Reviewing Optimized Locking Results

Louis Tochon wants to know if optimized locking actually ran:

In the first case, SQL Server escalated the row locks to an X lock on the whole table. In the second, there is no escalation anymore, only one X lock on the transaction ID (XACT), next to the intent lock (IX) on the table (the IS lock in both results is on the small function I used to run this query).

That is nice in a demo, but on a real server nobody is looking at sys.dm_tran_locks at the right moment. I wanted to know how a DBA can check what optimized locking does once it is enabled. SQL Server 2025 has a few Extended Events for that, and I found some of their fields easy to misread and one of them reports LAQ as enabled on a database where it never ran once.

Click through to learn more.