I have a doubt:
two databases oracle (one is oracle 8i and the other is oracle 9i) can be part of a homogeneous or heterogeneous system)?
I mean that to compose a homogeneous database system, do all the nodes must be in the same version of oracle database?
Oracle8i and Oracle9i can run on the same server. I forgot what there was with the listener. I think you have to use the highest level listener. You can not run both listeners. Is that right other Oracle users?? Where is the Duck, he(or she) would know.
You could run multiple listeners, but they have to be assigned different ports. For the most part you could run either listener, but I always try to run the listener of the highest version. However I don't see what this has to do with much of what the OP asked about.
It is not clear to me what the real problem is
or how I could be sure the real question has been answered.
"Hetrogenous" is typically not used within the Oracle realm.