Book Review: SQL and Relational Theory

This book is intended to be an improvement over an earlier book on the same topic by the same author, namely 'Database in Depth: Relational Theory for Practitioners' . As the author states, the current book is a product of his realization of SQL being such a difficult language that it was far from obvious how to use it without violating relational principles even when covered in much depth in this earlier book, primarily for database practitioners.

One of the main features of the current book hence is the additional effort taken to have enough elucidation to connect the theory with practical SQL examples. While the theory discussion about the relational database model remains largely similar to the earlier book, there are exercises at the end of each chapter for better connecting the concepts with more examples. The answers to these exercises are included towards the end of the book.

There are about half a dozen chapters in the center of the book starting with “SQL and Relational Algebra I:The original operators” through to “Miscellaneous SQL Topics” which are the highlight of this book. There are some really lucid examples of implementing the relational definitions and theory in proper SQL in these chapters.

The slightly sarcastic tone of discussion of the author on the popular and theoretically doubtful usage of relational terms seems to be a constant companion for use of terms such as “duplicate elimination” instead of the more correct “duplication elimination”. This seems to be an attempt to challenging the maintenance of a continuous approach to try and match the SQL implementations to the theoretical definitions and concepts of Relational Model for Database Management.

One of the recent implementations of newer database models seem to be the Google proprietary Bigtable distributed storage systems. Since such proprietary models are out of public domain, it would be interesting comparing the principles behind them and the widely used relational database management systems.

To summarize, the book is a recommended read for all the database practitioners and other related professionals looking to match their implementations with the theoretical concepts and hence improving usability of the relational database model implemented within the enterprise.