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This wait type is when a thread switches to preemptive mode as part of committing changes to the list of Extended Event sessions on the instance.
(Books Online description: N/A)
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Added in SQL Server version:
Removed in SQL Server version:
Extended Events wait_type value:
The map_key value in sys.dm_xe_map_values is 542 in 2008 and 2008 R2, 590 in 2012, and 606 in 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.
I have not seen this wait type be a noticeable contention point.
Known occurrences in SQL Server (list number matches call stack list):
- Committing the event session changes (in this case, as part of a CREATE EVENT SESSION operation)
- Committing the event session changes (in this case, as part of starting up the master database)
And other similar call stacks.
Abbreviated call stacks (list number matches known occurrences list):
XdesRMFull::`vector deleting destructor’+14