sys.dm_exec_distributed_requests (Transact-SQL)
Applies to: 
SQL Server 2016 (13.x) and later versions
Holds information about all requests currently or recently active in PolyBase queries. It lists one row per request/query.
Based on session and request ID, a user can then retrieve the actual distributed requests generated to be executed - via sys.dm_exec_distributed_requests. For example, a query involving regular SQL and external SQL tables will be decomposed into various statements/requests executed across the various compute nodes. To track the distributed steps across all compute nodes, we introduce a 'global' execution ID which can be used to track all operations on the compute nodes associated with one particular request and operator, respectively.
| Column Name | Data Type | Description | Range |
|---|---|---|---|
| sql_handle | varbinary(64) | Key for this view. Unique numeric id associated with the request. | Unique across all requests in the system. |
| execution_id | nvarchar(32 | Unique numeric id associated with the session in which this query was run. | |
| status | nvarchar(32 | Current status of the request. | 'Pending', 'Authorizing', 'AcquireSystemResources', 'Initializing', 'Plan', 'Parsing', 'AcquireResources', 'Running', 'Cancelling', 'Complete', 'Failed', 'Cancelled'. |
| error_id | nvarchar(36) | Unique id of the error associated with the request, if any. | Set to NULL if no error occurred. |
| start_time | datetime | Time at which the request execution was started. | 0 for queued requests; otherwise, valid datetime smaller or equal to current time. |
| end_time | datetime | Time at which the engine completed compiling the request. | NULL for queued or active requests; otherwise, a valid datetime smaller or equal to current time. |
| total_elapsed_time | int | Time elapsed in execution since the request was started, in milliseconds. | Between 0 and the difference between start_time and end_time.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. |
See Also
PolyBase troubleshooting with dynamic management views
Dynamic Management Views and Functions (Transact-SQL)
Database Related Dynamic Management Views (Transact-SQL)