How can we increse this coding Part

Question

Hi there
I came across some coding to improve .while looking the progam it is unique .some say it is correct as per the Sap point of view .but some dosent.
Please verify is this the correct way for coding .
       IF NOT skont IS INITIAL.
    IF NOT aksaldo IS INITIAL.
      IF NOT summen IS INITIAL.
        LOOP AT organ.
          CLEAR: f_bwkey, f_bklas, f_bwtty, f_bwtar, sum.
          SELECT bwkey bklas bwtty bwtar SUM( salk3 ) FROM mbew
                 INTO (f_bwkey, f_bklas, f_bwtty, f_bwtar, sum)
                 WHERE bwkey EQ organ-bwkey
                 AND   matnr IN matnr
                 AND   bklas IN ibklas
                 AND   bwtar IN bwtar
                 GROUP BY bwkey bklas bwtty bwtar.
            CHECK NOT sum IS INITIAL.
            MOVE f_bwkey TO xmbew-bwkey.
            MOVE f_bklas TO xmbew-bklas.
            MOVE f_bwtty TO xmbew-bwtty.
            MOVE f_bwtar TO xmbew-bwtar.
            MOVE sum     TO xmbew-salk3.
            COLLECT xmbew.
          ENDSELECT.
          CLEAR: f_bwkey, f_bklas, f_bwtty, f_bwtar, sum.
          SELECT bwkey bklas bwtty bwtar SUM( salk3 ) FROM ebew
                 INTO (f_bwkey, f_bklas, f_bwtty, f_bwtar, sum)
                 WHERE bwkey EQ organ-bwkey
                 AND   matnr IN matnr
                 AND   bklas IN ibklas
                 AND   bwtar IN bwtar
                 GROUP BY bwkey bklas bwtty bwtar.
            CHECK NOT sum IS INITIAL.
            MOVE f_bwkey TO xmbew-bwkey.
            MOVE f_bklas TO xmbew-bklas.
            MOVE f_bwtty TO xmbew-bwtty.
            MOVE f_bwtar TO xmbew-bwtar.
            MOVE sum     TO xmbew-salk3.
            COLLECT xmbew.
          ENDSELECT.
          CLEAR: f_bwkey, f_bklas, f_bwtty, f_bwtar, sum.
          SELECT bwkey bklas bwtty bwtar SUM( salk3 ) FROM qbew
                 INTO (f_bwkey, f_bklas, f_bwtty, f_bwtar, sum)
                 WHERE bwkey EQ organ-bwkey
                 AND   matnr IN matnr
                 AND   bklas IN ibklas
                 AND   bwtar IN bwtar
                 GROUP BY bwkey bklas bwtty bwtar.
            CHECK NOT sum IS INITIAL.
            MOVE f_bwkey TO xmbew-bwkey.
            MOVE f_bklas TO xmbew-bklas.
            MOVE f_bwtty TO xmbew-bwtty.
            MOVE f_bwtar TO xmbew-bwtar.
            MOVE sum     TO xmbew-salk3.
            COLLECT xmbew.
          ENDSELECT.
        consider valuated subcontractor stocks from OBEW  "n497391
          CLEAR: f_bwkey, f_bklas, f_bwtty, f_bwtar, sum.   "n497391
          SELECT bwkey bklas bwtty bwtar SUM( salk3 )       "n497391
                 FROM obew                                  "n497391
            INTO (f_bwkey, f_bklas, f_bwtty, f_bwtar, sum)  "n497391
                 WHERE bwkey EQ organ-bwkey                 "n497391
                 AND   matnr IN matnr                       "n497391
                 AND   bklas IN ibklas                      "n497391
                 AND   bwtar IN bwtar                       "n497391
                 GROUP BY bwkey bklas bwtty bwtar.          "n497391
            CHECK NOT sum IS INITIAL.                       "n497391
            MOVE f_bwkey TO xmbew-bwkey.                    "n497391
            MOVE f_bklas TO xmbew-bklas.                    "n497391
            MOVE f_bwtty TO xmbew-bwtty.                    "n497391
            MOVE f_bwtar TO xmbew-bwtar.                    "n497391
            MOVE sum     TO xmbew-salk3.                    "n497391
            COLLECT xmbew.                                  "n497391
          ENDSELECT.                                        "n497391
        ENDLOOP.
      ELSEIF summen IS INITIAL.
        CLEAR xmbew.                                        "388498
        SELECT mandt matnr bwkey bwtar lvorm lbkum salk3
               vprsv verpr stprs peinh bklas salkv lfgja lfmon
               bwtty pstat vksal eklas qklas
               FROM mbew INTO CORRESPONDING FIELDS OF xmbew
               FOR ALL ENTRIES IN organ WHERE bwkey EQ organ-bwkey
                                        AND   matnr IN matnr
                                        AND   bklas IN ibklas
                                        AND   bwtar IN bwtar.
          APPEND xmbew.
        ENDSELECT.
Begin of Optima  APP 037
        IF NOT xmbew IS INITIAL.
      Start of Insert E_FIR.018 PRADHSA1
          SELECT matnr werks prctr
            FROM marc
            INTO TABLE i_marc
             FOR ALL ENTRIES IN xmbew
           WHERE matnr = xmbew-matnr
             AND werks = xmbew-bwkey.
      End of Insert E_FIR.018 PRADHSA1
        ENDIF.
Begin of Optima  APP 037
        CLEAR xmbew.                                        "388498
        SELECT mandt matnr bwkey bwtar lbkum salk3
               vprsv verpr stprs peinh bklas salkv lfgja lfmon
               bwtty vksal sobkz vbeln posnr
               FROM ebew INTO CORRESPONDING FIELDS OF xmbew
               FOR ALL ENTRIES IN organ WHERE bwkey EQ organ-bwkey
                                        AND   matnr IN matnr
                                        AND   bklas IN ibklas
                                        AND   bwtar IN bwtar.
          xmbew-no_sum = 'X'.
          APPEND xmbew.
        ENDSELECT.
        CLEAR xmbew.                                        "388498
        SELECT mandt matnr bwkey bwtar lbkum salk3
               vprsv verpr stprs peinh bklas salkv lfgja lfmon
               bwtty vksal sobkz pspnr
               FROM qbew INTO CORRESPONDING FIELDS OF xmbew
               FOR ALL ENTRIES IN organ WHERE bwkey EQ organ-bwkey
                                        AND   matnr IN matnr
                                        AND   bklas IN ibklas
                                        AND   bwtar IN bwtar.
          xmbew-no_sum = 'X'.
          APPEND xmbew.
        ENDSELECT.
      consider valuated subcontractor stocks from OBEW    "n497391
        CLEAR                xmbew.                         "n497391
        SELECT mandt matnr bwkey bwtar lbkum salk3          "n497391
               vprsv verpr stprs peinh bklas salkv          "n497391
               lfgja lfmon bwtty vksal sobkz lifnr          "n497391
               FROM obew INTO CORRESPONDING FIELDS OF xmbew "n497391
               FOR ALL ENTRIES IN organ                     "n497391
               WHERE  bwkey EQ organ-bwkey                  "n497391
                 AND  matnr IN matnr                        "n497391
                 AND  bklas IN ibklas                       "n497391
                 AND  bwtar IN bwtar.                       "n497391
          xmbew-no_sum = 'X'.                               "n497391
          APPEND xmbew.                                     "n497391
        ENDSELECT.                                          "n497391
      ENDIF.
Thanks in advance
Raja

Answer 1

Hi Raj,
1) Avoid select statements inside a loop which will effect the performance of your program
2) First get all the required data from tables mbew, ebew, qbew, obew, qbew, obew in to separate internal tables using for all entries from internal table organ instead of using select----endselect in a loop
3) use nested loops instead of select------endselect but use parallel cursor method in nested loop to improve performance.
The below example shows how to improve performance if we use nested loop using parallel cursor method
Nested Loop using Parallel Cursor:
REPORT  zparallel_cursor2.
TABLES:
  likp,
  lips.
DATA:
  t_likp  TYPE TABLE OF likp,
  t_lips  TYPE TABLE OF lips.
DATA:
  w_runtime1 TYPE i,
  w_runtime2 TYPE i,
  w_index LIKE sy-index.
START-OF-SELECTION.
  SELECT *
    FROM likp
    INTO TABLE t_likp.
  SELECT *
    FROM lips
    INTO TABLE t_lips.
  GET RUN TIME FIELD w_runtime1.
  SORT t_likp BY vbeln.
  SORT t_lips BY vbeln.
  LOOP AT t_likp INTO likp.
    LOOP AT t_lips INTO lips FROM w_index.
      IF likp-vbeln NE lips-vbeln.
        w_index = sy-tabix.
        EXIT.
      ENDIF.
    ENDLOOP.
  ENDLOOP.
  GET RUN TIME FIELD w_runtime2.
  w_runtime2 = w_runtime2 - w_runtime1.
  WRITE w_runtime2.
Thanks,
Naveen Kumar.