BACKUP LOG MyImportantDB WITH NO_LOG
BACKUP LOG MyImportantDB WITH TRUNCATE_ONLY
DUMP TRAN MyImportantDB WITH NO_LOG
Just an additional point. All three of those were deprecated in SQL 2005 and removed in SQL 2008. From 2008 onwards the only way to remove inactive entries from the log is to either back it up or set the database to simple recovery.
BACKUP LOG AdventureWorks WITH NO_LOG
Msg 3032, Level 16, State 2, Line 1
One or more of the options (no_log) are not supported for this statement. Review the documentation for supported options.
BACKUP LOG AdventureWorks WITH TRUNCATE_ONLY
Msg 155, Level 15, State 1, Line 1
'TRUNCATE_ONLY' is not a recognized BACKUP option.
DUMP TRAN AdventureWorks WITH NO_LOG
Msg 156, Level 15, State 1, Line 1
Incorrect syntax near the keyword 'TRAN'.
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
We walk in the dark places no others will enter
We stand on the bridge and no one may pass