Features that rely on the Query Store
When the QS was first introduced in SQL Server 2016, it was turned off by default to avoid potential impact on production workloads, as Microsoft just didn’t know how it would behave with the millions of workload permutations executing out in the wild. Over time, there have been numerous scalability improvements, and better default settings were introduced in Azure and SQL Server 2019, both from customer input and Microsoft Engineering’s own experience with the QS. This resulted in the ability to have QS turned on by default for new databases, starting with SQL Server 2022.
Having the QS enabled by default is great for database professionals, but perhaps more importantly, it becomes part of an entire feedback system that gives the SQL Database Engine rich information about query performance. Some of that information can be used to ensure the Query Optimizer can shortcut certain decisions, learn from past performance degradation...
