Execution plans … where do I start?
This page contains the description for my conference session “Execution plans … where do I start?”.
|Target audience||Database developers and DBAs who understand that execution plans can be a good tool to improve query performance, but have no experience yet with this tool.
No prior knowledge of execution plans is required, but attendees are expected to understand indexes, and to be able to read and write basic and slightly advanced T-SQL queries.
|Short description||A very thorough explanation of how various execution plan operators work, and how they interact with each other.|
|Duration||The ideal length for this session is 60 – 75 minutes.|
|Full abstract||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.
Click here to download a ZIP file containing the slide deck and demo code used in this presentation.
(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).