Customer Reviews

Common Warehouse Metamodel: An Introduction to the Standard for Data Warehouse Integration

5 star:		(4)
4 star:		(1)
3 star:		(0)
2 star:		(1)
1 star:		(1)

 

 

Ok, I am a known heretic. I am not impressed by the CWM model. It is oriented toward the object-oriented implementation of a tool for metadata exchange, not toward representing the things business people would be looking for in a meta data repository.

This book is better than the on-line specification at describing the model--which was really incomprehensible--but this is at the expense of completeness. Definitions are not available for all classes and the ones that are are not clear (to me at least). The relationships are barely defined at all.

In fairness, the model is so complex that it may not be possible to describe clearly to anyone not deeply immersed in the language of object-orientation. The team of authors is further hampered by its use of UML. The notation does not permit a complete inheritance tree to be portrayed in a diagram if the diagram is of less than the entire model. Two classes may be related, but you can't see this because the relationship is between great grandparents, shown on a different page.

I'll say at the start that this is not my kind of book. I prefer books which are useful, enlightening or both. This didn't seem to be either. From page 3: "The mission of this book is to provide a single, coherent, and comprehensive overview of the OMG's Common Warehouse Metamodel, which is easy to read.". It may be slightly easier to read than the raw specification, but it's a lot less useful. The most telling point is further down the same page where it admits to really being just an introduction to a forthcoming "Warehouse Metamodel Developers Guide".

For an overview, the book is really short on examples. It's got lots of vague UML diagrams and pretty pictures like you might see on a powerpoint slide, but not a single worked example to show how all the buzzwords and technologies might actually fit together. I also have great problems with their use of UML as a language to actually specify data models, processes and so on. For me UML is a tool to help express intentions to people, not supply details to processing software, but this book seems to ignore the difference.

If you know nothing about meta-modelling, and want the sort of information you can get from the slides of a conference presentation, this may be a useful book. If you want to understand the details, or (gosh) actually get a job done, then this book will just frustrate you.

By far, the finest presentation of a new (to me) concept I have seen in a long time. Structure of book is ideal, with a strong writing style, fantastic use of graphics, and examples that aid in understanding. I knew virtually nothing about CWM before reading this book -- I know a good deal now. Excellent, understandable writing style combined with superb technical information...a definite "stew" for the CWM-hungry mind. Bon appetit!

The overall organization of the book: its introduction of topics, clear and concise definitions and illustrative examples made for easy reading, even for concepts with which I was unfamiliar. The structure, content and motivation for the CWM classes and packages were clearly presented as was their use, interaction, extensibility and applicability through thoughtfully constructed examples.

A must read for managers, system architects and software developers grappling with data warehouse integration projects.

I can't believe the previous reviewer. He basically said he didn't like CWM or UML, therefore the book is obviously bad ?!?

The project I am just starting is a large data mining effort that will be integrating multiple data warehouse and data mining tools. I knew we needed CWM from some earlier work with metadata repositories, but did not have the energy to dig into the OMG specification. This book gave me exactly the overview I was looking for; as an earlier author said, "This book covers all the practical steps for planning, implementing, and deploying CWM technologies". I would like to give it at least 7 stars to average out the previous irrelevant review...

A real boon to data warehouse developers. This book covers all the practical steps for planning, implementing, and deploying CWM technologies. It provides a clear roadmap to integrating data warehouses. An essential resource.

A very clear introduction to the Common Warehouse Metamodel for data warehousing. It doesn't just explain what it is, but shows how it works. When you're done reading this book, you're ready to start developing.