should I have only one ORACLE_HOME for all the 3 the rdbmsUse one ORACLE_HOME for your dbses. Just keep it simple.
or having ORACLE_HOME for each one of them?
Should i have only one disk group named DATA for exampleBy default ACS will create the DATA, RECO and DBFS_DG disk groups just put you datafiles in DATA and use IORM to control resource usage
or having for each database its own diskgroup?