Allocations that are internal to SQL Server use the SQL Server memory manager. Tracking the difference between process memory counters from sys.dm_os_process_memory and internal counters can indicate memory use from external components in the SQL Server memory space.
Memory brokers fairly distribute memory allocations between various components within SQL Server, based on current and projected usage. Memory brokers do not perform allocations. They only track allocations for computing distribution.
The following table provides information about memory brokers.
To call this from Azure SQL Data Warehouse or Parallel Data Warehouse, use the name sys.dm_pdw_nodes_os_memory_brokers.
|Column name||Data type||Description|
|pool_id||int||ID of the resource pool if it is associated with a Resource Governor pool.|
|memory_broker_type||nvarchar(60)||Type of memory broker. There are currently three types of memory brokers in SQL Server, listed below with their descriptions.
MEMORYBROKER_FOR_CACHE : Memory that is allocated for use by cached objects.
MEMORYBROKER_FOR_STEAL : Memory that is stolen from the buffer pool. This memory is not available for reuse by other components until it is freed by the current owner.
MEMORYBROKER_FOR_RESERVE : Memory reserved for future use by currently executing requests.
|allocations_kb||bigint||Amount of memory, in kilobytes (KB), that has been allocated to this type of broker.|
|allocations_kb_per_sec||bigint||Rate of memory allocations in kilobytes (KB) per second. This value can be negative for memory deallocations.|
|predicted_allocations_kb||bigint||Predicted amount of allocated memory by the broker. This is based on the memory usage pattern.|
|target_allocations_kb||bigint||Recommended amount of allocated memory, in kilobytes (KB), that is based on current settings and the memory usage pattern. This broker should grow to or shrink to this number.|
|future_allocations_kb||bigint||Projected number of allocations, in kilobytes (KB), that will be done in the next several seconds.|
|overall_limit_kb||bigint||Maximum amount of memory, in kilobytes (KB), that the the broker can allocate.|
|last_notification||nvarchar(60)||Memory usage recommendation that is based on the current settings and usage pattern. Valid values are as follows:
|pdw_node_id||int||Applies to: Azure SQL Data Warehouse, Parallel Data Warehouse
The identifier for the node that this distribution is on.
On SQL Server, requires
VIEW SERVER STATE permission.
On SQL Database, requires the
VIEW DATABASE STATE permission in the database.