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Added in SQL Server version:
Removed in SQL Server version:
Extended Events latch_class value:
Maps to the AM_IOAFF_WAITING_WORKER_QUEUE map_value in sys.dm_xe_map_values.
The map_key value in sys.dm_xe_map_values is 20 in 2008 and 2008 R2, and 15 in 2012 and 2014 RTM. After 2014 RTM, you must check the DMV to get the latest value as some map_key values have changed in later builds.
Known occurrences in SQL Server (list number matches call stack list):
Abbreviated call stacks (list number matches known occurrences list):