Erik Darling lays down a lesson for us:
When you’re looking for queries to tune, it’s important to understand which part is causing the slowdown.
That’s why Actual Execution plans are so valuable in newer versions of SQL Server and SSMS. Getting to see operator timing and wait stats for a query can tell you a lot about what kind of problem you’re facing.
Let’s take a look at some examples.
Let’s, shall we?