Jesper Wisborg Krogh has worked with MySQL databases since 2006 both as an SQL developer, a database administrator, and for more than eight years as part of the Oracle MySQL Support team. He has spoken at MySQL Connect and Oracle OpenWorld on several occasions, and addition to his books, he regularly blogs on MySQL topics and has authored around 800 documents in the Oracle Knowledge Base. He has contributed to the sys schema and four Oracle Certified Professional (OCP) exams for MySQL 5.6 to 8.0. He earned a PhD in computational chemistry before changing to work with MySQL and other software development in 2006. Jesper lives in Sydney, Australia, and enjoys spending time outdoors walking, traveling, and reading. His areas of expertise include MySQL Cluster, MySQL Enterprise Backup, performance tuning, and the Performance and sys schemas.