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Maria Colgan

Optimizer Hints: Top Tips for Understanding and Using Them


Maria Colgan, Oracle


 

Abstract

The goal of the Oracle Optimizer is to examine all possible execution plans for a SQL statement and to pick the one with the lowest cost, which should be the most efficient. From time to time, it may become necessary to influence the plan the Optimizer chooses. The most powerful way to alter the plan chosen is via Optimizer hints. But knowing when and how to use Optimizer hints correctly is somewhat of a dark art. This session explains in detail how Optimizer hints are interpreted, when they should be used, and why they sometimes appear to be ignored. By attending this session people should walk away with the necessary knowledge to apply the right hints, in the right place, at the right time to get the most efficient execution plan. 

Speaker Biography

Maria Colgan is a master product manager at Oracle Corporation and has been with the company since version 7.3 was released in 1996. Maria‚Äôs core responsibility is creating material and lectures on the Oracle Database and the best practices for incorporating it into your environments. She is also responsible for getting the feedback from our customers and partners incorporated into future releases of the product. Prior to this role; she was the product manager for Oracle Database In-Memory and the Oracle Database query optimizer.  Maria is the primary author of the SQLMaria blog https://sqlmaria.com and a contributing author to the Oracle Optimizer blog http://blogs.oracle.com/optimizer.