sys.dm_db_log_stats (Transact-SQL)

Applies to: SQL Server 2016 (13.x) SP 2 and later Azure SQL Database Azure SQL Managed Instance

Returns summary level attributes and information on transaction log files of databases. Use this information for monitoring and diagnostics of transaction log health.

Transact-SQL syntax conventions


 sys.dm_db_log_stats ( database_id )


database_id | NULL | DEFAULT

Is the ID of the database. database_id is int. Valid inputs are the ID number of a database, NULL, or DEFAULT. The default is NULL. NULL and DEFAULT are equivalent values in the context of current database.
The built-in function DB_ID can be specified. When using DB_ID without specifying a database name, the compatibility level of the current database must be 90 or greater.

Tables Returned

Column name Data type Description
database_id int Database ID.

In Azure SQL Database, the values are unique within a single database or an elastic pool, but not within a logical server.
recovery_model nvarchar(60) Recovery model of the database. Possible values include:
log_min_lsn nvarchar(24) Current start log sequence number (LSN) in the transaction log.
log_end_lsn nvarchar(24) log sequence number (LSN) of the last log record in the transaction log.
current_vlf_sequence_number bigint Current virtual log file (VLF) sequence number at the time of execution.
current_vlf_size_mb float Current virtual log file (VLF) size in MB.
total_vlf_count bigint Total number of virtual log files (VLFs) in the transaction log.
total_log_size_mb float Total transaction log size in MB.
active_vlf_count bigint Total number of active virtual log files (VLFs) in the transaction log.
active_log_size_mb float Total active transaction log size in MB.
log_truncation_holdup_reason nvarchar(60) Log truncation holdup reason. The value is same as log_reuse_wait_desc column of sys.databases. (For more detailed explanations of these values, see The Transaction Log).
Possible values include:
log_backup_time datetime Last transaction log backup time.
log_backup_lsn nvarchar(24) Last transaction log backup log sequence number (LSN).
log_since_last_log_backup_mb float Log size in MB since last transaction log backup log sequence number (LSN).
log_checkpoint_lsn nvarchar(24) Last checkpoint log sequence number (LSN).
log_since_last_checkpoint_mb float Log size in MB since last checkpoint log sequence number (LSN).
log_recovery_lsn nvarchar(24) Recovery log sequence number (LSN) of the database. If log_recovery_lsn occurs before the checkpoint LSN, log_recovery_lsn is the oldest active transaction LSN, otherwise log_recovery_lsn is the checkpoint LSN.
log_recovery_size_mb float Log size in MB since log recovery log sequence number (LSN).
recovery_vlf_count bigint Total number of virtual log files (VLFs) to be recovered, if there was failover or server restart.


When running sys.dm_db_log_stats against a database that is participating in an Availability Group as a secondary replica, only a subset of the fields described above will be returned. Currently, only database_id, recovery_model, and log_backup_time will be returned when run against a secondary database.


Requires the VIEW SERVER STATE permission in the database.

Permissions for SQL Server 2022 and later

Requires VIEW SERVER PERFORMANCE STATE permission on the server.


A. Determining databases in a SQL Server instance with high number of VLFs

The following query returns the databases with more than 100 VLFs in the log files. Large numbers of VLFs can affect the database startup, restore, and recovery time.

SELECT name AS 'Database Name', total_vlf_count AS 'VLF count' 
FROM sys.databases AS s
CROSS APPLY sys.dm_db_log_stats(s.database_id) 
WHERE total_vlf_count  > 100;

B. Determining databases in a SQL Server instance with transaction log backups older than 4 hours

The following query determines the last log backup times for the databases in the instance.

SELECT name AS 'Database Name', log_backup_time AS 'last log backup time' 
FROM sys.databases AS s
CROSS APPLY sys.dm_db_log_stats(s.database_id); 

See Also

Dynamic Management Views and Functions (Transact-SQL)
Database Related Dynamic Management Views (Transact-SQL)
sys.dm_db_log_space_usage (Transact-SQL)
sys.dm_db_log_info (Transact-SQL)