Усечение логов транзакций базы данных MS SQL Server

USE DB_name
BACKUP LOG DB_name to DISK = 'path_to_file_bak';
DBCC SHRINKFILE (Logical_Log_Name, 128)
WAITFOR DELAY '00:00:01'
BACKUP LOG DB_name to DISK = 'path_to_file_bak';
DBCC SHRINKFILE (Logical_Log_Name, 128)
WAITFOR DELAY '00:00:01'
DBCC SHRINKFILE (TSOnline_Log, 128)