we must upgrade our sap ecc landscape (dev, qas and prd) from Oracle 9 to Oracle 10
Dev and qas instances reside on the same server, and there is only one listener which serves both instances.
This listener is configured on the qas instance.
Now we must upgrade the instances starting from qas and leaving some days between the upgrades to be sure that everything is running fine
My question is:
Can we maintain this listener configuration when we upgrade Oracle? In other words:
If we start upgrade qas, and so the upgrade the listener process too, this listener is compatible with the other dev instance running still an Oracle 9 version?