C. J. Date is an independent author, lecturer, researcher, and consultant specializing in relational database theory. My introduction to his work came while I studied the Php/SQL course series online via the O'Reilly School of Technology. I received a copy of Database in Depth: Relational Theory for Practitioners, ISBN 0-596-10012-4, to accompany the online coursework. A couple of chapters into Database Design and Relational Theory I stopped and read again the aforementioned Database In Depth as a refresher.
Database Design and Relational Theory: Normal Forms and All That Jazz is about the logical design of a database as it relates to the relational data model. It's about the theory of the relational model and the accompanying algebra. These concepts are separated from physical design as physical design relates to how a particular logical design will map to actual physical storage.
The book is written for an audience accustomed to the terminology and concepts of the relational model. Definitions are introduced moving from the informal to the formal. Throughout the book the discussion involves relations, relvars, tuples, functional dependencies, join dependencies and various algebraic operators. If all this seems foreign, then I would suggest another text to be read as prerequisite to this book. Admittedly, I do not have a background in computer science or mathematics. I found the material difficult at times but not overly so. I think that after reading this book I have a much better grasp on normalization when it comes to creating my own database.
I would recommend this book to those readers with a desire to learn about relational design theory. It is product agnostic with mentions of SQL limited to instances where SQL breaks from the relational model. It is an advanced text and requires thought and concentration commensurate to the fields of computer science and mathematics.
Disclosure: I recieved a free ebook copy for review purposes.