This page will show you all the Available reports for Metamodel/Metamodel Usage, once you select a report name, it will open the report query page. copy and paste it to your PC and run it from, toad or any other DB tools you have.
| Element statistics
|| Provides the total number of elements for each class in the specified repository instance.
| Unused Classes by Repository Type
|| Lists all classes that are not used by the metadata elements in the repositories of the specified repository type.