Thanks to the following people who helped in various ways: Brian Aker, Johan Andersson, Espen Braekken, Mark Callaghan, James Day, Maciej Dobrzanski, Ewen Fortune, Dave Hildebrandt, Fernando Ipar, Haidong Ji, Giuseppe Maxia, Aurimas Mikalauskas, Istvan Podor, Yves Trudeau, Matt Yonkovit, and Alex Yurchenko. Thanks to everyone at Percona for helping in dozens of ways over the years. Thanks to the many great bloggers^[3] and speakers who gave us a great deal of food for thought, especially Yoshinori Matsunobu. Thanks also to the authors of the previous editions: Jeremy D. Zawodny, Derek J. Balling, and Arjen Lentz. Thanks to Andy Oram, Rachel Head, and the whole O’Reilly staff who do such a classy job of publishing books and running conferences. And much gratitude to the brilliant and dedicated MySQL team inside Oracle, as well as all of the ex-MySQLers, wherever you are, and especially to SkySQL and Monty Program.