Code optimization - how can I optimize ?

Question

Basically i_mara has 19,000 records and it loops for all recors as coded.
The program is taking much time when i_mch1 has 300,000 records(approximately 40 minutes).
But in case i_mch1 had 18,000 records, it is fast.
Below is the code:
FORM output_itab4_normal .
  FIELD-SYMBOLS : <lwa_makt_maktx> TYPE tt_makt_maktx,
                  <lwa_prfrq>      TYPE tt_prfrq,
                  <lwa_mch1>       TYPE tt_mch1,
                  <lwa_mvke>       TYPE tt_mvke.
  LOOP AT i_mara INTO wa_mara.
    READ TABLE i_mch1 WITH KEY matnr = wa_mara-matnr
               ASSIGNING <lwa_mch1>.
    IF sy-subrc = 0.
*-----For Recurring Inspection, go to marc table.
      READ TABLE  i_prfrq  WITH KEY matnr = wa_mara-matnr
               ASSIGNING <lwa_prfrq>.
      IF sy-subrc = 0.
        wa_final_itab-prfrq = <lwa_prfrq>-prfrq.
        READ TABLE i_mvke WITH KEY matnr = wa_mara-matnr
                  ASSIGNING <lwa_mvke>.
        IF sy-subrc = 0.
          wa_final_itab-mvgr1 = <lwa_mvke>-mvgr1.
        ENDIF.
*-------For material description, go to makt table.
        READ TABLE i_makt_maktx  WITH KEY matnr = wa_mara-matnr
                   ASSIGNING <lwa_makt_maktx>.
        IF sy-subrc = 0.
          wa_final_itab-maktx = <lwa_makt_maktx>-maktx.
        ENDIF.
        wa_final_itab-matnr = wa_mara-matnr.
        wa_final_itab-matkl = wa_mara-matkl.
        wa_final_itab-bismt = wa_mara-bismt.
        wa_final_itab-zzbismt = wa_mara-zzbismt.
        wa_final_itab-mtart = wa_mara-mtart.
        wa_final_itab-mhdhb = wa_mara-mhdhb.
        wa_final_itab-zzshtdaysdom = wa_mara-zzshtdaysdom.
        APPEND wa_final_itab TO i_final_itab.
        CLEAR : wa_final_itab, wa_mara.
      ENDIF.          " IF sy-subrc = 0.
    ENDIF.
  ENDLOOP.
ENDFORM.                    " OUTPUT_ITAB4_NORMAL
Please help me .  Thanks in advance.

Answer 1

Hi,
You can refer to the following likns:
Code optimization
code optimization
Code Optimization
or
you can try this coding too As this avoids any looping and hence improve performance
Create another temporary internal table  ie. i_final_temp.
then do the following:
referesh i_final_temp.
append lines of i_final to i_fianl_temp.
delete i_final_temp where v_box ne 'X'
describe table i_final_temp lines v_counter.
Thank You.
Regards,
Dhanalakshmi L