Grant Fritchey looks for an answer:
Let’s face it, most of the time, you probably don’t want your SQL Server execution plans to go parallel. After all, that’s why, instead of adjusting the Cost Threshold for Parallelism (as you should have), you’ve set the Max Degree of Parallelism to 1 (I see you out there). However, some of you recognize that, in fact, some queries need to run in Parallel.
Yet, sometimes, a query you think should run in parallel doesn’t. Can you tell why a plan didn’t go parallel?
Read on to learn how.