It would be very useful if the Sessions featue used the gv$ views instead of the v$ views. This, plus the addition of the INST_ID column value on the screens would show sessions for all instances in a RAC database. It would still work for single-instance databases, so no functionality would be lost and no need to try and manage two sets of queries. If you are unfamiliar with those views, the only thing to know is that whenever you join two of them together you need to include INST_ID in the join condition. Other than that, they are just like the V$ views.