Falling BETWEEN the Cracks Of Cost-Based Optimizer

Falling BETWEEN the Cracks Of Cost-Based Optimizer

This session focuses on a cardinality mis-estimate dealing with ‘BETWEEN’ conditions and ‘OR’ expansions in a query which caused a real-world performance problem.

We’ll use some mathematics to understand exactly what went wrong.

About Patrick

Patrick started as a C Developer, before gradually migrating towards Database Administration, focused mainly on Oracle performance.

He spent some time living and working in Hong Kong, and now resides in Portugal where he still does a little remote work, and spends the rest of the time walking his dog, watching movies, trying to learn the language and generally recovering from his time in Hong Kong.

Patrick has presented at various international Oracle usergroup and open-source conferences.