Rediģēt

Kopīgot, izmantojot

sys.dm_pdw_request_steps (Transact-SQL)

  • Raksts

Applies to: Azure Synapse Analytics Analytics Platform System (PDW)

Holds information about all steps that compose a given request or query in Azure Synapse Analytics. It lists one row per query step.

Note

This syntax is not supported by serverless SQL pool in Azure Synapse Analytics.

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.
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.
plan_node_id int The node ID corresponding to the operator ID of that step in the execution plan. None
operation_type nvarchar(35) Type of operation represented by this step. DMS query plan operations: PartitionMoveOperation, MoveOperation, BroadcastMoveOperation, ShuffleMoveOperation, TrimMoveOperation, CopyOperation, DistributeReplicatedTableMoveOperation

SQL query plan operations: ReturnOperation, 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 Analytics Platform System (PDW) 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 undergoes. AllNodes, AllDistributions, AllComputeNodes, ComputeNode, Distribution, SubsetNodes, SubsetDistributions, Unspecified
location_type nvarchar(32) Specifies 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. NULL if no error occurred. The request_id can be matched with the request_id in sys.dm_pdw_errors to view all of the listed errors for that specific request_id.
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.
end_time datetime Time at which this step completed execution, was canceled, 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 continues to be the maximum value. This condition generates 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 don't operate on data.
estimated_rows bigint Total number of rows of work calculated during query compilation. The number of rows estimated by the step. Greater than or equal to zero for data operation steps. -1 for steps that don't 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 4,000 characters.

For information about the maximum rows retained by this view, see Capacity limits.

Related content