Oracle cost based optimizer cost-based

Excellent webinar by Randolf Geist :
“When it comes to writing efficient queries there are a few key concepts that need to be understood. One of them is the Oracle Cost-Based Optimizer (CBO). Although it’s called a cost-based optimizer it’s actually not the cost we need to focus on primarily to understand why the optimizer makes certain decisions.

In this webinar, you will learn the basics of the CBO, see why it is crucial that the optimizer’s picture of the data fits reality, why cardinality and selectivity estimates matter so much, and which key concepts the optimizer’s model surprisingly doesn’t cover (yet).

Live demos throughout the presentation will enable you to see the CBO in action, and you will learn about leading the optimizer in the right direction when your knowledge of the data is better than the optimizer’s.”

A live Q+A session with Randolf Geist follows the presentation.