Hello Experts please give some suggestions in this...

Former Member · ‎12-04-2007

Hello Experts . Please give suggestions in changing the below code to increase the performance . Thanks in advance for all your suggestions...

PARAMETERS : Pr_WERKS LIKE EKPO-WERKS OBLIGATORY,

Pr_EINDT LIKE EKET-EINDT OBLIGATORY.

SELECT-OPTIONS : S_LIFNR FOR EKKO-LIFNR MATCHCODE

OBJECT KRED OBLIGATORY.

DATA: BEGIN OF SELEC OCCURS 10,

SIGN(1),

OPTION(2),

LOW LIKE p_eindt,

HIGH LIKE p_eindt,

END OF SELEC.

SELEC-SIGN = 'I'.

SELEC-OPTION = 'BT'.

SELEC-LOW = pr_eindt.

SELEC-HIGH = pr_eindt + 31.

SELECT * FROM EKET WHERE EINDT IN SELEC.

CHECK EKET-MENGE NE 0.

SELECT * FROM EKPO WHERE EBELN = EKET-EBELN AND

EBELP = EKET-EBELP AND

WERKS = Pr_WERKS.

SELECT * FROM EKKO WHERE EBELN = EKET-EBELN AND

LIFNR IN S_LIFNR AND

BSTYP = 'L' AND

FRGKE = 'R'.

SELECT SINGLE * FROM MAKT WHERE MATNR = EKPO-MATNR AND

SPRAS = 'EN'.

SELECT SINGLE * FROM LFA1 WHERE LIFNR = EKKO-LIFNR.

EXTRACT DETAIL.

ENDSELECT.

former_member194613 · ‎12-04-2007

It is not necessary to have triple nested selects. With the INTO clauses it should be possible, to improve it even more either with FOR ALL ENTRIES or JOINs.


SELECT * FROM EKET 
             WHERE EINDT IN SELEC.
             AND       MENGE NE '0'.

   SELECT * FROM EKPO
                 WHERE EBELN = EKET-EBELN
                 AND       EBELP = EKET-EBELP 
                 AND     WERKS = Pr_WERKS.

      SELECT SINGLE * FROM MAKT
                    WHERE MATNR = EKPO-MATNR
                    AND      SPRAS = 'EN'.
    ENDSELECT.


    SELECT * FROM EKKO 
                 WHERE EBELN = EKET-EBELN
                 AND      LIFNR IN S_LIFNR 
                 AND      BSTYP = 'L' 
                 AND      FRGKE = 'R'.


         SELECT SINGLE * FROM LFA1 
                       WHERE LIFNR = EKKO-LIFNR.
     ENDSELECT.

EXTRACT DETAIL.

ENDSELECT.

Siegfried

Former Member · ‎12-04-2007

1.Avoid SELECT … END SELECT

2.Avoid SELECT * , fetch required fields only.

3.Write FOR ALL ENTRIES option for next select statements.

4. Before writing FOR ALL ENTRIES , check that internal table is initial or not.

if it helps plz give some good points

Thanks

Siva Kumar

Former Member · ‎12-04-2007

Ways of Performance Tuning

1. Selection Criteria

2. Select Statements

• Select Queries

• SQL Interface

• Aggregate Functions

• For all Entries

Select Over more than one internal table

Selection Criteria

1. Restrict the data to the selection criteria itself, rather than filtering it out using the ABAP code using CHECK statement.

2. Select with selection list.

SELECT * FROM SBOOK INTO SBOOK_WA.

CHECK: SBOOK_WA-CARRID = 'LH' AND

SBOOK_WA-CONNID = '0400'.

ENDSELECT.

The above code can be much more optimized by the code written below which avoids CHECK, selects with selection list

SELECT CARRID CONNID FLDATE BOOKID FROM SBOOK INTO TABLE T_SBOOK

WHERE SBOOK_WA-CARRID = 'LH' AND

SBOOK_WA-CONNID = '0400'.

Select Statements Select Queries

1. Avoid nested selects

SELECT * FROM EKKO INTO EKKO_WA.

SELECT * FROM EKAN INTO EKAN_WA

WHERE EBELN = EKKO_WA-EBELN.

ENDSELECT.

The above code can be much more optimized by the code written below.

SELECT P_{F1 P}F2 F_{F3 F}F4 INTO TABLE ITAB

FROM EKKO AS P INNER JOIN EKAN AS F

ON P_{EBELN = F}EBELN.

Note: A simple SELECT loop is a single database access whose result is passed to the ABAP program line by line. Nested SELECT loops mean that the number of accesses in the inner loop is multiplied by the number of accesses in the outer loop. One should therefore use nested SELECT loops only if the selection in the outer loop contains very few lines or the outer loop is a SELECT SINGLE statement.

2. Select all the records in a single shot using into table clause of select statement rather than to use Append statements.

SELECT * FROM SBOOK INTO SBOOK_WA.

CHECK: SBOOK_WA-CARRID = 'LH' AND

SBOOK_WA-CONNID = '0400'.

ENDSELECT.

The above code can be much more optimized by the code written below which avoids CHECK, selects with selection list and puts the data in one shot using into table

SELECT CARRID CONNID FLDATE BOOKID FROM SBOOK INTO TABLE T_SBOOK

WHERE SBOOK_WA-CARRID = 'LH' AND

SBOOK_WA-CONNID = '0400'.

3. When a base table has multiple indices, the where clause should be in the order of the index, either a primary or a secondary index.

To choose an index, the optimizer checks the field names specified in the where clause and then uses an index that has the same order of the fields. In certain scenarios, it is advisable to check whether a new index can speed up the performance of a program. This will come handy in programs that access data from the finance tables.

4. For testing existence, use Select.. Up to 1 rows statement instead of a Select-Endselect-loop with an Exit.

SELECT * FROM SBOOK INTO SBOOK_WA

UP TO 1 ROWS

WHERE CARRID = 'LH'.

ENDSELECT.

The above code is more optimized as compared to the code mentioned below for testing existence of a record.

SELECT * FROM SBOOK INTO SBOOK_WA

WHERE CARRID = 'LH'.

EXIT.

ENDSELECT.

5. Use Select Single if all primary key fields are supplied in the Where condition .

If all primary key fields are supplied in the Where conditions you can even use Select Single.

Select Single requires one communication with the database system, whereas Select-Endselect needs two.

Select Statements SQL Interface

1. Use column updates instead of single-row updates

to update your database tables.

SELECT * FROM SFLIGHT INTO SFLIGHT_WA.

SFLIGHT_WA-SEATSOCC =

SFLIGHT_WA-SEATSOCC - 1.

UPDATE SFLIGHT FROM SFLIGHT_WA.

ENDSELECT.

The above mentioned code can be more optimized by using the following code

UPDATE SFLIGHT

SET SEATSOCC = SEATSOCC - 1.

2. For all frequently used Select statements, try to use an index.

SELECT * FROM SBOOK CLIENT SPECIFIED INTO SBOOK_WA

WHERE CARRID = 'LH'

AND CONNID = '0400'.

ENDSELECT.

The above mentioned code can be more optimized by using the following code

SELECT * FROM SBOOK CLIENT SPECIFIED INTO SBOOK_WA

WHERE MANDT IN ( SELECT MANDT FROM T000 )

AND CARRID = 'LH'

AND CONNID = '0400'.

ENDSELECT.

3. Using buffered tables improves the performance considerably.

Bypassing the buffer increases the network considerably

SELECT SINGLE * FROM T100 INTO T100_WA

BYPASSING BUFFER

WHERE SPRSL = 'D'

AND ARBGB = '00'

AND MSGNR = '999'.

The above mentioned code can be more optimized by using the following code

SELECT SINGLE * FROM T100 INTO T100_WA

WHERE SPRSL = 'D'

AND ARBGB = '00'

AND MSGNR = '999'.

Select Statements Aggregate Functions

• If you want to find the maximum, minimum, sum and average value or the count of a database column, use a select list with aggregate functions instead of computing the aggregates yourself.

Some of the Aggregate functions allowed in SAP are MAX, MIN, AVG, SUM, COUNT, COUNT( * )

Consider the following extract.

Maxno = 0.

Select * from zflight where airln = ‘LF’ and cntry = ‘IN’.

Check zflight-fligh > maxno.

Maxno = zflight-fligh.

Endselect.

The above mentioned code can be much more optimized by using the following code.

Select max( fligh ) from zflight into maxno where airln = ‘LF’ and cntry = ‘IN’.

Select Statements For All Entries

• The for all entries creates a where clause, where all the entries in the driver table are combined with OR. If the number of entries in the driver table is larger than rsdb/max_blocking_factor, several similar SQL statements are executed to limit the length of the WHERE clause.

The plus

• Large amount of data

• Mixing processing and reading of data

• Fast internal reprocessing of data

• Fast

The Minus

• Difficult to program/understand

• Memory could be critical (use FREE or PACKAGE size)

Points to be must considered FOR ALL ENTRIES

• Check that data is present in the driver table

• Sorting the driver table

• Removing duplicates from the driver table

Consider the following piece of extract

Loop at int_cntry.

Select single * from zfligh into int_fligh

where cntry = int_cntry-cntry.

Append int_fligh.

Endloop.

The above mentioned can be more optimized by using the following code.

Sort int_cntry by cntry.

Delete adjacent duplicates from int_cntry.

If NOT int_cntry[] is INITIAL.

Select * from zfligh appending table int_fligh

For all entries in int_cntry

Where cntry = int_cntry-cntry.

Endif.

Select Statements Select Over more than one Internal table

1. Its better to use a views instead of nested Select statements.

SELECT * FROM DD01L INTO DD01L_WA

WHERE DOMNAME LIKE 'CHAR%'

AND AS4LOCAL = 'A'.

SELECT SINGLE * FROM DD01T INTO DD01T_WA

WHERE DOMNAME = DD01L_WA-DOMNAME

AND AS4LOCAL = 'A'

AND AS4VERS = DD01L_WA-AS4VERS

AND DDLANGUAGE = SY-LANGU.

ENDSELECT.

The above code can be more optimized by extracting all the data from view DD01V_WA

SELECT * FROM DD01V INTO DD01V_WA

WHERE DOMNAME LIKE 'CHAR%'

AND DDLANGUAGE = SY-LANGU.

ENDSELECT

2. To read data from several logically connected tables use a join instead of nested Select statements. Joins are preferred only if all the primary key are available in WHERE clause for the tables that are joined. If the primary keys are not provided in join the Joining of tables itself takes time.

SELECT * FROM EKKO INTO EKKO_WA.

SELECT * FROM EKAN INTO EKAN_WA

WHERE EBELN = EKKO_WA-EBELN.

ENDSELECT.

The above code can be much more optimized by the code written below.

SELECT P_{F1 P}F2 F_{F3 F}F4 INTO TABLE ITAB

FROM EKKO AS P INNER JOIN EKAN AS F

ON P_{EBELN = F}EBELN.

3. Instead of using nested Select loops it is often better to use subqueries.

SELECT * FROM SPFLI

INTO TABLE T_SPFLI

WHERE CITYFROM = 'FRANKFURT'

AND CITYTO = 'NEW YORK'.

SELECT * FROM SFLIGHT AS F

INTO SFLIGHT_WA

FOR ALL ENTRIES IN T_SPFLI

WHERE SEATSOCC < F~SEATSMAX

AND CARRID = T_SPFLI-CARRID

AND CONNID = T_SPFLI-CONNID

AND FLDATE BETWEEN '19990101' AND '19990331'.

ENDSELECT.

The above mentioned code can be even more optimized by using subqueries instead of for all entries.

SELECT * FROM SFLIGHT AS F INTO SFLIGHT_WA

WHERE SEATSOCC < F~SEATSMAX

AND EXISTS ( SELECT * FROM SPFLI

WHERE CARRID = F~CARRID

AND CONNID = F~CONNID

AND CITYFROM = 'FRANKFURT'

AND CITYTO = 'NEW YORK' )

AND FLDATE BETWEEN '19990101' AND '19990331'.

ENDSELECT.

1. Table operations should be done using explicit work areas rather than via header lines.

READ TABLE ITAB INTO WA WITH KEY K = 'X‘ BINARY SEARCH.

IS MUCH FASTER THAN USING

READ TABLE ITAB INTO WA WITH KEY K = 'X'.

If TAB has n entries, linear search runs in O( n ) time, whereas binary search takes only O( log2( n ) ).

2. Always try to use binary search instead of linear search. But don’t forget to sort your internal table before that.

READ TABLE ITAB INTO WA WITH KEY K = 'X'. IS FASTER THAN USING

READ TABLE ITAB INTO WA WITH KEY (NAME) = 'X'.

3. A dynamic key access is slower than a static one, since the key specification must be evaluated at runtime.

4. A binary search using secondary index takes considerably less time.

5. LOOP ... WHERE is faster than LOOP/CHECK because LOOP ... WHERE evaluates the specified condition internally.

LOOP AT ITAB INTO WA WHERE K = 'X'.

" ...

ENDLOOP.

The above code is much faster than using

LOOP AT ITAB INTO WA.

CHECK WA-K = 'X'.

" ...

ENDLOOP.

6. Modifying selected components using “ MODIFY itab …TRANSPORTING f1 f2.. “ accelerates the task of updating a line of an internal table.

WA-DATE = SY-DATUM.

MODIFY ITAB FROM WA INDEX 1 TRANSPORTING DATE.

The above code is more optimized as compared to

WA-DATE = SY-DATUM.

MODIFY ITAB FROM WA INDEX 1.

7. Accessing the table entries directly in a "LOOP ... ASSIGNING ..." accelerates the task of updating a set of lines of an internal table considerably

Modifying selected components only makes the program faster as compared to Modifying all lines completely.

e.g,

LOOP AT ITAB ASSIGNING <WA>.

I = SY-TABIX MOD 2.

IF I = 0.

<WA>-FLAG = 'X'.

ENDIF.

ENDLOOP.

The above code works faster as compared to

LOOP AT ITAB INTO WA.

I = SY-TABIX MOD 2.

IF I = 0.

WA-FLAG = 'X'.

MODIFY ITAB FROM WA.

ENDIF.

ENDLOOP.

8. If collect semantics is required, it is always better to use to COLLECT rather than READ BINARY and then ADD.

LOOP AT ITAB1 INTO WA1.

READ TABLE ITAB2 INTO WA2 WITH KEY K = WA1-K BINARY SEARCH.

IF SY-SUBRC = 0.

ADD: WA1-VAL1 TO WA2-VAL1,

WA1-VAL2 TO WA2-VAL2.

MODIFY ITAB2 FROM WA2 INDEX SY-TABIX TRANSPORTING VAL1 VAL2.

ELSE.

INSERT WA1 INTO ITAB2 INDEX SY-TABIX.

ENDIF.

ENDLOOP.

The above code uses BINARY SEARCH for collect semantics. READ BINARY runs in O( log2(n) ) time. The above piece of code can be more optimized by

LOOP AT ITAB1 INTO WA.

COLLECT WA INTO ITAB2.

ENDLOOP.

SORT ITAB2 BY K.

COLLECT, however, uses a hash algorithm and is therefore independent

of the number of entries (i.e. O(1)) .

9. "APPEND LINES OF itab1 TO itab2" accelerates the task of appending a table to another table considerably as compared to “ LOOP-APPEND-ENDLOOP.”

APPEND LINES OF ITAB1 TO ITAB2.

This is more optimized as compared to

LOOP AT ITAB1 INTO WA.

APPEND WA TO ITAB2.

ENDLOOP.

10. “DELETE ADJACENT DUPLICATES“ accelerates the task of deleting duplicate entries considerably as compared to “ READ-LOOP-DELETE-ENDLOOP”.

DELETE ADJACENT DUPLICATES FROM ITAB COMPARING K.

This is much more optimized as compared to

READ TABLE ITAB INDEX 1 INTO PREV_LINE.

LOOP AT ITAB FROM 2 INTO WA.

IF WA = PREV_LINE.

DELETE ITAB.

ELSE.

PREV_LINE = WA.

ENDIF.

ENDLOOP.

11. "DELETE itab FROM ... TO ..." accelerates the task of deleting a sequence of lines considerably as compared to “ DO -DELETE-ENDDO”.

DELETE ITAB FROM 450 TO 550.

This is much more optimized as compared to

DO 101 TIMES.

DELETE ITAB INDEX 450.

ENDDO.

12. Copying internal tables by using “ITAB2[ ] = ITAB1[ ]” as compared to “LOOP-APPEND-ENDLOOP”.

ITAB2[] = ITAB1[].

This is much more optimized as compared to

REFRESH ITAB2.

LOOP AT ITAB1 INTO WA.

APPEND WA TO ITAB2.

ENDLOOP.

13. Specify the sort key as restrictively as possible to run the program faster.

“SORT ITAB BY K.” makes the program runs faster as compared to “SORT ITAB.”

Internal Tables contd…

Hashed and Sorted tables

1. For single read access hashed tables are more optimized as compared to sorted tables.

2. For partial sequential access sorted tables are more optimized as compared to hashed tables

Hashed And Sorted Tables

Point # 1

Consider the following example where HTAB is a hashed table and STAB is a sorted table

DO 250 TIMES.

N = 4 * SY-INDEX.

READ TABLE HTAB INTO WA WITH TABLE KEY K = N.

IF SY-SUBRC = 0.

" ...

ENDIF.

ENDDO.

This runs faster for single read access as compared to the following same code for sorted table

DO 250 TIMES.

N = 4 * SY-INDEX.

READ TABLE STAB INTO WA WITH TABLE KEY K = N.

IF SY-SUBRC = 0.

" ...

ENDIF.

ENDDO.

Point # 2

Similarly for Partial Sequential access the STAB runs faster as compared to HTAB

LOOP AT STAB INTO WA WHERE K = SUBKEY.

" ...

ENDLOOP.

This runs faster as compared to

LOOP AT HTAB INTO WA WHERE K = SUBKEY.

" ...

ENDLOOP.

Former Member · ‎12-04-2007

It would have been nice if you had shared the structure of EXTRACT detail because then we could have retrieved only the required fields instead of SELECT *. Never the less try this code and let me know if there was a performance improvement.

TABLES: ekko.

PARAMETERS : pr_werks LIKE ekpo-werks OBLIGATORY,
             pr_eindt LIKE eket-eindt OBLIGATORY.
SELECT-OPTIONS: s_lifnr FOR ekko-lifnr MATCHCODE OBJECT kred OBLIGATORY.

RANGES: r_eindt FOR eket-eindt.

DATA: w_eket     TYPE                 eket,
      w_ekpo     TYPE                 ekpo,
      w_ekko     TYPE                 ekko,
      w_makt     TYPE                 makt,
      w_lfa1     TYPE                 lfa1,
      w_found(1) TYPE                 c   ,

      t_eket     TYPE        TABLE OF eket,
      t_eket_tmp TYPE        TABLE OF eket,
      t_ekpo     TYPE HASHED TABLE OF ekpo
        WITH UNIQUE KEY ebeln ebelp,
      t_ekpo_tmp  TYPE        TABLE OF ekpo,
      t_ekko      TYPE HASHED TABLE OF ekko
        WITH UNIQUE KEY ebeln,
      t_ekko_tmp  TYPE        TABLE OF ekko,
      t_makt      TYPE HASHED TABLE OF makt
        WITH UNIQUE KEY matnr,
      t_lfa1      TYPE HASHED TABLE OF lfa1
        WITH UNIQUE KEY lifnr.

REFRESH r_eindt.

r_eindt-sign = 'I'.
r_eindt-option = 'BT'.
r_eindt-low    = pr_eindt.
r_eindt-high   = pr_eindt + 31.
APPEND r_eindt.
CLEAR  r_eindt.

SELECT *
  FROM eket
  INTO TABLE t_eket
  WHERE eindt IN r_eindt
  AND   menge NE 0.

IF sy-subrc EQ 0.

  SORT t_eket BY ebeln ebelp etenr.

  t_eket_tmp[] = t_eket[].

  DELETE ADJACENT DUPLICATES FROM t_eket_tmp COMPARING ebeln ebelp.

  SELECT *
    FROM ekpo
    INTO TABLE t_ekpo
    FOR ALL ENTRIES IN t_eket_tmp
    WHERE ebeln EQ t_eket_tmp-ebeln
    AND   ebelp EQ t_eket_tmp-ebelp
    AND   werks EQ pr_werks.

  IF sy-subrc EQ 0.

    t_ekpo_tmp[] = t_ekpo[].

    SORT t_ekpo_tmp BY ebeln.

    DELETE ADJACENT DUPLICATES FROM t_ekpo_tmp COMPARING ebeln.

    SELECT *
      FROM ekko
      INTO TABLE t_ekko
      FOR ALL ENTRIES IN t_ekpo_tmp
      WHERE ebeln EQ t_ekpo_tmp-ebeln
      AND   bstyp EQ 'L'
      AND   lifnr IN s_lifnr
      AND   frgke EQ 'R'.

    IF sy-subrc EQ 0.

      t_ekko_tmp[] = t_ekko[].

      SORT t_ekko_tmp BY lifnr.

      DELETE ADJACENT DUPLICATES FROM t_ekko_tmp COMPARING lifnr.

      SELECT *
        FROM lfa1
        INTO TABLE t_lfa1
        FOR ALL ENTRIES IN t_ekko_tmp
        WHERE lifnr EQ t_ekko_tmp-lifnr.

    ENDIF.

    t_ekpo_tmp[] = t_ekpo[].

    SORT t_ekpo_tmp BY matnr.

    DELETE ADJACENT DUPLICATES FROM t_ekpo_tmp COMPARING matnr.

    SELECT *
      FROM makt
      INTO TABLE t_makt
      FOR ALL ENTRIES IN t_ekpo_tmp
      WHERE matnr EQ t_ekpo_tmp-matnr
      AND   spras EQ sy-langu.

  ENDIF.


  LOOP AT t_eket INTO w_eket.

    AT NEW ebeln.

      READ TABLE t_ekko INTO w_ekko WITH KEY ebeln = w_eket-ebeln.

      IF sy-subrc EQ 0.

        READ TABLE t_lfa1 INTO w_lfa1 WITH KEY lifnr = w_ekko-lifnr.

        IF sy-subrc NE 0.
          CLEAR w_lfa1.
        ENDIF.

        w_found = 'X'.

      ELSE.

        CLEAR: w_found,
               w_ekko .

      ENDIF.

    ENDAT.

    AT NEW ebelp.

      READ TABLE t_ekpo INTO w_ekpo WITH KEY ebeln = w_eket-ebeln
                                             ebelp = w_eket-ebelp.
      IF sy-subrc EQ 0.

        READ TABLE t_makt INTO w_makt WITH KEY matnr = w_ekpo-matnr.

        IF sy-subrc NE 0.
          CLEAR w_makt.
        ENDIF.

      ELSE.

        CLEAR w_ekpo.

      ENDIF.

    ENDAT.


    CASE w_found.
      WHEN 'X'.

*   Add code here to populate the extract.

    ENDCASE.

  ENDLOOP.

ENDIF.

Message was edited by:

Mark Christian

Hello Experts please give some suggestions in this code