create or replace procedure refcur1(refcur_out out sys_refcursor) 
is 
begin 
  open refcur_out for q'#select 'A' alphabet from dual 
  union all 
  select 'B' from dual 
  union all 
  select 'C' from dual 
  #'; 
end; 

create or replace procedure refcur2(refcur_out out sys_refcursor) 
is 
begin 
  open refcur_out for q'#select 'A' alphabet from dual 
  union all 
  select 'B' from dual 
  union all 
  select 'C' from dual 
  #'; 
end; 

create or replace type rc_tt is table of varchar2(1) 

create or replace function tf1 return rc_tt 
is 
  l sys_refcursor; 
  l_returnvalue rc_tt; 
begin 
  refcur1(l); 
  fetch l bulk collect into l_returnvalue; 
  RETURN l_returnvalue; 
end; 

select * from table(tf1) 

create or replace function tf2 return rc_tt 
is 
  l sys_refcursor; 
  l_returnvalue rc_tt; 
begin 
  refcur2(l); 
  fetch l bulk collect into l_returnvalue; 
  RETURN l_returnvalue; 
end; 

select * from table(tf2) 

select * from table(tf1) 
minus 
select * from table(tf2)