SANDBOX@ee>;select 1 from dual a, dual b where a.dummy (+) = b.dummy (+);
select 1 from dual a, dual b where a.dummy (+) = b.dummy (+)
                                               *
ERROR at line 1:
ORA-01468: a predicate may reference only one outer-joined table

SANDBOX@ee>;select 1 from dual a full join dual b on a.dummy = b.dummy;
         1
----------
         1

SELECT * FROM employees e, (SELECT * FROM departments d
                            WHERE e.department_id = d.department_id);

ORA-00904: "E"."DEPARTMENT_ID": invalid identifier

SELECT * FROM employees e, LATERAL(SELECT * FROM departments d
                                   WHERE e.department_id = d.department_id);