This is a very technical and theoretical book about oracle cost based query optimisation fundamentals. POINT .
I have worked a day with Jonathan and he knows a lot about oracle optimisation, the hardware it runs on and about the operating systems Oracle runs on. But… in my opinion this book really goes back to theoretical costs for queries, with a lot of dry calculations, and do not bring you to the problem with your query and how to tackle it. It is not a practical book. I think the book Oracle Wait Interface — which is a more practical guide to oracle database performance diagnostics & tuning — is indeed much more practical and open minded book which takes a complete new insight to optimising queries.