Basics of the Cost Based Optimizer

Comparto una serie de articulos sobre el optimizador de Oracle (CBO) de Jonathan Lewis publicada entre junio y noviembre de este año en http://allthingsoracle.com

This series on Oracle’s Cost Based Optimizer is aimed at the less experienced DBAs and developers to help them understand what the optimizer is trying to achieve, how it arrives at an execution plan, why it makes mistakes, and (perhaps most importantly) how to recognize the source of those mistakes and so address the resulting problems in an appropriate fashion.

I will try to avoid going into extreme technical detail though I will outline a few of the slightly more technical issues and mention a few URLs that go into greater depth on particular topics.

To get the best out of this series you will need to have some experience with reading execution plans, especially when we look at the “trouble-shooting” side of optimization.

Basics of the Cost Based Optimizer – Part 1

Basics of the Cost Based Optimizer – Part 2

Basics of the Cost Based Optimizer – Part 3

Basics of the Cost Based Optimizer – Part 4

Basics of the Cost Based Optimizer – Part 5

Basics of the Cost Based Optimizer – part 6