This book is a deep dive into perhaps the single-most important facet of good performance: indexes, and how to best use them. The book begins in the shallow waters with explanations of the types of indexes and how they are stored in databases. Moving deeper into the topic, and further into the book, you will look at the statistics that are accumulated both by indexes and on indexes. You'll better understand what indexes are doing in the database and what can be done to mitigate and improve their effect on performance. The final destination is a guided tour through a number of real life scenarios showing approaches you can take to investigate, mitigate, and improve the performance of your database.