You can plug existing registered databases into a CDB. You do not need to register the PDB again, as long as you perform the following steps:
Pick the wallet files from the source location and put them in the new default wallet location for the PDB.
Set the LDAP_DIRECTORY_ACCESS
parameter to the desired value in the CDB.
Similarly, when unplugging an existing PDB that is registered with the directory, you do not need to re-register the database. You need to copy the wallet to the new default location after unplug. The default location should be:
If the ORACLE_BASE
environment variable is set:
ORACLE_BASE/admin/db_unique_name/wallet
If ORACLE_BASE
is not set:
ORACLE_HOME/admin/db_unique_name/wallet