Dave, Yes. I agree. The index will be logging regardless of table logging. But if we set index to NOLOGGING, it should not log. Correct me if i am wrong.

After reading few materials, here is my understanding.

Direct load insert does not support for the below circumstances.

1. If the table has Foreign key constraint
2. If the table is clustered
3. If the table has database trigger

Thanks Dave. This site is very useful.