non-equi full outer join is not supported

  Explanation:  An attempt was made to specify a full  outer  join
  without  using  an  equijoin  condition  in the ON clause of the
  joined table expression.  Full outer joins that do  not  include
  an  equijoin  condition are not supported in the current version
  of Oracle Rdb.

  User Action:  Specify a  full  outer  join  with  at  least  one
  equijoin  condition,  or  rephrase  the query by using the UNION
  operator to get the intended full outer join result.