Query Store is a new performance troubleshooting tool, fully integrated into the database engine. In my opinion, it is one of the best database engine features since 2005 and the introduction of OPTION(RECOMPILE). Query Store helps you to troubleshoot query performance by collecting information about queries, resource utilization, execution plans, and the other execution parameters. This information is stored in a database and therefore it survives server crashes, restarts, and failovers.

Query Store not only helps you to identify issues with query executions, but also lets you easily and quickly fix or work-around problems caused by poorly chosen execution plans. This fix can even be done automatically.

In this chapter, you will learn about the following points:

• Why Query Store has been introduced
• What Query Store is intended for and what it is not
• Query Store architecture
• How Query Store can help you to quickly identify and solve performance issues
• Automatic tuning in SQL Server 2017