sys-dm-db-log-space-usage-transact-sql.md

title	sys.dm_db_log_space_usage (Transact-SQL) | Microsoft Docs
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ms.date	06/29/2017
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sys.dm_db_log_space_usage (Transact-SQL)

[!INCLUDEtsql-appliesto-ss2012-asdb-xxxx-xxx-md]

Returns space usage information for the transaction log.

Note

All transaction log files are combined.

Column name	Data type	Description
database_id	smallint	Database ID.
total_log_size_in_bytes	bigint	The size of the log
used_log_space_in_bytes	bigint	The occupied size of the log
used_log_space_in_percent	real	The occupied size of the log as a percent of the total log size
log_space_in_bytes_since_last_backup	bigint	The amount of space used since the last log backup Applies to: [!INCLUDEsssql14-md] through [!INCLUDEsscurrent-md], [!INCLUDEssSDS].

Permissions

On [!INCLUDEssNoVersion_md], requires VIEW SERVER STATE permission.
On [!INCLUDEssSDS_md] Premium Tiers, requires the VIEW DATABASE STATE permission in the database. On [!INCLUDEssSDS_md] Standard and Basic Tiers, requires the Server admin or an Azure Active Directory admin account.

Examples

A. Determine the Amount of Free Log Space in tempdb

The following query returns the total free log space in megabytes (MB) available in tempdb.

USE tempdb;  
GO  

SELECT (total_log_size_in_bytes - used_log_space_in_bytes)*1.0/1024/1024 AS [free log space in MB]  
FROM sys.dm_db_log_space_usage;  

See Also

Dynamic Management Views and Functions (Transact-SQL)
Database Related Dynamic Management Views (Transact-SQL)
sys.dm_db_file_space_usage
sys.dm_db_task_space_usage (Transact-SQL)
sys.dm_db_session_space_usage (Transact-SQL)
sys.dm_db_log_info (Transact-SQL)
sys.dm_db_log_stats (Transact-SQL)