| title | description | author | ms.author | ms.date | ms.service | ms.subservice | ms.topic | f1_keywords | helpviewer_keywords | dev_langs | monikerRange | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
sys.dm_os_memory_objects (Transact-SQL) |
sys.dm_os_memory_objects (Transact-SQL) |
rwestMSFT |
randolphwest |
02/27/2023 |
sql |
system-objects |
reference |
|
|
|
>=aps-pdw-2016||=azuresqldb-current||=azure-sqldw-latest||>=sql-server-2016||>=sql-server-linux-2017||=azuresqldb-mi-current |
[!INCLUDE sql-asdb-asdbmi-asa-pdw]
Returns memory objects that are currently allocated by [!INCLUDEssNoVersion]. You can use sys.dm_os_memory_objects to analyze memory use and to identify possible memory leaks.
Note
To call this from [!INCLUDEssazuresynapse-md] or [!INCLUDEssPDW], use the name sys.dm_pdw_nodes_os_memory_objects. [!INCLUDEsynapse-analytics-od-unsupported-syntax]
| Column name | Data type | Description |
|---|---|---|
| memory_object_address | varbinary(8) | Address of the memory object. Is not nullable. |
| parent_address | varbinary(8) | Address of the parent memory object. Is nullable. |
| pages_allocated_count | int | Applies to: [!INCLUDEsql2008-md] through [!INCLUDEsql2008r2]. Number of pages that are allocated by this object. Is not nullable. |
| pages_in_bytes | bigint | Applies to: [!INCLUDEssSQL11] and later. Amount of memory in bytes that is allocated by this instance of the memory object. Is not nullable. |
| creation_options | int | Internal use only. Is nullable. |
| bytes_used | bigint | Internal use only. Is nullable. |
| type | nvarchar(60) | Type of memory object. This indicates some component that this memory object belongs to, or the function of the memory object. Is nullable. |
| name | varchar(128) | Internal use only. Nullable. |
| memory_node_id | smallint | ID of a memory node that is being used by this memory object. Is not nullable. |
| creation_time | datetime | Internal use only. Is nullable. |
| max_pages_allocated_count | int | Applies to: [!INCLUDEsql2008-md] through [!INCLUDEsql2008r2]. Maximum number of pages allocated by this memory object. Is not nullable. |
| page_size_in_bytes | int | Applies to: [!INCLUDEssSQL11] and later. Size of pages in bytes allocated by this object. Is not nullable. |
| max_pages_in_bytes | bigint | Maximum amount of memory ever used by this memory object. Is not nullable. |
| page_allocator_address | varbinary(8) | Memory address of page allocator. Is not nullable. For more information, see sys.dm_os_memory_clerks (Transact-SQL). |
| creation_stack_address | varbinary(8) | Internal use only. Is nullable. |
| sequence_num | int | Internal use only. Is nullable. |
| partition_type | int | Applies to: [!INCLUDEssSQL16] and later. The type of partition: 0 - Non-partitionable memory object 1 - Partitionable memory object, currently not partitioned 2 - Partitionable memory object, partitioned by NUMA node. In an environment with a single NUMA node this is equivalent to 1. 3 - Partitionable memory object, partitioned by CPU. |
| contention_factor | real | Applies to: [!INCLUDEssSQL16] and later. A value specifying contention on this memory object, with 0 meaning no contention. The value is updated whenever a specified number of memory allocations were made reflecting contention during that period. Applies only to thread-safe memory objects. |
| waiting_tasks_count | bigint | Applies to: [!INCLUDEssSQL16] and later. Number of waits on this memory object. This counter is incremented whenever memory is allocated from this memory object. The increment is the number of tasks currently waiting for access to this memory object. Applies only to thread-safe memory objects. This is a best effort value without a correctness guarantee. |
| exclusive_access_count | bigint | Applies to: [!INCLUDEssSQL16] and later. Specifies how often this memory object was accessed exclusively. Applies only to thread-safe memory objects. This is a best effort value without a correctness guarantee. |
| pdw_node_id | int | Applies to: [!INCLUDEssazuresynapse-md], [!INCLUDEssPDW] The identifier for the node that this distribution is on. |
partition_type, contention_factor, waiting_tasks_count, and exclusive_access_count are not yet implemented in [!INCLUDEsssds].
On [!INCLUDEssNoVersion_md] 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.
Requires VIEW SERVER PERFORMANCE STATE permission on the server.
Memory objects are heaps. They provide allocations that have a finer granularity than those provided by memory clerks. [!INCLUDEssNoVersion] components use memory objects instead of memory clerks. Memory objects use the page allocator interface of the memory clerk to allocate pages. Memory objects do not use virtual or shared memory interfaces. Depending on the allocation patterns, components can create different types of memory objects to allocate regions of arbitrary size.
The typical page size for a memory object is 8 KB. However, incremental memory objects can have page sizes that range from 512 bytes to 8 KB.
Note
Page size is not a maximum allocation. Instead, page size is allocation granularity that is supported by a page allocator and that is implemented by a memory clerk. You can request allocations greater than 8 KB from memory objects.
The following example returns the amount of memory allocated by each memory object type.
SELECT SUM (pages_in_bytes) as 'Bytes Used', type
FROM sys.dm_os_memory_objects
GROUP BY type
ORDER BY 'Bytes Used' DESC;
GO
SQL Server Operating System Related Dynamic Management Views (Transact-SQL)
sys.dm_os_memory_clerks (Transact-SQL)