sys.dm_resource_governor_workload_groups_history_ex (Azure SQL Database)
Applies to: 
Azure SQL Database
Azure SQL Managed Instance
Each row represents a periodic snapshot of workload group statistics in Azure SQL Database. A snapshot is taken when the database engine starts, and every few seconds thereafter. The interval between the current and the previous snapshot may vary, and is provided in the duration_ms column. The latest available snapshots are returned, up to 128 snapshots for each workload group.
| Column name | Data type | Description |
|---|---|---|
| pool_id | int | ID of the resource pool. Is not nullable. |
| group_id | int | ID of the workload group. Is not nullable. |
| name | nvarchar(256) | Name of the workload group. Is not nullable. |
| snapshot_time | datetime | Datetime of the resource group stats snapshot taken. |
| duration_ms | int | Duration between current and previous snapshot. |
| active_worker_count | int | Total workers in current snapshot. |
| active_request_count | int | Current request count. Is not nullable. |
| active_session_count | int | Total active sessions in current snapshot. |
| total_request_count | bigint | Cumulative count of completed requests in the workload group. Is not nullable. |
| delta_request_count | int | Count of completed requests in the workload group since last snapshot. Is not nullable. |
| total_cpu_usage_ms | bigint | Cumulative CPU usage, in milliseconds, by this workload group. Is not nullable. |
| delta_cpu_usage_ms | int | CPU usage in milliseconds since last snapshot. Is not nullable. |
| delta_cpu_usage_preemptive_ms | int | Preemptive win32 calls not govern by SQL CPU RG, since last snapshot. |
| delta_reads_reduced_memgrant_count | int | The count of memory grants that reached the maximum query size limit since last snapshot. Is not nullable. |
| reads_throttled | int | Total number of reads throttled. |
| delta_reads_queued | int | The total read IOs enqueued since last snapshot. Is nullable. Null if the resource group is not governed for IO. |
| delta_reads_issued | int | The total read IOs issued since last snapshot. Is nullable. Null if the resource group is not governed for IO. |
| delta_reads_completed | int | The total read IOs completed since last snapshot. Is not nullable. |
| delta_read_bytes | bigint | The total number of bytes read since last snapshot. Is not nullable. |
| delta_read_stall_ms | int | Total time (in milliseconds) between read IO arrival and completion since last snapshot. Is not nullable. |
| delta_read_stall_queued_ms | int | Total time (in milliseconds) between read IO arrival and issue since last snapshot. Is nullable. Null if the resource group is not governed for IO. Non-zero delta_read_stall_queued_ms means IO is being affected by RG . |
| delta_writes_queued | int | The total write IOs enqueued since last snapshot. Is nullable. Null if the resource group is not governed for IO. |
| delta_writes_issued | int | The total write IOs issued since last snapshot. Is nullable. Null if the resource group is not governed for IO. |
| delta_writes_completed | int | The total write IOs completed since last snapshot. Is not nullable. |
| delta_writes_bytes | bigint | The total number of bytes written since last snapshot. Is not nullable. |
| delta_write_stall_ms | int | Total time (in milliseconds) between write IO arrival and completion since last snapshot. Is not nullable. |
| delta_background_writes | int | The total writes performed by background tasks since last snapshot. |
| delta_background_write_bytes | bigint | The total write size performed by background tasks since last snapshot, in bytes. |
| delta_log_bytes_used | bigint | Log used since last snapshot in bytes. |
| delta_log_temp_db_bytes_used | bigint | Tempdb log used since last snapshot in bytes. |
| delta_query_optimizations | bigint | The count of query optimizations in this workload group since last snapshot. Is not nullable. |
| delta_suboptimal_plan_generations | bigint | The count of suboptimal plan generations that occurred in this workload group due to memory pressure since last snapshot. Is not nullable. |
| max_memory_grant_kb | bigint | Maximum memory grant for the group in KB. |
| max_request_cpu_msec | bigint | Maximum CPU usage, in milliseconds, for a single request. Is not nullable. |
| max_concurrent_request | int | Current setting for the maximum number of concurrent requests. Is not nullable. |
| max_io | int | Maximum IO limit for the group. |
| max_global_io | int | Identified for informational purposes only. Not supported. Future compatibility is not guaranteed. |
| max_queued_io | int | Identified for informational purposes only. Not supported. Future compatibility is not guaranteed. |
| max_log_rate_kb | bigint | Maximum log rate (kilo-bytes per sec) at resource group level. |
| max_session | int | Session limit for the group. |
| max_worker | int | Worker limit for the group. |
| active_outbound_connection_worker_count | int | Total outbound connection workers in current snapshot. |
| max_outbound_connection_worker | int | Outbound connection worker limit for the group. |
| max_outbound_connection_worker_percent | decimal(5,2) | Maximum concurrent outbound connection workers (requests) in percentage based on the limit of the group. |
Permissions
This view requires VIEW SERVER STATE permission.
Remarks
Users can access this dynamic management view to monitor near real time resource consumption for user workload pool as well as system internal pools of Azure SQL Database instance.
Important
Most of the data surfaced by this DMV is intended for internal consumption and is subject to change.
Examples
The following example returns maximum log rate data and consumption at each snapshot by user pool:
SELECT snapshot_time,
name,
max_log_rate_kb,
delta_log_bytes_used
FROM sys.dm_resource_governor_workload_groups_history_ex
WHERE name LIKE 'User%'
ORDER BY snapshot_time DESC;