Redaction on view with UNION causes ORA-28094: SQL construct not supported by data redaction

Redaction of 9 digit SSNs.',

   column_description     => 'pi_ssn contains SSNs for the member.');

END;

/

Query view:

SQL> select * from redaction_schema.all_test;

select * from redaction_schema.all_test

                               *

ERROR at line 1:

ORA-28094: SQL construct not supported by data redaction

Query using inline union fails too:

SQL> select * from (

  2       select * from redaction_schema.test_red

  3       union

  4       select * from redaction_schema.test_nored

  5                );

     select * from redaction_schema.test_nored

                                    *

ERROR at line 4:

ORA-28094: SQL construct not supported by data redaction