For Oracle, don't forget to modify the SQL net configuration files (tnsnames.ora and listener.ora).
Within, SAP, do not forget to reload the profiles (RZ10), set the operation modes and instances (RZ04 and RZ03), and reconfigure the transport domain (STMS).
For more information have a look at the homogeneous and heterogeneous system copy guide. It is available for download at http://service.sap.com/instguides
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