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sys.dm_tran_version_store_space_usage (Transact-SQL)

  • Άρθρο

Applies to: SQL Server 2016 (13.x) SP 2 and later Azure SQL Database Not supported. Azure Synapse Analytics Not supported. Analytics Platform System (PDW)

Returns a table that displays total space in tempdb used by version store records for each database. sys.dm_tran_version_store_space_usage is efficient and not expensive to run, as it does not navigate through individual version store records, and returns aggregated version store space consumed in tempdb per database.

Each versioned record is stored as binary data, together with some tracking or status information. Similar to records in database tables, version-store records are stored in 8192-byte pages. If a record exceeds 8192 bytes, the record will be split across two different records.

Because the versioned record is stored as binary, there are no problems with different collations from different databases. Use sys.dm_tran_version_store_space_usage to monitor and plan tempdb size based on the version store space usage of databases in a SQL Server instance.

Column name Data type Description
database_id int Database ID of the database.

In Azure SQL Database, the values are unique within a single database or an elastic pool, but not within a logical server.
reserved_page_count bigint Total count of the pages reserved in tempdb for version store records of the database.
reserved_space_kb bigint Total space used in kilobytes in tempdb for version store records of the database.

Permissions

On SQL Server, requires VIEW SERVER STATE permission.

Permissions for SQL Server 2022 and later

Requires VIEW SERVER PERFORMANCE STATE permission on the server.

Examples

The following query can be used to determine space consumed in tempdb, by version store of each database in a SQL Server instance.

SELECT 
  DB_NAME(database_id) as 'Database Name',
  reserved_page_count,
  reserved_space_kb 
FROM sys.dm_tran_version_store_space_usage;

Here's the result set.

Database Name            reserved_page_count reserved_space_kb  
------------------------ -------------------- -----------  
msdb                      0                    0             
AdventureWorks2022        10                   80             
AdventureWorks2022DW      0                    0             
WideWorldImporters        20                   160

See also

Dynamic Management Views and Functions (Transact-SQL)
Transaction Related Dynamic Management Views and Functions (Transact-SQL)