and sometimes downright misleading. The larger issue, and thus the focus of this review, is that the entire book is based on a premise that the CIF is "The Way" and that dependent dimensional data marts are grudgingly "ok". This is not the reality that many of us see in the business and education worlds.