Execution plans ... where do I start?
Proposed session for SQLBits 2026TL; DR
Execution plans can tell you exactly why a query is slow. But how?
In this session you will learn how to obtain execution plans, and how to start reading and understanding them.
Session Details
SQL (the language) is not a third generation language, where the developer tells the computer every step it needs to take. It is a declarative language that specifies the required results. SQL Server itself will figure out what steps it takes to get to those results. Most of the time, that works very well.
But sometimes it doesn't. Sometimes a query takes too much time. You need to find out why, so you can fix it. That's where the execution plan comes in. In the execution plan, SQL Server exposes exactly which steps it took for your query, so you can see why it's slow.
However, execution plans can be daunting to the uninitiated. Especially for complex queries. Where do you even start?
In this session you will learn how to obtain execution plans. and how to start reading and understanding them.
But sometimes it doesn't. Sometimes a query takes too much time. You need to find out why, so you can fix it. That's where the execution plan comes in. In the execution plan, SQL Server exposes exactly which steps it took for your query, so you can see why it's slow.
However, execution plans can be daunting to the uninitiated. Especially for complex queries. Where do you even start?
In this session you will learn how to obtain execution plans. and how to start reading and understanding them.
3 things you'll get out of this session
Learn the importance of execution plans.
Learn where to find execution plans.
Learn how to read execution plans.
Speakers
Hugo Kornelis's other proposed sessions for 2026
Approximate functions: How do they work? - 2026
Execution plans explained - 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