As one of the product managers on the Oracle Database team, I’m super excited to be returning to Italy to participate in the Italian Oracle User Group Tech Days 2020.

I first had an opportunity to visit Italy on my honeymoon, 14 years ago and it was love at first sight for me! I have returned many times since then, as I can’t get enough of the culture, food and of course of the marvelous people.

Maria Colgan - ITOUG Tech Days 2018
Maria Colgan at ITOUG Tech Days 2018

On this visit, I’m excited to have an opportunity to present two sessions as part of the Tech Days. My first session, entitled “Explain the Explain Plan”, is probably the most popular presentation I have ever created.

After all, what developer or DBA do you know that hasn’t been asked at some point in their career, “why is the query or report running slowly?”.

Knowing how to interpret the execution plan for a SQL statement and understanding why the Optimizer made the decisions it did, can go a long way to answering this question. It can also help you understand why you need to supply certain pieces of information to the Optimizer in order to help it produce the plan you want.


In this session, I explain how to generate, and view execution plans, as well as, describing the different aspects of an execution plan, from selectivity to parallel execution. I will also discuss what information you should be gleaming from the plan and how it affects the execution. Finally, I will share a set of corrective measures that can be used to improve each aspect of the plan. I know that sounds like a lot to pack into 45 minutes, but I promise it will be a fun filled and educational ride!

My second session builds on the first and is called “Harnessing the Power of Optimizer Hints”. Although I am not a strong supporter of adding hints to SQL statements for a lot of reasons, I do know that from time to time it can become necessary to influence the plan the Optimizer chooses, which is why I put this session together.

Optimizer Superhero

In this session I explain why Oracle introduced hints, when and how they should be used and why some hints seem to be ignored by the Optimizer. I will also provide you with a set of techniques to help you apply the right hint, in the right place, at the right time to get the most efficient execution plan. But be warned this session won’t make you an Optimizer superhero (HintMan or HintWoman) in just 45 minutes!