The book is simply spectacular, both for the quality of its writing as well as the depth of the material. Practical? Indeed, indispensible!
The three authors, Richmond Shee, Kirti Deshpande, and K Gopalakrishnan, have done a wonderful job in organizing a enormous subject area into manageable chunks. They have also managed to render potentially bone-dry source material into very readable text, interspersed heavily with code examples and output, sidebars, and analogies. This is a good read as well as an authoritative reference. I'm still unable to read it steadily for long periods of time, as the analogy of trying to drink from a fire-hose is relevant here. But picking it up and reading different sections, treating it like a reference, has proved rewarding. Richmond, Kirti, and K had an absolute "dream team" of reviewers on this book in Kyle Hailey, John Kanagaraj, Craig Shallahamer, and Graham Wood. The combined efforts of the three authors and the four technical editors blows my mind.
All I can say is - get it! You may (like me) not read it immediately. But, keep it handy. Along with the Google, Ixora, Asktom, JLComp, MetaLink websites, this book is the place to find explanation for the unexplainable in Oracle. Start skimming through it and recognize situations that had previously baffled now being explained (and proved) in full. It is like a light coming on.