Assume that you have a script that uses event notifications for AUDIT_LOGIN and AUDIT_LOGIN_FAILED events in Microsoft SQL Server 2016 and 2017. When you run the script, you will notice that the TempDB grows rapidly in size.
You can use the below query to check if space allocated to TempDB internal objects is correctly deallocated.
SELECT * FROM ( SELECT TS.internal_objects_alloc_page_count , TS.internal_objects_dealloc_page_count, [Net Allocation MB] = CAST((TS.internal_objects_alloc_page_count - TS.internal_objects_dealloc_page_count) AS DECIMAL(15, 2)) / 128 , TS.session_id , ER.command FROM sys.dm_db_task_space_usage TS INNER JOIN sys.dm_exec_requests ER ON ER.request_id = TS.request_id AND ER.session_id = TS.session_id where TS.session_id < 50 ) internal where [Net Allocation MB] != 0
This issue occurs because of a regression in Cumulative Update 6 for SQL Server 2016 Service Pack 1.
This issue is fixed in the following cumulative updates for SQL Server:
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Learn about the terminologythat Microsoft uses to describe software updates.