Rman backup & Recovery for a datawarehouse noarchivelog mode

[oracbase]

Hi,

I need some help on RMAN backup & recovery strategy for a 300GB datawarehouse running Oracle 9i R2.

Our datawarehouse cannot turn on archiving due to performance issues.
We need a faster backup strategy, that is why I am exploring RMAN B&R.
2 concerns our application team have raised regarding the new backup strategy:
1) need less down time, faster backup
2) ability to restore the database to the required date.

My RMAN backup strategy is:
- Sunday (cumulative incremental level 0)
- Mon - Tue (cumulative incremental level 2)
- Wed (cumulative incremental level 1)
- Thur - Sat (cumulative incremental level 2)
(currently, rman backup to disk and using Recovery Catalog)


I have tested this strategy, and I have no problem recovering until the last good backup.

However, I am not able to restore the database to a specified date(i.e. last good backup is Thur, and need to restore database to Tue).

Anyone has any suggestions?
How about recovery to the previous incarnation, will this work?

Cheers
Oracbase