DBCC SQLPERF (Transact-SQL)
Applies to: SQL Server (all supported versions) Azure SQL Database Azure SQL Managed Instance
Provides transaction log space usage statistics for all databases. In SQL Server, it can also be used to reset wait and latch statistics.
Applies to: SQL Server 2008 (10.0.x) and later versions, and SQL Database (Preview in some regions)
DBCC SQLPERF ( [ LOGSPACE ] | [ "sys.dm_os_latch_stats" , CLEAR ] | [ "sys.dm_os_wait_stats" , CLEAR ] ) [ WITH NO_INFOMSGS ]
To view Transact-SQL syntax for SQL Server 2014 and earlier, see Previous versions documentation.
Returns the current size of the transaction log and the percentage of log space used for each database. Use this information to monitor the amount of space used in a transaction log.
For more information about space usage information for the transaction log starting with SQL Server 2012 (11.x), see the Remarks section in this topic.
Resets the latch statistics. For more information, see sys.dm_os_latch_stats (Transact-SQL). This option isn't available in SQL Database.
Resets the wait statistics. For more information, see sys.dm_os_wait_stats (Transact-SQL). This option isn't available in SQL Database.
Suppresses all informational messages that have severity levels from 0 through 10.
The following table describes the columns in the result set.
|Database Name||Name of the database for the log statistics displayed.|
|Log Size (MB)||Current size allocated to the log. This value is always smaller than the amount originally allocated for log space because the Database Engine reserves a small amount of disk space for internal header information.|
|Log Space Used (%)||Percentage of the log file currently in use to store transaction log information.|
|Status||Status of the log file. Always 0.|
Starting with SQL Server 2012 (11.x), use the sys.dm_db_log_space_usage DMV instead of
DBCC SQLPERF(LOGSPACE), to return space usage information for the transaction log per database.
The transaction log records each transaction made in a database. For more information, see The Transaction Log (SQL Server) and SQL Server Transaction Log Architecture and Management Guide.
SQL Server requires VIEW SERVER STATE permission on the server to run
DBCC SQLPERF(LOGSPACE). To reset wait and latch statistics requires
ALTER SERVER STATE permission on the server.
SQL Database Premium and Business Critical tiers require the VIEW DATABASE STATE permission in the database. SQL Database Standard, Basic, and General Purpose tiers require the SQL Database admin account. Reset wait and latch statistics aren't supported.
A. Display log space information for all databases
The following example displays
LOGSPACE information for all databases contained in the instance of SQL Server.
DBCC SQLPERF (LOGSPACE); GO
Here is the result set.
Database Name Log Size (MB) Log Space Used (%) Status ------------- ------------- ------------------ ----------- master 3.99219 14.3469 0 tempdb 1.99219 1.64216 0 model 1.0 12.7953 0 msdb 3.99219 17.0132 0 AdventureWorks 19.554688 17.748701 0
B. Reset wait statistics
The following example resets the wait statistics for the instance of SQL Server.
DBCC SQLPERF ("sys.dm_os_wait_stats", CLEAR);