NOLOGGING / UNRECOVERABLE operations may be possible for certain operations to reduce the overall rate of redo generation. Use of the /*+ APPEND */ SQL Hint should be used on all UPDATE/INSERT statements that have transient data.
• RAW devices can be faster file system files
• RAID5 is not a good candidate for redo log members
• Redo log members must be on high speed disks
• Redo log members should be on disks with little/no IO activity from other sources (including low activity from other sources against the same disk controller)