SQL Performance Explained Review: The Best Book on Indexes?
An honest review of SQL Performance Explained by Markus Winand: what it teaches about indexes, who it is for, and whether to buy the book or read it free online.
Performance Tuning Books
Books on query tuning, indexing and execution plans.
5 Best SQL Performance Tuning Books (Including 2 Free Ones)
The best books for SQL performance tuning: indexes, execution plans and troubleshooting slow SQL Server queries. Two of them are free ebooks.