sys.dm_pdw_dms_external_work (Transact-SQL)

APPLIES TO: noSQL Server noAzure SQL Database yesAzure SQL Data Warehouse yesParallel Data Warehouse

SQL Data Warehouse system view that holds information about all Data Movement Service (DMS) steps for external operations.

Column Name Data Type Description Range
request_id nvarchar(32) Query that is using this DMS worker.

request_id, step_index, and dms_step_index form the key for this view.
Same as request_id in sys.dm_pdw_exec_requests (Transact-SQL).
step_index int Query step that is invoking this DMS worker.

request_id, step_index, and dms_step_index form the key for this view.
Same as step_index in sys.dm_pdw_request_steps (Transact-SQL).
dms_step_index int Current step in the DMS plan.

request_id, step_index, and dms_step_index form the key for this view.
Same as dms___step_index in sys.dm_pdw_dms_workers (Transact-SQL).
pdw_node_id int Node that is running the DMS worker. Same as node_id in sys.dm_pdw_nodes (Transact-SQL).
type nvarchar(60) Type of external operation this node is running.

FILE SPLIT is an operation on an external Hadoop file that has been split into multiple smaller falls.
'FILE SPLIT'
work_id int The file split ID. Greater than or equal to 0.

Unique per Compute node.
input_name nvarchar(60) String name for the input being read. For a Hadoop file, this is the Hadoop file name.
read_location bigint Offset of read location.
estimated_bytes_processed bigint Number of bytes processed by this worker. Greater than or equal to 0.
length bigint Number of bytes in the file split.

For Hadoop, this is the size of the HDFS block.
User-defined. The default is 64 MB.
status nvarchar(32) State of the worker. Pending, Processing, Done, Failed, Aborted
start_time datetime Time at which execution of this worker started. Greater than or equal to start time of the query step this worker belongs to. See sys.dm_pdw_request_steps (Transact-SQL).
end_time datetime Time at which execution ended, failed, or was cancelled. NULL for ongoing or queued workers. Otherwise, greater than start_time.
total_elapsed_time int Total time spent in execution, in milliseconds. Greater than or equal to 0.

If total_elapsed_time exceeds the maximum value for an integer, total_elapsed_time will continue to be the maximum value. This condition will generate the warning "The maximum value has been exceeded."

The maximum value in milliseconds is equivalent to 24.8 days.

For information about the maximum rows retained by this view, see the Metadata section in the Capacity limits topic.

See Also

System Views (Transact-SQL)