Execution plans explained
Proposed session for SQLBits 2026TL; DR
Whether you've never seen an execution plan before, or whether you already have experience 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!
Session Details
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!
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!
3 things you'll get out of this session
Learn where to find and how to read execution plans.
Learn what each operator does and how that affects performance.
Start to understand interactions between operators.
Speakers
Hugo Kornelis's other proposed sessions for 2026
Approximate functions: How do they work? - 2026
Execution plans ... where do I start? - 2026
Execution Plans in Depth - 2026
Five stages of grief - internals of a hash spill - 2026
Here’s the execution plan … now what? - 2026
Normalization beyond Third Normal Form - 2026
Normalization beyond Third Normal Form, part 2 - 2026
Performance and execution plan improvements in SQL Server 2025 - 2026
Performance and execution plan improvements in SQL Server 2025 (part 2) - 2026