Setting this value to 1 (on, true, yes) causes the transaction management system to assume that the log file is actually a device, rather than a file. This means that a special device locking method will be used on the log file. It also guarantees that the log file will be opened "append" and that no seeks will be performed on it. This allows for the use of a tape device for the log file on many systems. The default setting is 0 (off, false, no). See Device Locking Under UNIX for more information.