sys.dm_os_memory_pools (Transact-SQL)
Applies to: 
SQL Server
Azure SQL Database
Azure SQL Managed Instance
Azure Synapse Analytics
Analytics Platform System (PDW)
Returns a row for each object store in the instance of SQL Server. You can use this view to monitor cache memory use and to identify bad caching behavior
Note
To call this from Azure Synapse Analytics or Analytics Platform System (PDW), use the name sys.dm_pdw_nodes_os_memory_pools. This syntax is not supported by serverless SQL pool in Azure Synapse Analytics.
| Column name | Data type | Description |
|---|---|---|
| memory_pool_address | varbinary(8) | Memory address of the entry that represents the memory pool. Is not nullable. |
| pool_id | int | ID of a specific pool within a set of pools. Is not nullable. |
| type | nvarchar(60) | Type of object pool. Is not nullable. For more information, see sys.dm_os_memory_clerks (Transact-SQL). |
| name | nvarchar(256) | System-assigned name of this memory object. Is not nullable. |
| max_free_entries_count | bigint | Maximum number of free entries that a pool can have. Is not nullable. |
| free_entries_count | bigint | Number of free entries currently in the pool. Is not nullable. |
| removed_in_all_rounds_count | bigint | Number of entries removed from the pool since the instance of SQL Server was started. Is not nullable. |
| pdw_node_id | int | Applies to: Azure Synapse Analytics, Analytics Platform System (PDW) The identifier for the node that this distribution is on. |
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.
Remarks
SQL Server components sometimes use a common pool framework to cache homogeneous, stateless types of data. The pool framework is simpler than cache framework. All entries in the pools are considered equal. Internally, pools are memory clerks and can be used in places where memory clerks are used.
See also
SQL Server Operating System Related Dynamic Management Views (Transact-SQL)