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Description:
This wait type is when a thread has issued an asynchronous read from a bulk load source file and is waiting for the I/O to complete.
(Books Online description: “Occurs when SQL Server waits for a bulk load I/O to finish.”)
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Added in SQL Server version:
Pre-2005/2005
Removed in SQL Server version:
N/A
Extended Events wait_type value:
The map_key value in sys.dm_xe_map_values is 149 in 2008 and 2008 R2, and 153 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.
Other information:
As general guidance for I/O wait types, if the wait time is higher than acceptable I/O latencies for your environment, investigate whether the I/O subsystem is overloaded or has a configuration problem. See the PAGEIOLATCH_SH wait type for more information.
Known occurrences in SQL Server (list number matches call stack list):
- Waiting for a file read to complete during a bulk load
- Waiting for a bulk insert stream to close during a bulk load
And other similar call stacks.
Abbreviated call stacks (list number matches known occurrences list):
- SOS_Task::PostWait+6e
EventInternal<SuspendQueueSLock>::Wait+210
CStreamBuf::WaitIoCompletion+11e
CImportStream::SwitchBuffer+493
CImpImportProvider::GetRowsetPtr+82d
CreateInprocProvider+35a
CBcpImport::InitForOpenRowset+1c0
CreateBulkRowset+c9
COledbRangeStreamBulk::GetRowset+27
CQScanRmtBaseNew::OpenHelper+76
CQueryScan::StartupQuery+1e0
CXStmtQuery::SetupQueryScanAndExpression+19f
CXStmtQuery::InitForExecute+1f
CXStmtQuery::ErsqExecuteQuery+2fb
CXStmtSelect::XretExecute+28a
CMsqlExecContext::ExecuteStmts<1,1>+352
CMsqlExecContext::FExecute+878
CSQLSource::Execute+7d3 - XeSosPkg::wait_completed::Publish+0x1dc
SOS_Task::PostWait+0x6f
WaitableBase::Wait+0x19c
CStreamBuf::WaitIoCompletion+0x118
CImportStream::~CImportStream+0xec
CImportStream::`scalar deleting destructor’+0xe
CImportRowset::~CImportRowset+0x111
CImportRowset::Release+0x20
COledbRangeStreamBulk::DoNormalize+0x15e
COledbRange::Normalize+0x152
CAlgTableMetadata::FPartialBind+0x45f
CAlgTableMetadata::Bind+0x31b
CRelOp_Get::BindTree+0x61c
COptExpr::BindTree+0x85
CRelOp_QuerySpec::BindTree+0x1ea
COptExpr::BindTree+0x85
CRelOp_Insert::BindTree+0xdf
COptExpr::BindTree+0x85
CRelOp_DMLQuery::BindTree+0x76
COptExpr::BindTree+0x85
CRelOp_Query::FAlgebrizeQuery+0x4e7
CStmtBulkInsert::FBind+0x44