What is the meaning of "select * from relational(owner.table)"?
It appears to be inert. I tested this on XE 11 and found that it does nothing.

CREATE TABLE dbausers AS SELECT * FROM dba_users;

-- Function doesn't affect result set.
SELECT * FROM dbausers
MINUS
SELECT * FROM RELATIONAL(dbausers);

SELECT * FROM RELATIONAL(dbausers)
MINUS
SELECT * FROM dbausers;