dump transaction with truncate_only and dump transaction with no_log remove transactions from the log without making a backup copy. To ensure recoverability, dump the database each time you run either command because of lack of disk space. You cannot copy the transaction log until you have done so. See “Using the special dump transaction options” for more information.
If the trunc log on chkpt database option is set to true, and the transaction log contains 50 rows or more, Adaptive Server truncates the log when an automatic checkpoint occurs. If this happens, you must dump the entire database—not the transaction log—to ensure recoverability.
