sys.dm_os_nodes (Transact-SQL)
Applies to: 
SQL Server
Azure SQL Database
Azure SQL Managed Instance
Azure Synapse Analytics
Analytics Platform System (PDW)
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.
Note
Starting with SQL Server 2016 (13.x), the SQL Server Database Engine will automatically use soft-NUMA for certain hardware configurations. For more information, see Automatic Soft-NUMA.
The following table provides information about these nodes.
Note
To call this DMV from Azure Synapse Analytics or Analytics Platform System (PDW), use the name sys.dm_pdw_nodes_os_nodes. This syntax is not supported by serverless SQL pool in Azure Synapse Analytics.
| 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.
There are three combinable node_state_desc values, listed below with their descriptions.
|
| 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 are managed 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. |
| cpu_count | int | Number of CPUs available for this node. |
| pdw_node_id | int | The identifier for the node that this distribution is on. Applies to: Azure Synapse Analytics, Analytics Platform System (PDW) |
Permissions
On SQL Server and SQL Managed Instance, requires VIEW SERVER STATE permission.
On SQL Database Basic, S0, and S1 service objectives, and for databases in elastic pools, the server admin account, the Microsoft Entra admin account, or membership in the ##MS_ServerStateReader## server role is required. On all other SQL Database service objectives, either the VIEW DATABASE STATE permission on the database, or membership in the ##MS_ServerStateReader## server role is required.
Permissions for SQL Server 2022 and later
Requires VIEW SERVER PERFORMANCE STATE permission on the server.
See also
SQL Server Operating System Related Dynamic Management Views (Transact-SQL)
Soft-NUMA (SQL Server)