CREATE OR REPLACE PACKAGE b_ora19_01 IS 
 
  TYPE t_tab IS TABLE OF VARCHAR2(4000); 
 
  FUNCTION foo1 RETURN t_tab 
    PIPELINED; 
 
  FUNCTION foo2 RETURN t_tab 
    PIPELINED; 
 
  FUNCTION foo3 RETURN t_tab 
    PIPELINED; 
 
END b_ora19_01; 

CREATE OR REPLACE PACKAGE BODY b_ora19_01 IS 
 
  FUNCTION foo1 RETURN t_tab 
    PIPELINED IS 
  BEGIN 
    PIPE ROW(rpad('Hello', 4000, 'x')); 
    RETURN; 
  END foo1; 
 
  FUNCTION foo2 RETURN t_tab 
    PIPELINED IS 
  BEGIN 
    FOR nn IN (SELECT t.column_value 
                 FROM TABLE(foo1) t) LOOP 
      PIPE ROW(nn.column_value); 
    END LOOP; 
    RETURN; 
  END foo2; 
 
  FUNCTION foo3 RETURN t_tab 
    PIPELINED IS 
  BEGIN 
    FOR nn IN (SELECT CAST(t.column_value AS VARCHAR2(4000)) column_value 
                 FROM TABLE(foo1) t) LOOP 
      PIPE ROW(nn.column_value); 
    END LOOP; 
    RETURN; 
  END foo3; 
 
END b_ora19_01; 

select * from table(b_ora19_01.foo2) 

select * from table(b_ora19_01.foo3)