In the last 2 years since I last taught my Mastering classes, the SQL Server performance tuning game has changed a lot!
SQL Server 2019 has achieved widespread adoption, meaning more of your servers have access to more tuning tools SQL Server 2019 has gotten really stable, meaning it’s safer to use tools like Query Store and last-actual-execution-plan that I used to be skittish about Cumulative updates are changing server behaviors, and I’m seeing new problems at clients, plus in the wider population of SQL ConstantCare®, like the TokenAndPermUserStore and lock memory consumption Azure SQL DB and Managed Instances