XE_LIVE_TARGET_TVF

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Description:

This wait type is when a thread is performing operations while a query is pulling data from an XEvent session live data viewer (possibly in SSMS). Note that this is a preemptive wait, so the thread continues executing on the processor until the operation is complete.

(Books Online description: N/A)

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Added in SQL Server version:

2012

Removed in SQL Server version:

N/A

Extended Events wait_type value:

The map_key value in sys.dm_xe_map_values is 734 in 2012 and 752 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.

Other information:

I have not seen this wait type be a noticeable contention point.

Known occurrences in SQL Server (list number matches call stack list):

  1. Waiting for a session events to collect data while watching in a live data viewer

Abbreviated call stacks (list number matches known occurrences list):

  1. SOS_Task::PostWait+9e
    SOS_Semaphore::Wait+1a2
    XE_LiveTargetTVF::InternalGetRow+ef
    CQScanTVFStreamNew::GetRow+d5
    CQueryScan::GetRow+81
    CXStmtQuery::ErsqExecuteQuery+54a
    CXStmtSelect::XretExecute+2e7
    CMsqlExecContext::ExecuteStmts<1,1>+427
    CMsqlExecContext::FExecute+a43
    CSQLSource::Execute+86c
    ExecuteSql+863
    CSpecProc::ExecuteSpecial+2a2
    CSpecProc::Execute+2c5
    process_request+a57
    process_commands+4a3
    SOS_Task::Param::Execute+21e
    SOS_Scheduler::RunTask+ab