fast rollback from 11.2.0.4 to 11.2.0.3

Hi All !

I will upgrade database 11.2.0.3 to 11.2.0.4.

I need an rollback plan that is fast .

RMAN is not an option is too slow to rollback.

So I think to copy all datafiles to new filesystems, upgrade current database, and if needed , the rollback plan was switch filesystems .

And 11.2.0.4 and 11.2.0.4 will be diferente homes.

My problem is the size of database, 500GB, it's a production database , and copy datafiles wiil be very time consuming.

Someone have good ideas about do an upgrade from 11.2.0.3 to 11.2.0.4, with low downtime and fast rollback ?

thank you all !

Fernando