Need to Improve pefromance for select statement using MSEG table

Question

Hi all,
We are using a select statement using MSEG table
which takes a very long time to run the program which is scheduled in back ground.
Please see the history below.;
1) Previously this program was using SELECT-ENDSELECT statement inside the loop i.e.
LOOP AT I_MCHB.
To get Material Doc. Details
      SELECT MBLNR
             MJAHR
             ZEILE INTO (MSEG-MBLNR,MSEG-MJAHR,MSEG-ZEILE)
             UP TO 1 ROWS
             FROM MSEG
            WHERE CHARG EQ I_MCHB-CHARG
             AND  MATNR EQ I_MCHB-MATNR
             AND  WERKS EQ I_MCHB-WERKS
             AND  LGORT EQ I_MCHB-LGORT.
      ENDSELECT.
Endloop.
The program was taking 1 hr  for  20 k data
2)The above statement was replaced by ALL ENTRIES to remove the SELECT-ENDSELECT from the loop.
***GET MATERIAL DOC NUMBER AND FINANCIAL YEAR DETAILS FROM MSEG TABLE
    SELECT MBLNR
           MJAHR
           ZEILE
           MATNR
           CHARG
           WERKS
           LGORT
               INTO TABLE I_MSEG
               FROM   MSEG
               FOR ALL ENTRIES IN I_MCHB
               WHERE CHARG EQ I_MCHB-CHARG
               AND   MATNR EQ I_MCHB-MATNR
               AND   WERKS EQ I_MCHB-WERKS
               AND   LGORT EQ I_MCHB-LGORT.
3)After getting the further technical analysis from BASIS team , And with the suggestion to optimize the program by changing the INDEX RANGE SCAN to
       MSEG~M.
SELECT MBLNR
           MJAHR
           ZEILE
           MATNR
           CHARG
           WERKS
           LGORT
               INTO TABLE  I_MSEG
               FROM   MSEG
               FOR ALL ENTRIES IN I_MCHB
               WHERE MATNR EQ I_MCHB-MATNR
               AND   WERKS EQ I_MCHB-WERKS
               AND   LGORT EQ I_MCHB-LGORT.
At present the program is taking 3 to 4 hrs in back ground .
The table is complete table scan using index
MSEG~M.
Please suggest to improve the performance of this
many many thanks
deepak

Answer 1

The benchmark should be the join, and I can not see how any of your solutions can be faster than the join
SELECT   .....
              INTO TABLE  ....
              UP TO 1 ROWS
              FROM mchb as a
              INNER JOIN mseg as b
              ON    amatnr EQ bmatnr
              AND  awerks  EQ bwerks
              AND  algort    EQ blgort
              And   acharg  EQ bcharg
              WHERE a~ ....
The WHERE condition must come from the select on MCHB, the field list from the total results
you want.
If you want to compare, must compare your solutions plus the select to fill I_MCHB.
Siegfried
Edited by: Siegfried Boes  on Dec 20, 2007 2:28 PM