CREATE OR REPLACE FUNCTION public.test_insert(i_id integer)
 RETURNS integer
 LANGUAGE plpgsql
AS $function$
DECLARE
begin
	
  insert into tts.test_ora_db(id) values(i_id); 	
  
  return i_id; 
  
EXCEPTION
  WHEN others THEN
    RAISE WARNING 'err.create_user_account.Others State: %  Errm: %', sqlstate, sqlerrm;
    return sqlerrm;
END;
$function$

CREATE OR REPLACE FUNCTION Call_Postgre_n(v_Func VARCHAR2) RETURN NUMBER IS
  v_Cursor BINARY_INTEGER;
  v_Nr     BINARY_INTEGER;
  v_Ret    NUMBER;
BEGIN
  v_Cursor := Dbms_Hs_Passthrough.Open_Cursor@Pgsql;

  Dbms_Hs_Passthrough.Parse@Pgsql(v_Cursor,
                                  'select ' || v_Func);
  v_Nr := Dbms_Hs_Passthrough.Fetch_Row@Pgsql(v_Cursor);
  Dbms_Hs_Passthrough.Get_Value@Pgsql(v_Cursor,
                                      1,
                                      v_Ret);
  Dbms_Hs_Passthrough.Close_Cursor@Pgsql(v_Cursor);
  RETURN v_Ret;
END;

select Call_Postgre_n('public.test_insert(10)') as rez from dual

   select * from tts.test_ora_db;

postgres=# select test_insert(10);
 test_insert
-------------
          10
(1 row)

postgres=# select * from dropme;
 x
----
 10
(1 row)

-- на oracle
SQL> select dbms_hs_passthrough.execute_immediate@vvpsql('select test_insert(10)') from dual;

DBMS_HS_PASSTHROUGH.EXECUTE_IMMEDIATE@VVPSQL('SELECTTEST_INSERT(10)')
---------------------------------------------------------------------
                                                                    1

SQL> select * from "dropme"@VVPSQL;

         x
----------
        10
        10

SQL>  select dbms_hs_passthrough.execute_immediate@vvpsql('select test_insert(10)') from dual;

DBMS_HS_PASSTHROUGH.EXECUTE_IMMEDIATE@VVPSQL('SELECTTEST_INSERT(10)')
---------------------------------------------------------------------
                                                                    1

SQL> select * from "dropme"@VVPSQL;

         x
----------
        10
        10
        10
-- на postgres
postgres=# select * from dropme;
 x
----
 10

-- на oracle
SQL> commit;

Commit complete.

SQL> select * from "dropme"@VVPSQL;

         x
----------
        10
        10
        10

-- на postgres
postgres=# select * from dropme;
 x
----
 10
 10
 10
(3 rows)