Simple play icon Course
Skills Expanded

SQL Server: Troubleshooting Query Plan Quality Issues

by Joe Sack

Learn how to identify, diagnose, and prevent problems where SQL Server chooses the incorrect query plan for your critical queries, applicable to developers, DBAs, and anyone responsible for SQL Server, from SQL Server 2005 onwards

What you'll learn

There are many problems that can lower the performance of your workload and one of the most common is an incorrect query plan. Often the poor query plan is chosen because the cardinality estimate is wrong - the estimate by the query processor of how many table rows will be involved in the query. This course shows you how to recognize when the query processor has an incorrect estimate, along with explaining and showing a multitude of possible causes, plus how to fix them. The course starts with explaining why query plan quality is important, and then shows how to easily spot cardinality estimate issues from examining query plans. The majority of the course shows all the possible causes of cardinality estimates being incorrect along with how to fix them, and more than 25 demos to walk you through practical examples of the concepts and problems in the lectures. This course is perfect for developers, DBAs, and anyone responsible for performance tuning on SQL Server. The information in the course applies to all version from SQL Server 2005 onwards.

Table of contents

About the author

Joe Sack is a Principal Program Manager in the SQL Server and Azure SQL Database product team at Microsoft, with a focus on query processing. With over 19 years of experience in the industry, Joe is an author and speaker, specializing in performance tuning and optimization.

Ready to upskill? Get started