Carlos Sierra is the author of some popular tools for Oracle SQL Tuning: SQLTXPLAIN (SQLT), SQL Health Check (SQLHC) and Trace Analyzer (TRCANLZR), among others. Of late, he has also released two useful Oracle database tools by the names of eDB360 and eADAM. He is a coveted and regular speaker at several conferences related to Oracle performance, including Hotsos, OOW, UKOUG, RMOUG and IOUG. Carlos is currently a Practice Director at Enkitec. Prior to Enkitec he worked for Oracle for 17 years. Carlos is a frequent SQL Tuning practitioner constantly helping peers and other professionals to diagnose poorly performing SQL statements.
If you want to learn more about Carlos' contributions to the Oracle community visit his blog at http://carlos-sierra.net.