sys.dm_db_task_space_usage (Transact-SQL)

Artikel
05/16/2013

Returns page allocation and deallocation activity by task for the database.

Note

This view is applicable only to the tempdb database.

Column name	Data type	Description
session_id	smallint	Session ID.
request_id	int	Request ID within the session. A request is also called a batch and may contain one or more queries. A session may have multiple requests active at the same time. Each query in the request may start multiple threads (tasks), if a parallel execution plan is used.
exec_context_id	int	Execution context ID of the task. For more information, see sys.dm_os_tasks (Transact-SQL).
database_id	smallint	Database ID.
user_objects_alloc_page_count	bigint	Number of pages reserved or allocated for user objects by this task.
user_objects_dealloc_page_count	bigint	Number of pages deallocated and no longer reserved for user objects by this task.
internal_objects_alloc_page_count	bigint	Number of pages reserved or allocated for internal objects by this task.
internal_objects_dealloc_page_count	bigint	Number of pages deallocated and no longer reserved for internal objects by this task.

Permissions

Requires VIEW SERVER STATE permission on the server.

Remarks

IAM pages are not included in any of the page counts reported by this view.

Page counters are initialized to zero (0) at the start of a request. These values are aggregated at the session level when the request is completed. For more information, see sys.dm_db_session_space_usage (Transact-SQL).

Work table caching, temporary table caching, and deferred drop operations affect the number of pages allocated and deallocated in a specified task.

User Objects

The following objects are included in the user object page counters:

User-defined tables and indexes
System tables and indexes
Global temporary tables and indexes
Local temporary tables and indexes
Table variables
Tables returned in the table-valued functions

Internal Objects

Internal objects are only in tempdb. The following objects are included in the internal object page counters:

Work tables for cursor or spool operations and temporary large object (LOB) storage
Work files for operations such as a hash join
Sort runs

Physical Joins

Physical joins for sys.dm_db_session_task_usage

Relationship Cardinalities

From	To	Relationship
dm_db_task_space_usage.request_id	dm_exec_requests.request_id	One-to-one
dm_db_task_space_usage.session_id	dm_exec_requests.session_id	One-to-one

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