Niall, I think it will be interesting migration strategy. Even I will be waiting for someone to confirm if they have done or can be done. But I think as dataguard also allows you to setup standby with different word size , setting up dataguard is a better option. Cheers Amit On Thu, Mar 11, 2010 at 4:28 PM, Niall Litchfield < niall.litchfield@xxxxxxxxx> wrote: > Does anyone know if a 64 bit db will sit happily on an existing 32 bit > cluster? If so and I can't in principle see why not then it would make a > nice migration path here >