If an update statement's query plan does go parallel, does it guarantee a communication buffer resource deadlock, or is that determined by whether the parallel plan is using all cores?

1 Answer 1


From the documentation:

The update and delete operators in a parallel query execution plan are executed serially, but the WHERE clause of an UPDATE or a DELETE statement may be executed in parallel. The actual data changes are then serially applied to the database.

As to your second question,

does it guarantee a communication buffer resource deadlock

Any deadlock is predicated on the query / queries being run and how they are structured and executed, SQL Server does not inherently guarantee any deadlocks on its own.

  • Interesting. Thank you for the link to the documentation, I was not able to find that earlier. However, I wonder why this type of deadlock does not occur more frequently, particularly in Data Warehouses that process updates to dimension records? Sep 15, 2020 at 18:17

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.