Most useful book I've read, taking into account its size. Bought it only for Sql Server explanations, but learned something about Oracle too. Willing to take profiler and improve, improve, improve... Seriously speaking - coherent explanation of tough stuff and putting into system a lot of fragmentary pieces of knowledge.
This book is easy to read, but still really informative. It helps simplify the whole process a database system goes through to execute SQL queries. It helps understand how to write faster queries. A really impressive job done by Markus Winand.
This book is an excellent study material on the best techniques to enhance the performance of the SQL query. It takes into account different databases: Oracle, SQL Server, MySQL and Postgresql (with a special preferences for the first one). It is written in a flowing, very understandable language, and paginated impeccably. Little bad only the missing number of pages' chapter in the header of your pages. But the content is really top-notch, complete with graphs of execution plans to better understand how to operate the query. Is an indispensable manual for anyone, DBA, developer or system administrator, cares about the performance optimization of the query.