如何处理oracle并行函数中的错误

CREATE OR REPLACE FUNCTION generate_file (p_input IN SYS_REFCURSOR)
   RETURN dump_ntt  -- this just a nested table
   PIPELINED
   PARALLEL_ENABLE(PARTITION p_input BY ANY)
IS
   TYPE t_input IS RECORD
   (
     meta      VARCHAR2 (300)
   );
 
 
   TYPE tb_input IS TABLE OF t_input;
   v_input        tb_input;
   fHandle_ccif   UTL_FILE.FILE_TYPE;
   fHandle_idx    UTL_FILE.FILE_TYPE;
BEGIN
   FETCH p_input BULK COLLECT INTO v_input;
   CLOSE p_input;

   for i in 1 .. v_input.count
   loop
     fHandle_idx :=UTL_FILE.FOPEN ('HIST_LETTER_PDF', 'H' || 'filename' || '.idx', 'w');
     UTL_FILE.PUT_LINE (fHandle_idx, v_input(i).meta);
     UTL_FILE.FCLOSE (fHandle_idx);
   end loop;
   PIPE ROW (dump_ot (1));
END;
/

  SELECT *
  FROM   TABLE(
               generate_file(
                              CURSOR( 
                                     SELECT /*+ PARALLEL(s,8) */  COLUMN1
                                     FROM table1 s                                        
                                    )                                                        
                                                      )
             ) nt;