System Administrators can truncate the transaction log when Adaptive Server performs an automatic checkpoint.
To set the trunc log on chkpt database option, which will truncate the transaction log if it consists of 50 or more rows when an automatic checkpoint occurs, execute this command from the master database:
sp_dboption database_name, "trunc log on chkpt", true
This option is not suitable for production environments because it does not make a copy of the transaction log before truncating it. Use trunc log on chkpt only for:
Databases whose transaction logs cannot be backed up because they are not on a separate segment
Test databases for which current backups are not important
If you leave the trunc log on chkpt option set to off (the default condition), the transaction log continues to grow until you truncate it with the dump transaction command.
To protect your log from running out of space, you should design your last-chance threshold procedure to dump the transaction log. For more information about threshold procedures, see Chapter 29, “Managing Free Space with Thresholds.”