Optimization of Join statement between MKPF and MSEG table for improving pe

Question

Hi All,
I had a issue where we are executing one custom report and it is getting timed out after 45 minutes. We further executed with trace on and got to the conclusion with the help of BASIS that about 42 minutes of the 45 minutes tracetime are spent by a join over the tables  MKPF en MSEG.
This join is done by the abap statement:
  SELECT mkpf~mblnr
         mkpf~mjahr
         mkpf~bldat
         mkpf~blart
         mseg~matnr
         mseg~werks
    INTO CORRESPONDING FIELDS OF TABLE i_matdoc_we
    FROM mkpf INNER JOIN mseg ON mkpfmblnr = msegmblnr
                             AND mkpfmjahr = msegmjahr
FOR ALL entries IN i_list
   WHERE mkpf~mblnr BETWEEN lv_interval-fromnumber
                        AND lv_interval-tonumber
     AND mkpf~blart = 'WE'
     AND mkpf~bldat LE gv_last_day_fisc_period
     AND mseg~matnr = i_list-matnr
     AND mseg~werks IN s_werks.
Here, I_LIST comprises of stock for specific period as entered in the selection screen for that particular Material and plant
LV_INTERVAL is range of all goods receipts for material and gv_last_day_fisc_period is current date.
During the tracetime this statement was executed  more than 20.000 times, until the transaction timed out.
The individual executions of this select stmnt  varied (roughly) between 50 and 1200 miliseconds. (depends wheter the requested database block is in the buffercache or must be read from disk).
The acesspath used to execute the query ( see below) is optimal, given the present indexes.
Index MSEG~M is covering al the specified selection criteria for  MSEG.
Index MKPF-0 is used  to search the specified MBLNR criterium in MKPF.
The  remaining selection criteria MKPF-BLART and MKPF-BLDAT are not indexed, and imho this would also not make sense for this query.
BLART has only 3 different values n the MKPF table, and the selected value 'WE' has more than 1 million occurences.
BLDAT is selected with =<20110903, so this is not distinctive as well.
Can any one suggest some better way to write this query.
Regards,
Subhajit

Answer 1

Actually there are 2 select statements where JOIN have been introduced and especially the time out is occurring in the second JOIN.
Find all goods receipts for material
  PERFORM get_number_range_matdoc USING '03'
                               CHANGING lv_interval.
  SELECT mkpf~mblnr
         mkpf~mjahr
         mkpf~bldat
         mkpf~blart
         mseg~matnr
         mseg~werks
    INTO CORRESPONDING FIELDS OF TABLE i_matdoc_we
    FROM mkpf INNER JOIN mseg ON mkpfmblnr = msegmblnr
                             AND mkpfmjahr = msegmjahr
FOR ALL entries IN i_list
   WHERE mkpf~mblnr BETWEEN lv_interval-fromnumber
                        AND lv_interval-tonumber
     AND mkpf~blart = 'WE'
     AND mkpf~bldat LE gv_last_day_fisc_period
AND mseg~matnr = i_list-matnr
    AND mseg~werks IN s_werks.
  CLEAR lv_interval.
  PERFORM get_number_range_matdoc USING '02'
                               CHANGING lv_interval.
Find all goods issues for material
  SELECT mkpf~mblnr
         mkpf~mjahr
         mkpf~bldat
         mkpf~blart
         mseg~matnr
         mseg~werks
    INTO CORRESPONDING FIELDS OF TABLE i_matdoc_wa
    FROM mkpf INNER JOIN mseg ON mkpfmblnr = msegmblnr
                             AND mkpfmjahr = msegmjahr
FOR ALL entries IN i_list
   WHERE mkpf~mblnr BETWEEN lv_interval-fromnumber
                        AND lv_interval-tonumber
     AND ( mkpfblart = 'WA' OR mkpfblart = 'WI' )
     AND mkpf~bldat LE gv_last_day_fisc_period
AND mseg~matnr = i_list-matnr
     AND mseg~bwart NE '561'
     AND mseg~bwart NE '562'
     AND mseg~bwart NE '961'
AND mseg~bwart NE '962'
AND mseg~werks IN s_werks.
Mainly the second JOIN is creating the problem... In the backend ORACLE is being used as database.
Please suggest how I can improve the performance of these joins as its taking more than 45 mins..