add columns for workload isolation mark internal only

Author: julieMSFT

docs/relational-databases/system-dynamic-management-views/sys-dm-pdw-exec-requests-transact-sql.md

@@ -36,6 +36,8 @@ monikerRange: ">= aps-pdw-2016 || = azure-sqldw-latest || = sqlallproducts-allve
 |command|**nvarchar(4000)**|Holds the full text of the request as submitted by the user.|Any valid query or request text. Queries that are longer than 4000 bytes are truncated.|  
 |resource_class|**nvarchar(20)**|The resource class for this request. See related **concurrency_slots_used** in [sys.dm_pdw_resource_waits &#40;Transact-SQL&#41;](../../relational-databases/system-dynamic-management-views/sys-dm-pdw-resource-waits-transact-sql.md).  For more information on resource classes, see [Resource classes & workload management](https://docs.microsoft.com/azure/sql-data-warehouse/resource-classes-for-workload-management) |Static Resource Classes</br>staticrc10</br>staticrc20</br>staticrc30</br>staticrc40</br>staticrc50</br>staticrc60</br>staticrc70</br>staticrc80</br>            </br>Dynamic Resource Classes</br>SmallRC</br>MediumRC</br>LargeRC</br>XLargeRC|
 |importance|**nvarchar(32)**|The importance setting the request was submitted with. Requests with a lower importance will remain queued in suspended state, if higher importance requests are submitted.  Requests with higher importance will execute before lower importance requests that were submitted earlier.  For more information on importance, see [Workload Importance](https://docs.microsoft.com/azure/sql-data-warehouse/sql-data-warehouse-workload-importance).  |NULL</br>low</br>below_normal</br>normal (default)</br>above_normal</br>high|
+|group_name| |Reserved for internal use.</br>Applies to: Azure SQL Data Warehouse|
+|resource_allocation_percentage| |Reserved for internal use.</br>Applies to: Azure SQL Data Warehouse|
 
  For information about the maximum rows retained by this view, see the Metadata section in the [Capacity limits](/azure/sql-data-warehouse/sql-data-warehouse-service-capacity-limits#metadata) topic.