sys.dm_pdw_request_steps (Transact-SQL)

Applies to: yesAzure Synapse Analytics yesParallel Data Warehouse

Holds information about all steps that compose a given request or query in SQL Data Warehouse. It lists one row per query step.

Column Name Data Type Description Range
request_id nvarchar(32) request_id and step_index make up the key for this view.

Unique numeric id associated with the request.
See request_id in sys.dm_pdw_exec_requests (Transact-SQL).
step_index int request_id and step_index make up the key for this view.

The position of this step in the sequence of steps that make up the request.
0 to (n-1) for a request with n steps.
operation_type nvarchar(35) Type of operation represented by this step. DMS query plan operations: 'ReturnOperation', 'PartitionMoveOperation', 'MoveOperation', 'BroadcastMoveOperation', 'ShuffleMoveOperation', 'TrimMoveOperation', 'CopyOperation', 'DistributeReplicatedTableMoveOperation'

SQL query plan operations: 'OnOperation', 'RemoteOperation'

Other query plan operations: 'MetaDataCreateOperation', 'RandomIDOperation'

External operations for reads: 'HadoopShuffleOperation', 'HadoopRoundRobinOperation', 'HadoopBroadcastOperation'

External operations for MapReduce: 'HadoopJobOperation', 'HdfsDeleteOperation'

External operations for writes: 'ExternalExportDistributedOperation', 'ExternalExportReplicatedOperation', 'ExternalExportControlOperation'

For more information, see "Understanding Query Plans" in the Parallel Data Warehouse product documentation.

A query plan can also be affected by the database settings. Check ALTER DATABASE SET options for details.
distribution_type nvarchar(32) Type of distribution this step will undergo. 'AllNodes', 'AllDistributions', 'AllComputeNodes', 'ComputeNode', 'Distribution', 'SubsetNodes', 'SubsetDistributions', 'Unspecified'
location_type nvarchar(32) Where the step is running. 'Compute', 'Control', 'DMS'
status nvarchar(32) Status of this step. Pending, Running, Complete, Failed, UndoFailed, PendingCancel, Cancelled, Undone, Aborted
error_id nvarchar(36) Unique id of the error associated with this step, if any. See error_id of sys.dm_pdw_errors (Transact-SQL). NULL if no error occurred.
start_time datetime Time at which the step started execution. Smaller or equal to current time and larger or equal to end_compile_time of the query to which this step belongs. For more information on queries, see sys.dm_pdw_exec_requests (Transact-SQL).
end_time datetime Time at which this step completed execution, was cancelled, or failed. Smaller or equal to current time and larger or equal to start_time. Set to NULL for steps currently in execution or queued.
total_elapsed_time int Total amount of time the query step has been running, in milliseconds. Between 0 and the difference between end_time and start_time. 0 for queued steps.

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.
row_count bigint Total number of rows changed or returned by this request. The number of rows affected by the step. Greater than or equal to zero for data operation steps. -1 for steps that do not operate on data.
command nvarchar(4000) Holds the full text of the command of this step. Any valid request string for a step. NULL when the operation is of the type MetaDataCreateOperation. Truncated if longer than 4000 characters.

For information about the maximum rows retained by this view, see the Maximum System View Values section in the "Minimum and Maximum Values" in the Parallel Data Warehouse product documentation.

See Also

SQL Data Warehouse and Parallel Data Warehouse Dynamic Management Views (Transact-SQL)