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sys.dm_resource_governor_resource_pools (Transact-SQL)

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Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance Azure Synapse Analytics Analytics Platform System (PDW)

Returns information about the current resource pool state, the current configuration of resource pools, and resource pool statistics.

Note

To call this from Azure Synapse Analytics or Analytics Platform System (PDW), use the name sys.dm_pdw_nodes_resource_governor_resource_pools. This syntax is not supported by serverless SQL pool in Azure Synapse Analytics.

Column name Data type Description
pool_id int The ID of the resource pool. Not nullable.
name sysname The name of the resource pool. Not nullable.
statistics_start_time datetime The time when statistics was reset for this pool. Not nullable.
total_cpu_usage_ms bigint The cumulative CPU usage in milliseconds since the Resource Governor statistics were reset. Not nullable.
cache_memory_kb bigint The current total cache memory usage in kilobytes. Not nullable.
compile_memory_kb bigint The current total stolen memory usage in kilobytes (KB). Most this usage would be for compile and optimization, but it can also include other memory users. Not nullable.
used_memgrant_kb bigint The current total used (stolen) memory from memory grants. Not nullable.
total_memgrant_count bigint The cumulative count of memory grants in this resource pool. Not nullable.
total_memgrant_timeout_count bigint The cumulative count of memory grant time-outs in this resource pool. Not nullable.
active_memgrant_count int The current count of memory grants. Not nullable.
active_memgrant_kb bigint The sum, in kilobytes (KB), of current memory grants. Not nullable.
memgrant_waiter_count int The count of queries currently pending on memory grants. Not nullable.
max_memory_kb bigint The maximum amount of memory, in kilobytes, that the resource pool can have. This is based on the current settings and server state. Not nullable.
used_memory_kb bigint The amount of memory used, in kilobytes, for the resource pool. Not nullable.
target_memory_kb bigint The target amount of memory, in kilobytes, the resource pool is trying to attain. This is based on the current settings and server state. Not nullable.
out_of_memory_count bigint The number of failed memory allocations in the pool since the Resource Governor statistics were reset. Not nullable.
min_cpu_percent int The current configuration for the guaranteed average CPU bandwidth for all requests in the resource pool when there's CPU contention. Not nullable.
max_cpu_percent int The current configuration for the maximum average CPU bandwidth allowed for all requests in the resource pool when there's CPU contention. Not nullable.
min_memory_percent int The current configuration for the guaranteed amount of memory for all requests in the resource pool when there's memory contention. This isn't shared with other resource pools. Not nullable.
max_memory_percent int The current configuration for the percentage of total server memory that can be used by requests in this resource pool. Not nullable.
cap_cpu_percent int Hard cap on the CPU bandwidth that all requests in the resource pool receive. Limits the maximum CPU bandwidth level to the specified level. The allowed range for value is from 1 through 100. Not nullable.

Applies to: SQL Server 2012 (11.x) and later versions
min_iops_per_volume int The minimum I/O per second (IOPS) per disk volume setting for this Pool. Nullable. NULL if the resource pool isn't governed for I/O. That is, the Resource Pool MIN_IOPS_PER_VOLUME and MAX_IOPS_PER_VOLUME settings are 0.

Applies to: SQL Server 2014 (12.x) and later versions
max_iops_per_volume int The maximum I/O per second (IOPS) per disk volume setting for this Pool. Nullable. NULL if the resource pool isn't governed for I/O. That is, the Resource Pool MIN_IOPS_PER_VOLUME and MAX_IOPS_PER_VOLUME settings are 0.

Applies to: SQL Server 2014 (12.x) and later versions
read_io_queued_total int The total read I/Os enqueued since the Resource Governor was reset. Nullable. NULL if the resource pool isn't governed for I/O. That is, the Resource Pool MIN_IOPS_PER_VOLUME and MAX_IOPS_PER_VOLUME settings are 0.

Applies to: SQL Server 2014 (12.x) and later versions
read_io_issued_total int The total read I/Os issued since the Resource Governor statistics were reset. Nullable. NULL if the resource pool isn't governed for I/O. That is, the Resource Pool MIN_IOPS_PER_VOLUME and MAX_IOPS_PER_VOLUME settings are 0.

Applies to: SQL Server 2014 (12.x) and later versions
read_io_completed_total int The total read I/Os completed since the Resource Governor statistics were reset. Not nullable.
read_io_throttled_total int The total read I/Os throttled since the Resource Governor statistics were reset. Nullable. NULL if the resource pool isn't governed for I/O. That is, the Resource Pool MIN_IOPS_PER_VOLUME and MAX_IOPS_PER_VOLUME settings are 0.

Applies to: SQL Server 2014 (12.x) and later versions
read_bytes_total bigint The total number of bytes read since the Resource Governor statistics were reset. Not nullable.

Applies to: SQL Server 2014 (12.x) and later versions
read_io_stall_total_ms bigint Total time (in milliseconds) between read I/O arrival and completion. Not nullable.

Applies to: SQL Server 2014 (12.x) and later versions
read_io_stall_queued_ms bigint Total time (in milliseconds) between read I/O arrival and issue. Nullable. NULL if the resource pool isn't governed for I/O. That is, the Resource Pool MIN_IOPS_PER_VOLUME and MAX_IOPS_PER_VOLUME settings are 0.

To determine if the I/O setting for the pool is causing latency, subtract read_io_stall_queued_ms from read_io_stall_total_ms.

Applies to: SQL Server 2014 (12.x) and later versions
write_io_queued_total int The total write I/Os enqueued since the Resource Governor statistics were reset. Nullable. NULL if the resource pool isn't governed for I/O. That is, the Resource Pool MIN_IOPS_PER_VOLUME and MAX_IOPS_PER_VOLUME settings are 0.

Applies to: SQL Server 2014 (12.x) and later versions
write_io_issued_total int The total write I/Os issued since the Resource Governor statistics were reset. Nullable. NULL if the resource pool isn't governed for I/O. That is, the Resource Pool MIN_IOPS_PER_VOLUME and MAX_IOPS_PER_VOLUME settings are 0.

Applies to: SQL Server 2014 (12.x) and later versions
write_io_completed_total int The total write I/Os completed since the Resource Governor statistics were reset. Not nullable.

Applies to: SQL Server 2014 (12.x) and later versions
write_io_throttled_total int The total write I/Os throttled since the Resource Governor statistics were reset. Not nullable.

Applies to: SQL Server 2014 (12.x) and later versions
write_bytes_total bigint The total number of bytes written since the Resource Governor statistics were reset. Not nullable.

Applies to: SQL Server 2014 (12.x) and later versions
write_io_stall_total_ms bigint Total time (in milliseconds) between write I/O arrival and completion. Not nullable.

Applies to: SQL Server 2014 (12.x) and later versions
write_io_stall_queued_ms bigint Total time (in milliseconds) between write I/O arrival and issue. Nullable. NULL if the resource pool isn't governed for I/O. That is, the Resource Pool MIN_IOPS_PER_VOLUME and MAX_IOPS_PER_VOLUME settings are 0.

This is the delay introduced by I/O Resource Governance.

Applies to: SQL Server 2014 (12.x) and later versions
io_issue_violations_total int Total I/O issue violations. That is, the number of times when the rate of I/O issue was lower than the reserved rate. Nullable. NULL if the resource pool isn't governed for I/O. That is, the Resource Pool MIN_IOPS_PER_VOLUME and MAX_IOPS_PER_VOLUME settings are 0.

Applies to: SQL Server 2014 (12.x) and later versions
io_issue_delay_total_ms bigint Total time (in milliseconds) between the scheduled issue and actual issue of I/O. Nullable. NULL if the resource pool isn't governed for I/O. That is, the Resource Pool MIN_IOPS_PER_VOLUME and MAX_IOPS_PER_VOLUME settings are 0.

Applies to: SQL Server 2014 (12.x) and later versions
io_issue_ahead_total_ms bigint Internal use only.

Applies to: SQL Server 2016 (13.x) and later versions
reserved_io_limited_by_volume_total bigint Internal use only.

Applies to: SQL Server 2016 (13.x) and later versions
io_issue_delay_non_throttled_total_ms bigint Total time (in milliseconds) between the scheduled issue and actual issue of a non-throttled I/O.

Applies to: SQL Server 2016 (13.x) and later versions
total_cpu_delayed_ms bigint Total time (in milliseconds) between a runnable worker yields, and the operating system gives back control to another runnable worker in the Database Engine. This could be the Idle worker.

Applies to: SQL Server 2016 (13.x) and later versions
total_cpu_active_ms bigint Total active CPU time (in milliseconds).

Applies to: SQL Server 2016 (13.x) and later versions
total_cpu_violation_delay_ms bigint Total CPU violation delays (in milliseconds). That is, total CPU time delay that was lower than the minimum guaranteed delay between a runnable worker yields, and the operating system gives back control to another runnable worker in the Database Engine.

Applies to: SQL Server 2016 (13.x) and later versions
total_cpu_violation_sec bigint Total CPU violations (in seconds). That is, total time accrued when a CPU time violation was in-flight.

Applies to: SQL Server 2016 (13.x) and later versions
total_cpu_usage_preemptive_ms bigint Total CPU time used while in preemptive mode scheduling for the workload group (in milliseconds). Not nullable.

To execute code that is outside the Database Engine (for example, extended stored procedures and distributed queries), a thread has to execute outside the control of the non-preemptive scheduler. To do this, a worker switches to preemptive mode.

Applies to: SQL Server 2016 (13.x) and later versions
max_vcores decimal(5,2) The current configuration for the maximum average CPU bandwidth allowed for all requests in the resource pool when there's CPU contention. In unit of vCores.

Applies to: Azure SQL Database and Azure SQL Managed Instance
total_cpu_usage_actual_ms bigint Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.
pdw_node_id int` The identifier for the node that this distribution is on.

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

Remarks

Resource Governor workload groups and Resource Governor resource pools have a many-to-one mapping. As a result, many of the resource pool statistics are derived from the workload group statistics.

This dynamic management view shows the in-memory configuration. To see the stored configuration metadata, use the sys.resource_governor_resource_pools catalog view.

Permissions

Requires VIEW SERVER STATE permission.

Permissions for SQL Server 2022 and later

Requires VIEW SERVER PERFORMANCE STATE permission on the server.

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