This book is both a reference and tutorial. The first couple of chapters are more reference in nature describing the concepts of dimensional modeling. The remainder of the book functions as a tutorial showing how to implement the concepts using a variety of tools in Ruby. The tutorial makes use of RDBMS systems like MySQL and PostgreSQL and includes ETL examples. Non-RDBMS system like Berkeley DB are also discussed and used to quickly process extreme amounts of data. The book then shows how to process and visualize data using various graphing and reporting techniques in Ruby, Javascript, Flash and CSS.  A Git repository is used to explain and implement the concepts found throughout the book.