sys.dm_resource_governor_workload_groups_history_ex (Azure SQL Database)

Applies to: YesAzure SQL Database YesAzure 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.

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;

See Also