Regadrding select statements

Question

Hello to all
Here in my requirement i did one select query logic
bt performance wise it is not working proper way
if u find any changes relevant to below select statement plz reply me
here is my Select Query
Extract all the data from the database tables .
Retrieving data from table MARA .
  SELECT *  FROM mara
             INTO CORRESPONDING FIELDS OF TABLE  it_mara
            WHERE matnr IN s_matnr  AND  mtart IN s_mtart AND ernam IN s_ernam.
            sort it_mara by matnr.
DELETE ADJACENT DUPLICATES FROM it_mara comparing all fields.
IF sy-subrc NE 0.
    MESSAGE s005(zmm).
    REFRESH: it_marc.
    STOP.
  ENDIF.
Retrieving data of Product Group Level3 on the condition that ZZPARENT should not be empty  .
  IF  wa_mara-zzparent NE  ' '.
    READ TABLE it_mara INTO wa_mara WITH KEY matnr = wa_mara-matnr.
    MOVE wa_mara-zzparent TO wa_final-prodh3.
  ENDIF.
  SELECT   matnr werks mtvfp mfrgr ladgr prctr sernp stawn ekgrp dismm lgfsb insmk
               FROM  marc
               INTO  CORRESPONDING  FIELDS OF TABLE  it_marc
               FOR ALL ENTRIES IN it_mara
              WHERE    matnr = it_mara-matnr
               AND     werks IN s_werks .
       sort it_marc by matnr werks.
DELETE ADJACENT DUPLICATES FROM it_marc.
  IF sy-subrc NE 0.
    MESSAGE s005(zmm).
    REFRESH: it_marc.
    STOP.
  ENDIF.
Retrieving data from table MVKE .
  SELECT  matnr vkorg vtweg dwerk kondm ktgrm mtpos mvgr1 mvgr2 mvgr3 mvgr4 mvgr5
            FROM mvke
            INTO CORRESPONDING FIELDS OF  TABLE it_mvke
            FOR ALL ENTRIES IN IT_MARA
            where matnr = it_mara-matnr and
                  vkorg IN s_vkorg.
  IF sy-subrc NE 0.
    MESSAGE s005(zmm).
    REFRESH: it_marc.
    STOP.
  ENDIF.
Retrieving data from table MARM, satisfying the condition for Case Pack Factor as CS .
  SELECT  MATNR  meinh umrez laeng breit hoehe meabm volum voleh brgew
           FROM marm
           INTO CORRESPONDING FIELDS OF TABLE it_marm
           FOR ALL ENTRIES IN IT_MARA
          WHERE MATNR =  IT_MARA-MATNR
          AND meinh = 'CS'.
Retrieving data from table MAKT .
  SELECT   matnr maktx
            FROM makt
            INTO CORRESPONDING  FIELDS OF  TABLE it_makt
           WHERE matnr IN  s_matnr .
Retrieving data from table AMPL and fetching data for field GPCCODE  .
SELECT   bmatn ematn
          FROM     ampl
          INTO  CORRESPONDING FIELDS OF TABLE it_ampl
          FOR ALL ENTRIES IN it_mara
         WHERE    bmatn = it_mara-matnr
          AND     datuv LE sy-datum
          AND     datub GE sy-datum.
IF NOT wa_ampl IS INITIAL.
   READ TABLE it_ampl INTO wa_ampl WITH KEY bmatn = wa_mara-matnr.
   MOVE wa_ampl-ematn  TO wa_final-gpccode.
ELSE.
   SELECT bmatn ematn
          FROM ampl
          INTO CORRESPONDING FIELDS OF TABLE it_ampl
          FOR ALL ENTRIES IN it_mara
         WHERE  bmatn = it_mara-matnr.
   IF NOT wa_ampl IS INITIAL.
     READ TABLE it_ampl INTO wa_ampl WITH KEY bmatn = wa_ampl-bmatn.
     MOVE wa_mara-mfrpn TO  wa_final-gpccode.
   ELSE.
     wa_final-gpccode = ' '.
   ENDIF.
ENDIF.
Moving Relevant  data  to IT_FINAL (Final Internal Table )  .
  LOOP AT it_mara INTO wa_mara .
    MOVE-CORRESPONDING wa_mara TO wa_final.
    MOVE :  wa_mara-zzparent TO wa_final-prodh3.
    READ TABLE it_mvke  INTO wa_MVKE  with key vkorg = wa_mvke-vkorg.
    MOVE :   wa_mvke-vkorg  TO  wa_final-vkorg,
             wa_mvke-vtweg  TO  wa_final-vtweg,
             wa_mvke-dwerk  TO  wa_final-dwerk,
             wa_mvke-kondm  TO  wa_final-kondm,
             wa_mvke-ktgrm  TO  wa_final-ktgrm,
             wa_mvke-mtpos  TO  wa_final-mtpos,
             wa_mvke-mvgr1  TO  wa_final-mvgr1,
             wa_mvke-mvgr2  TO  wa_final-mvgr2,
             wa_mvke-mvgr3  TO  wa_final-mvgr3,
             wa_mvke-mvgr4  TO  wa_final-mvgr4,
             wa_mvke-mvgr5  TO  wa_final-mvgr5.
   READ TABLE  it_marc     INTO wa_marc WITH KEY   matnr = wa_marc-matnr .
   MOVE :   wa_marc-mtvfp  TO  wa_final-mtvfp,
            wa_marc-mfrgr  TO  wa_final-mfrgr,
            wa_marc-ladgr  TO  wa_final-ladgr,
            wa_marc-prctr  TO  wa_final-prctr,
            wa_marc-sernp  TO  wa_final-sernp,
            wa_marc-stawn  TO  wa_final-stawn,
            wa_marc-ekgrp  TO  wa_final-ekgrp,
            wa_marc-dismm  TO  wa_final-dismm,
            wa_marc-lgfsb  TO  wa_final-lgfsb,
            wa_marc-insmk  TO  wa_final-insmk.
    READ TABLE it_ampl     INTO wa_ampl WITH KEY bmatn = wa_mara-matnr BINARY SEARCH.
    MOVE :   wa_ampl-bmatn  TO  wa_final-bmatn.
    READ TABLE it_marm     INTO wa_marm WITH KEY matnr =  wa_mara-matnr BINARY SEARCH.
    MOVE:    wa_marm-meinh TO   wa_final-meinh,
             wa_marm-umrez TO   wa_final-umrez,
             wa_marm-laeng TO   wa_final-laeng,
             wa_marm-breit TO   wa_final-breit,
             wa_marm-hoehe TO   wa_final-hoehe,
             wa_marm-meabm TO   wa_final-meabm,
             wa_marm-volum TO   wa_final-volum,
             wa_marm-brgew TO   wa_final-brgew.
    READ  TABLE it_makt    INTO wa_makt WITH KEY matnr = wa_mara-matnr.
    MOVE     wa_makt-maktx TO   wa_final-maktx.
*******************************FOR SALE ORGANIZATION CHECK BOX***************
    IF  c_sodata = 'X'.
      SELECT   matnr vkorg lvorm
               FROM  mvke
               INTO  CORRESPONDING FIELDS OF TABLE   it_checkselected
               FOR ALL ENTRIES IN it_mara
              WHERE  matnr   = it_mara-matnr
               AND   vkorg  IN s_vkorg
               AND   vkorg NE 'YMUS'
               AND   lvorm EQ ' '.
      IF sy-subrc NE 0.
        MESSAGE s005(zmm).
        STOP.
      ENDIF.
      LOOP AT it_checkselected INTO wa_checkselected.
        READ  TABLE  it_checkselected INDEX sy-index INTO wa_checkselected  .
        MOVE : wa_checkselected-vkorg TO wa_final-vkorg,
               wa_checkselected-lvorm TO wa_final-lvorm.
      ENDLOOP.
    ENDIF.
***************************FOR PLANT CHECK BOX*****************************
Retrieving data if check box  for Plantdata is Enabled .
    IF  c_pdata = 'X'.
     SELECT   matnr werks mtvfp mfrgr ladgr prctr sernp stawn ekgrp dismm lgfsb insmk
              FROM  marc
              INTO  CORRESPONDING  FIELDS OF TABLE  it_marc
              FOR ALL ENTRIES IN it_mara
             WHERE    matnr = it_mara-matnr
              AND     werks IN s_werks .
      READ TABLE  it_marc     INTO wa_marc WITH KEY   matnr = wa_marc-matnr  BINARY SEARCH.
      MOVE : wa_marc-werks  TO  wa_final-werks,
             wa_marc-mtvfp  TO  wa_final-mtvfp,
             wa_marc-mfrgr  TO  wa_final-mfrgr,
             wa_marc-ladgr  TO  wa_final-ladgr,
             wa_marc-prctr  TO  wa_final-prctr,
             wa_marc-sernp  TO  wa_final-sernp,
             wa_marc-stawn  TO  wa_final-stawn,
             wa_marc-ekgrp  TO  wa_final-ekgrp,
             wa_marc-dismm  TO  wa_final-dismm,
             wa_marc-lgfsb  TO  wa_final-lgfsb,
             wa_marc-insmk  TO  wa_final-insmk.
      SELECT   werks lgnum
               FROM  t320
               INTO CORRESPONDING  FIELDS OF TABLE  it_t320
               FOR  ALL ENTRIES IN it_marc
              WHERE werks = it_marc-werks
                AND werks  IN s_werks.
      SELECT  matnr lgnum ltkza ltkze lgbkz block lhmg1 lhme1 lety1 zzcase_orient
              FROM mlgn
              INTO  CORRESPONDING FIELDS OF TABLE it_mlgn
              FOR ALL ENTRIES IN it_t320
             WHERE lgnum = it_t320-lgnum
              AND  matnr IN s_matnr.
      READ TABLE it_mlgn      INTO wa_mlgn WITH KEY lgnum = wa_t320-lgnum   BINARY SEARCH.
      MOVE:     wa_mlgn-lgnum TO wa_final-lgnum,
                wa_mlgn-ltkza TO wa_final-ltkza,
                wa_mlgn-ltkze TO wa_final-ltkze,
                wa_mlgn-lgbkz TO wa_final-lgbkz,
                wa_mlgn-block TO wa_final-block,
                wa_mlgn-lhmg1 TO wa_final-lhmg1,
                wa_mlgn-lhme1 TO wa_final-lhme1,
                wa_mlgn-lety1 TO wa_final-lety1,
                wa_mlgn-zzcase_orient TO wa_final-zzcase_orient.
      SELECT   matnr bklas
               FROM mbew
              INTO TABLE it_mbew
              FOR ALL ENTRIES IN it_mara
             WHERE matnr  = it_mara-matnr.
      READ TABLE  it_mbew    INTO wa_mbew WITH KEY matnr = wa_mara-matnr  BINARY SEARCH.
      MOVE     wa_mbew-bklas TO   wa_final-bklas.
    ENDIF.
    APPEND wa_final TO it_final .
  ENDLOOP.
DELETE ADJACENT DUPLICATES FROM it_final comparing all fields.
  IF sy-subrc NE 0.
    MESSAGE  s005(zmm).
    STOP.
    CLEAR sy-subrc.
  ENDIF.
  REFRESH: it_mara,it_marc,it_mvke,it_mlgn,it_ampl,it_t320,
           it_checkselected.
plese help me its an urgent requirement
Points will be rewarded fro satisfying answer
Regards
ASLAM

Answer 1

select only those fields which u want in ur program, in the first select statement u are selecting all fields, u can avoiid that.
secondly u are using into corresponding fields of table, try to avoid that also
define the IT with fields which u r retrieving from the select statement and use into table, its more efficient that into corresponding fields
try to avoid select inside loop statement.
bye