Michael Raithel has written an excellent learning and reference manual about SAS indexes. This book is well thought out, and the information is presented aptly so it can be used by a SAS beginner as well as the most advanced SAS developer to learn more about SAS indexes. Michael covers indexes so that you will understand when, why, and where to use indexes. He includes plenty of easy-to-follow code examples to help you fully comprehend the strengths and weaknesses of indexes. He also explains when and where NOT to use indexes. You need this manual in your SAS library when building SAS applications involving the need for performance and speed to deliver your data to your end users or clients. "I strongly encourage ALL SAS users (beginners to advanced levels) to purchase this manual as an effective learning and reference tool. Your money will be well spent on this book. I am pleased to add this to my 'must have' SAS manuals. Now that I have read Michael's new book, I will be looking for more books by this author knowing how well he presents his materials to an audience of varied experiences and skill levels.