And one thing more...

What my thinking is that when the database rolls forward the redo is actually rebuilding the rollback segments...

Think of it this way, when a DML occurs on a table the undo goes to the rollback, what happens to the changes that are made in the rollback, well they go in the redo...

So during a rollforwad the rollback segments are built up and then the database finds from these rollback segments what is uncommitted and the rolls back.

Correct me if i'm wrong