topic Re: Binary search problem in Application Development and Automation Discussions

Binary search problem

former_member925838 — Fri, 28 Dec 2012 07:39:25 GMT

Dear Experts,

I am having trouble in reading internal table through binary search.

This is my code :

Case Ist:

      SORT it_mseg by mblnr mjahr.
       SORT it_mkpf by mblnr mjahr.



       LOOP at it_mseg INTO wa_mseg.
         id1 = sy-tabix.
         READ TABLE it_mkpf INTO wa_mkpf with KEY mblnr = wa_mseg-mblnr mjahr = wa_mseg-mjahr BINARY SEARCH.
         if sy-subrc = 0.
           wa_mseg-budat = wa_mkpf-budat.
           wa_mseg-bldat = wa_mkpf-bldat.
           MODIFY it_mseg FROM wa_mseg INDEX id1.
         ENDIF.
       ENDLOOP.

In above case binary search is working fine.

Case 2nd :

sort it_mseg by matnr DESCENDING.
   it_mseg2[] = it_mseg[].
   SORT it_mseg2 STABLE by matnr DESCENDING budat DESCENDING.

   LOOP at it_final INTO wa_final.
     CLEAR rpu.
     rpu = wa_final-rpu.
     READ TABLE it_mseg INTO wa_mseg with KEY matnr = wa_final-matnr BINARY SEARCH. " In this case only the material with index 1 is read in     all other cases sy-subrc become 4.

i am not getting why it is doing this as in 1st case it is executing properly.

    if sy-subrc = 0.
     LOOP at it_mseg2 INTO wa_mseg2 FROM sy-tabix.
     if wa_final-MBWBEST gt 0.
     MOVE-CORRESPONDING wa_final to wa_final3.
     if wa_final-MBWBEST ge wa_mseg2-menge.
       wa_final3-mblnr = wa_mseg2-mblnr.
       wa_final3-budat = wa_mseg2-budat.
       wa_final3-MBWBEST = wa_mseg2-menge.

       wa_final-MBWBEST = wa_final-MBWBEST - wa_final3-MBWBEST.

        IF wa_final3-budat IS NOT INITIAL.
       wa_final3-cnt = s_date - wa_final3-budat. "LETZTABG.
       ENDIF.

       wa_final3-rpu = rpu * wa_final3-MBWBEST.
       APPEND wa_final3 to it_final3.

     ELSe. "wa_final-MBWBEST lt wa_mseg2-menge_i.
       wa_final3-mblnr = wa_mseg2-mblnr.
       wa_final3-budat = wa_mseg2-budat.
       wa_final3-MBWBEST = wa_final-MBWBEST.

        IF wa_final3-budat IS NOT INITIAL.
       wa_final3-cnt = s_date - wa_final3-budat. "LETZTABG.
       ENDIF.
        wa_final3-rpu = rpu * wa_final3-MBWBEST.
       APPEND wa_final3 to it_final3.
       wa_final-MBWBEST = 0.
     ENdif.

   ENDIF.
   at END OF matnr.
     exit.
   ENDAT.
     ENDLOOP.
   ENDIF.
   ENDLOOP.

Please help

Thanks,

Amar

Re: Binary search problem

Former Member — Fri, 28 Dec 2012 08:09:36 GMT

Hi Amar,

In Case # 1 : You use

SORT it_mseg by mblnr mjahr.

SORT it_mkpf by mblnr mjahr.

" without using ASCENDING / DESCENDING option

so SAP by default SORT in ASCENDING then ur

BINARY SEARCH WORKING F9 .

READ TABLE it_mkpf INTO wa_mkpf with KEY mblnr = wa_mseg-mblnr

mjahr =wa_mseg-mjahr BINARY SEARCH.

In Case # 2 :

sort it_mseg by matnr DESCENDING

" Using Sort in Descending order this is a main reason ur

BINARY SEARCH Not Working .

READ TABLE it_mseg INTO wa_mseg with KEY matnr = wa_final-matnr BINARY SEARCH.

Please check

standard tables are subject to a linear search. If the addition BINARY SEARCH is specified, the search is binary instead of linear. This considerably reduces the runtime of the search for larger tables (from approximately 100 entries upwards). For the binary search, the table must be sorted by the specified search key in ascending order. Otherwise the search will not find the correct row.
sorted tables are subject to a binary search if the specified search key is or includes a starting field of the table key. Otherwise it is linear. If the specified search key is or inclucdes an starting field of the table key, the addition BINARY SEARCH can be specified for sorted tables, but has no effect.
For hashed tables, the hash algorithm is used if the specified search key includes the table key. Otherwise the search is linear. The addition BINARY SEARCH is not permitted for hashed tables.

Regard's

Smruti

Re: Binary search problem

former_member925838 — Fri, 28 Dec 2012 08:19:48 GMT

Thanks Smruti,

it was very silly mistake.

thanks for the help.

Amar

Re: Binary search problem

sudipDas — Fri, 28 Dec 2012 09:35:27 GMT

Do not put DESCENDING key word in sorting it_mseg.

Regards

Sudip