Hotsos Symposium Speaker – Carlos Sierra

Carlos Sierra is a returning Hotsos Symposium presenter.


Carlos SierraCarlos Sierra is the author of some popular tools for SQL Tuning: SQLTXPLAIN (SQLT), SQL Health Check (SQLHC) and Trace Analyzer (TRCANLZR) among others.

Carlos spoke at Oracle OpenWorld in 2012. He has been a speaker at other Oracle performance conferences, including the recognized Hotsos Symposium and the Central Florida OUG (CFOUG).

Carlos currently works in the area of SQL Tuning for the Server Technologies (ST) Center of Expertise (CoE) at Oracle USA. His role includes the design and development of support tools for SQL Tuning, as well as the development and delivery of internal workshops for SQL Tuning. In addition to these two main functions, Carlos is constantly helping peers and other professionals to diagnose SQL Statements performing poorly.

Presentation Title

Understanding SQLTXPLAIN (SQLT) Main Report by Navigating through Some Samples


SQL Tuning is a daunting task. Too many things affect the Cost-based Optimizer (CBO) when deciding on an Execution Plan. CBO Statistics, parameters, bind variables, their peeked values, histograms and a few more are common contributors. The list of areas to analyze keeps growing.

Over the past few years, Oracle has been using SQLTXPLAIN (SQLT) as a systematic way to collect all the information pertinent to a poorly performing SQL statement and its environment. With a consistent view of this environment, an expert on SQL Tuning can perform a more diligent task, focusing more in the analysis and less in the information gathering. This tool could also be used by an experienced DBA making his life easier, at least when it comes to SQL Tuning.

This session uses some SQLT sample files to familiarize participants with navigation through the set of files and within the main SQLT report. Special attention is given to SQLT XTRACT and SQLT XECUTE files. All sections of the main SQLT report are explained.

Presentation Materials

Presentation materials are available online to attendees only.


The speaker schedule is as follows: