SELECT p1.name, p1.value val_inst1, p2.value val_inst2
FROM gv$parameter p1
JOIN gv$parameter p2 ON p1.name = p2.name
WHERE p1.inst_id = 1
AND p2.inst_id = 2
AND p1.value != p2.value
AND p1.name NOT IN ('instance_number', 'instance_name', 
'local_listener','thread','undo_tablespace','core_dump_dest')