MySQL Enterprise Backup 4.1 Release Notes
        
        The --exec-when-locked option of
        mysqlbackup lets you specify a command
        (together with the desired command arguments) to run near the
        end of the backup while the database is still locked. This
        command can copy or create additional files in the backup
        directory. For example, you can use this option to back up
        MEMORY tables with the
        mysqldump command, storing the output in the
        backup directory. To delay any redirection or variable
        substitution until the command is executed, enclose the entire
        option value within single quotes.