We used to take cold backup of our 310GB database on sundays with 4 channels. It takes around 2~3 hours. We used IBM-Tivoli tape library. Our file system was RAW.

But, my dream yet possible strategy would be something like..

1. Move all your read only segments to a read only tablespace and free the headers of these tablespaces by making them read only. Take one time back up of these. by doing this, we can minimize the size of actual database to be taken backup regularly.

2. Organize the tablespaces into 5 or 6 groups. You can take back up of these groups at one per day. That is, you are taking a set of tablespaces one day and other set next day and so on. Obviously, the database should be in archive log mode and all of these backups are hot backups.

By following this strategy, we can make optimal use of available resources.

No no, the strategy mentioned above is not my idea.. Happened to read Andrew Symkovsky's reply in some other forum.