An internal component named the SQLOS creates node structures that mimic hardware processor locality. These structures can be changed by using soft-NUMA to create custom node layouts.
The following table provides information about these nodes.
NOTE: To call this from Azure SQL Data Warehouse or Parallel Data Warehouse, use the name sys.dm_pdw_nodes_os_nodes.
|Column name||Data type||Description|
|node_id||smallint||ID of the node.|
|node_state_desc||nvarchar(256)||Description of the node state. Values are displayed with the mutually exclusive values first, followed by the combinable values. For example:
Online, Thread Resources Low, Lazy Preemptive
There are four mutually exclusive node_state_desc values. They are listed below with their descriptions.
ONLINE: Node is online
OFFLINE: Node is offline
IDLE: Node has no pending work requests, and has entered an idle state.
IDLE_READY: Node has no pending work requests, and is ready to enter an idle state.
There are five combinable node_state_desc values, listed below with their descriptions.
DAC: This node is reserved for the Dedicated Administrative Connection.
THREAD_RESOURCES_LOW: No new threads can be created on this node because of a low-memory condition.
HOT ADDED: Indicates the nodes were added in response to a hot add CPU event.
|memory_object_address||varbinary(8)||Address of memory object associated with this node. One-to-one relation to sys.dm_os_memory_objects.memory_object_address.|
|memory_clerk_address||varbinary(8)||Address of memory clerk associated with this node. One-to-one relation to sys.dm_os_memory_clerks.memory_clerk_address.|
|io_completion_worker_address||varbinary(8)||Address of worker assigned to IO completion for this node. One-to-one relation to sys.dm_os_workers.worker_address.|
|memory_node_id||smallint||ID of the memory node this node belongs to. Many-to-one relation to sys.dm_os_memory_nodes.memory_node_id.|
|cpu_affinity_mask||bigint||Bitmap identifying the CPUs this node is associated with.|
|online_scheduler_count||smallint||Number of online schedulers that aremanaged by this node.|
|idle_scheduler_count||smallint||Number of online schedulers that have no active workers.|
|active_worker_count||int||Number of workers that are active on all schedulers managed by this node.|
|avg_load_balance||int||Average number of tasks per scheduler on this node.|
|timer_task_affinity_mask||bigint||Bitmap identifying the schedulers that can have timer tasks assigned to them.|
|permanent_task_affinity_mask||bigint||Bitmap identifying the schedulers that can have permanent tasks assigned to them.|
|resource_monitor_state||bit||Each node has one resource monitor assigned to it. The resource monitor can be running or idle. A value of 1 indicates running, a value of 0 indicates idle.|
|online_scheduler_mask||bigint||Identifies the process affinity mask for this node.|
|processor_group||smallint||Identifies the group of processors for this node.|
|pdw_node_id||int||The identifier for the node that this distribution is on.
Applies to: Azure SQL Data Warehouse, Parallel Data Warehouse
On SQL Server, requires
VIEW SERVER STATE permission.
On SQL Database Premium Tiers, requires the
VIEW DATABASE STATE permission in the database. On SQL Database Standard and Basic Tiers, requires the Server admin or an Azure Active Directory admin account.