Carlos Sierra is a regular speaker at Oracle users groups on topics related to performance and SQL Tuning. He is the author of some legacy tools such as SQLTXPLAIN and SQLHC and some modern ones such as eDB360 and eSP. Carlos has over 20 years of experience in Oracle Databases, and many more on legacy UNISYS and IBM mainframes. Carlos currently works as a consultant for Accenture Enkitec Group, where he leads the Oracle Database health-check team. His home is Seattle now, after 20 years in sunny Florida. Together with his wife Kelly, they have raised four responsible young adults and now they enjoy the peace of an empty nest. Carlos likes helping and mentoring others, and contributes to the Oracle community as much as his free time permits.