CDDX is the repository translation utility.  Use the REPOSITORY EXPORT
  and REPOSITORY IMPORT facilities of CDDX to perform a major upgrade (to
  upgrade a VAX CDD/Plus Version 4.n dictionary to an Oracle
  CDD/Repository Version 5.n or higher repository).

  Use the REPOSITORY EXPORT command to create an export file of your
  repository metadata.  After you export the repository, you delete the
  contents of the anchor, and use the REPOSITORY IMPORT command to import
  the repository metadata from the export file.

  Do not use the CDDX utility to back up, verify, or move a dictionary or
  repository; instructions for performing those operations are in the
  Oracle CDD/Repository User's Guide.