Best way to go for Parallel Processing?

Question

Hi all,
I am working on a ALV report, where the user will be selecting some entries and click on process button.
Currently, the entries are processed sequentially in a loop. Now, to save time on processing, the entries have to be grouped by material number, and all the groups have to be processed in parallel.
Example:
If there are 10 items, and 2 materials, the items will be grouped into 2, and two group of items will be processed in parallel, reducing the processing time by half.
I need to know, which concept to use for the parallel processing?
Call FM in Separate Task / Call FM in Background Task or is there any other way to aceive it?
What is the maximum number of parallel/background sessions supported by SAP?
I also got some code samples:
[Starting New Task|http://wiki.sdn.sap.com/wiki/display/ABAP/Parallel+Processing]
[In Background Task|http://wiki.sdn.sap.com/wiki/display/Snippets/ABAPparallelprocessingusingRFC]
Thanks,
Prabhakar.

Answer 1

Hii...
Kindly refer this code.. This will help you..
REPORT  ZRAHUL_WORKPROCESS_TASK.
TABLES : VBRK, BSEG.
SELECTION-SCREEN : BEGIN OF BLOCK B WITH FRAME TITLE TEXT-001.
PARAMETERS : S_ROW TYPE I OBLIGATORY,
             S_LINES TYPE I OBLIGATORY.
SELECTION-SCREEN : END OF BLOCK B.
TYPES : BEGIN OF ST_VBRK,
  VBELN TYPE VBRK-VBELN,
  END OF ST_VBRK.
DATA :  IT_VBRK TYPE TABLE OF ST_VBRK,
        WA_VBRK TYPE ST_VBRK.
TYPES : BEGIN OF ST_BSEG,
        BELNR TYPE BSEG-BELNR,
        VBELN TYPE BSEG-VBELN,
      END OF ST_BSEG.
DATA : IT_BSEG TYPE TABLE OF ST_BSEG,
       WA_BSEG TYPE ST_BSEG.
DATA : TEMP_BSEG TYPE TABLE OF ST_BSEG,
       TEMP_VBRK TYPE TABLE OF ST_VBRK.
DATA  : V_INDEX TYPE I VALUE 0,
        TEMP TYPE I VALUE 0,
        REMAINDER TYPE I VALUE 0,
        XXX TYPE I VALUE 0,
        T_ID(8) TYPE C.
START-OF-SELECTION.
  SELECT VBELN FROM VBRK INTO TABLE IT_VBRK UP TO S_ROW ROWS.
  IF SY-SUBRC = 0.
    SORT IT_VBRK.
  ENDIF.
  LOOP AT IT_VBRK INTO WA_VBRK.
    V_INDEX = V_INDEX + 1.
    TEMP = V_INDEX MOD S_LINES.
    IF TEMP = 0.
      APPEND WA_VBRK TO TEMP_VBRK.
      PERFORM PARALLEL_SELECT.
      CLEAR TEMP_VBRK.
    ELSE.
      APPEND WA_VBRK TO TEMP_VBRK.
    ENDIF.
  ENDLOOP.
  REMAINDER = ( S_ROW / S_LINES ).
  WAIT UNTIL XXX = REMAINDER.
  LOOP AT IT_BSEG INTO WA_BSEG.
       WRITE :/ WA_BSEG-BELNR, WA_BSEG-VBELN.
       AT LAST.
         NEW-LINE.
         WRITE :/ SY-TABIX.
       ENDAT.
  ENDLOOP.
*&      Form  PARALLEL_SELECT
*       text
*  -->  p1        text
*  <--  p2        text
FORM PARALLEL_SELECT.
  T_ID = T_ID + 1.
  CALL FUNCTION 'ZRAHUL_APPEND' STARTING NEW TASK T_ID DESTINATION IN GROUP DEFAULT PERFORMING SUBROUT ON END OF TASK
    TABLES
      IT_VBRK = TEMP_VBRK.
ENDFORM.                    " PARALLEL_SELECT
*&      Form  SUBROUTINE
*       text
*      -->P_IT_VBRK  text
*      -->P_=  text
*      -->P_TEMP_VBRK  text
*      -->P_IT_BSEG  text
*      -->P_=  text
*      -->P_TEMP_BSEG  text
FORM SUBROUT USING P_T_ID TYPE CLIKE.
  RECEIVE RESULTS FROM FUNCTION 'ZRAHUL_APPEND'
          TABLES
            IT_BSEG = TEMP_BSEG[].
  APPEND LINES OF TEMP_BSEG TO IT_BSEG.
    XXX = XXX + 1.
ENDFORM.                    " SUBROUTINE
This will be helpful.
Thanks,
Jhings