The Oracle SQL Certified Expert exam covers several topics that are not covered in books that are geared towards the SQL Fundamentals exam. It is for that reason that I purchased this book to use as a study guide for the Oracle SQL Certified Expert exam. I recently passed the exam and give full credit to the time I spent going through this book and taking the practice tests.
The books assumes a little knowledge of SQL but I think it is a great guide for both beginners, and experts alike. It is well organized and has a great index. You can read it from beginning to end and it makes logical sense, or you can simply use it as a reference to look up the portions you are interested in. Because the book is geared towards passing the exam and not simply to provide more general SQL knowledge, you won't find any examples that you work on, alongside the book, as you read. Some people might find it hard to learn that way, but for me it was great. I didn't need to have a computer in front of me to try out the code to understand what it meant. This also allowed the book to focus on some of the more subtle and conceptual aspects of the SQL language and how Oracle has implemented it. I think that is key to having passed the exam. Because the book teaches the concepts behind the SQL language, instead of just giving syntax examples, it helps you correctly answer questions that might not directly relate to examples given in the book. For example, the book has a great section on the meaning of "NULL" which is used in a lot of "trick" questions. It might not give you all possible examples of where "NULL" can be used in a question, but it does give you a good understanding of what "NULL" means in the SQL context and therefore how to answer questions that could be affected by "NULL" in their code.
My biggest gripe with the book is the fact that it only came with 70 test questions on the CD, and that the CD is Windows only. 70 questions is the equivalent to 1 practice exam. You can download an additional 70 questions from the web after registering with the publisher, but even doing that only gives you 2 practice exams worth of material. It doesn't take long to memorize all the correct answers for 140 questions. I would have preferred the book if it came with at least twice as many questions. I also think its kind of ridiculous that the CD itself is not cross platform. Such practice exams could have been developed in a way which would have allowed me to run it under Mac OS X or Linux. Instead I had to run Windows under virtualization just to take the practice exam.