Execution plans explained
This page contains the description for my conference session “Execution plans explained”, and links to the slide deck and demo code used in this presentation.
Description
| Target audience | Developers, database developer, and DBAs, who want to learn how to use execution plans to understand why queries are slow, and how to improve their performance. |
| Short description | The workshop starts with the basics of execution plan: what they are, where to find them, and of course how to read them. After that, we’ll cover all of the operators you will commonly encounter in execution plans. We’ll explain what they do, but also how they do it. Armed with this knowledge, you can tackle any execution plan to figure out which part makes a query slow, and how to fix that! |
| Duration | This session is a full-day workshop |
| Full abstract | You probably have some tricks up your sleeve for dealing with slow queries. Index the columns in the join and where. Rewrite the WHERE clause to enable index usage. Tinker with the join order, or perhaps even break up the query in smaller parts. Those tricks work. Sometimes. Not always. And when they don’t, your job suddenly gets frustrating!
Sometimes, you wish you knew WHY a query is slow. So that you can target your changes exactly right, at precisely the root cause of the slowness. And the good news is, there already exists a way to find the root cause of bad performance. You “only” need to learn to work with execution plans. In this full-day workshop, you will learn everything you need. You will learn what execution plans are, and where you can find them. You will learn the basics of how to read execution plans. And you will learn all you need about all of the commonly encountered operators in execution plans: what their function is, how they operate, and what effect that has on performance. In short: After attending this workshop, you will know how to obtain an execution plan for a slow running query, and you will know how to look at that plan and find the spot where it hurts, so that you know what to do to fix the performance issue. Regardless of whether you have never seen an execution plan before, or whether you already have experience working with execution plans, this workshop will teach you how to look at an execution plan and then KNOW why your query is slow … and what you can do to fix that! |
Resources
Click here to download a ZIP file containing the slide deck and demo code used in this presentation. Note that the ZIP file is encrypted with a password that will be given to you during the precon. Please respect the huge time investment to create the content for a full-day workshop by not sharing the password or the content of this archive with others.
Note that Windows’ built-in unzip functionality doesn’t support passwords in some versions. Please use a too such as WinRAR, WinZIP, or 7-Zip to open this file. For a Mac, try iZip.
(Note: my presentations tend to evolve over time, so the version you find here may not be an exact match for the version you witnessed).