Log Settings 
The following log settings are possible:
·
You can
mirror the log area.
If you cannot use
hardware-base mirroring for the log area, we
recommend that you use the software-based mirroring setting.
To make this
setting, proceed as described in Log
Mode.
·
You can
decide to do without log backups and
use a non-standard log backup strategy by setting the overwrite mode for the
log area accordingly.
To make this
setting, proceed as described in Overwrite
Mode.
·
In very
special situations, you can deactivate redo log
management temporarily.
To do this, proceed
as described in Activating or
Deactivating Redo Log Management.
The combination of log settings you choose depends on your security requirements.
In production systems, you should aim for the highest possible security standards. In this case, make the following log settings:
· Mirror log area (hardware-based)
· Standard log backup operation (with log backups)
· Redo log management always activated
· Perform data and log backups
If you require a lower level of security for your system, you can decide not to mirror the log area.
Use different log backup operations only if all you require in the event of a database crash is for the system to be restored to the state of an existing data backup .
Deactivating redo log management places the security of your system at serious risk, and should be considered only under exceptional circumstances.