02-05-2008 11:46 AM
Hi Guys,
Is there any chance of improving the performance of these two select queries. This will be running in both fore ground and back ground. No chance of giving Material numbers. We will always exclude materials that starts with M(Exclude M*). User is getting timed out error if he run this report for 2 weeks in production.
SELECT objectclas objectid changenr username udate utime
planchngnr act_chngno change_ind
INTO TABLE i_cdhdr
FROM cdhdr
WHERE objectclas EQ c_mat
AND objectid IN so_matnr
AND udate IN so_udate.
IF NOT i_cdhdr[] IS INITIAL.
SORT i_cdhdr BY objectclas objectid changenr.
SELECT objectclas objectid changenr tabname tabkey fname
chngind text_case
INTO TABLE i_cdpos
FROM cdpos
FOR ALL ENTRIES IN i_cdhdr
WHERE objectclas EQ i_cdhdr-objectclas
AND objectid EQ i_cdhdr-objectid
AND changenr EQ i_cdhdr-changenr
AND tabname EQ c_mvke
AND fname EQ c_key
AND chngind IN (c_i, c_d).
ENDIF.
c_mat- 'MATERIAL'
so_matnr- Exclude M*
so_udate- Date range(Probably 2 weeks)
c_mvke- 'MVKE'
c_key-'KEY'
c_i-'I'
c_d-'D'.
Please let me know some solution for this. Also is there any function module available to get the above data. I am using 4.6C version.
Thanks in Advance,
Vinod.
02-05-2008 11:51 AM
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.
ENDSELECT.
The above code can be much more optimized by the code written below.
SELECT PF1 PF2 FF3 FF4 INTO TABLE ITAB
FROM EKKO AS P INNER JOIN EKAN AS F
ON PEBELN = FEBELN.
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.
ENDSELECT.
The above code can be much more optimized by the code written below.
SELECT PF1 PF2 FF3 FF4 INTO TABLE ITAB
FROM EKKO AS P INNER JOIN EKAN AS F
ON PEBELN = FEBELN.
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 dont 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.
02-05-2008 11:51 AM
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.
ENDSELECT.
The above code can be much more optimized by the code written below.
SELECT PF1 PF2 FF3 FF4 INTO TABLE ITAB
FROM EKKO AS P INNER JOIN EKAN AS F
ON PEBELN = FEBELN.
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.
ENDSELECT.
The above code can be much more optimized by the code written below.
SELECT PF1 PF2 FF3 FF4 INTO TABLE ITAB
FROM EKKO AS P INNER JOIN EKAN AS F
ON PEBELN = FEBELN.
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 dont 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.
02-05-2008 11:53 AM
Hi,
I dont have access to SAP system, you can check in the tcode se37 for the Fm. There are FM's which read data from CDHDR and CDPOS tables, first you just read the data from those tables then you can delete the unwanted data in CDPOS because you have your own where class. As per your code it is fine. No need to modify the code.
Rgds,
Bujji
02-05-2008 11:54 AM
Hi,
Try various queries and do performance tuning in transaction SE30.
Regards,
Renjith Michael.
02-05-2008 11:54 AM
You may want to have a look at the function modules:
CHANGEDOCUMENT_READ_HEADERS Change document: Read change document header
CHANGEDOCUMENT_READ_POSITIONS Change document: Read change document items
A similar program
REPORT ZSDCHANGE LINE-SIZE 132 NO STANDARD PAGE HEADING
LINE-COUNT 065(001)
MESSAGE-ID VR.
TABLES: DD04T,
CDHDR,
CDPOS,
DD03L,
DD41V,
T685T,
VBPA,
TPART,
KONVC,
VBUK.
DATA: BEGIN OF ICDHDR OCCURS 50.
INCLUDE STRUCTURE CDHDR.
DATA: END OF ICDHDR.
SELECT-OPTIONS: XUDATE FOR ICDHDR-UDATE,
XNAME FOR ICDHDR-USERNAME,
XVBELN FOR VBUK-VBELN.
SELECTION-SCREEN SKIP.
SELECTION-SCREEN BEGIN OF BLOCK BLK1 WITH FRAME TITLE TEXT-001.
PARAMETERS: SUDATE RADIOBUTTON GROUP R1,
SNAME RADIOBUTTON GROUP R1,
SOBID RADIOBUTTON GROUP R1.
SELECTION-SCREEN END OF BLOCK BLK1.
DATA: WFLAG,
WCHANGENR LIKE CDHDR-CHANGENR,
WUDATE LIKE CDHDR-UDATE,
WNAME LIKE CDHDR-USERNAME,
WVBELN LIKE VBUK-VBELN,
WDEC1 TYPE P DECIMALS 3,
WDEC2 TYPE P DECIMALS 3,
WDEC3 TYPE P DECIMALS 3,
WDEC4 TYPE P DECIMALS 3.
DATA: UTEXT(16) VALUE 'has been changed',
ITEXT(16) VALUE 'has been created',
DTEXT(16) VALUE 'has been deleted'.
DATA: BEGIN OF ICDSHW OCCURS 50.
INCLUDE STRUCTURE CDSHW.
DATA: END OF ICDSHW.
DATA: BEGIN OF ITAB OCCURS 10.
INCLUDE STRUCTURE CDSHW.
DATA: UDATE LIKE CDHDR-UDATE,
USERNAME LIKE CDHDR-USERNAME,
CHANGENR LIKE CDHDR-CHANGENR,
VBELN(10),
POSNR(6),
ETENR(4),
INDTEXT(200),
END OF ITAB.
SELECT * FROM VBUK WHERE VBELN IN XVBELN.
CLEAR CDHDR.
CLEAR CDPOS.
CDHDR-OBJECTCLAS = 'VERKBELEG'.
CDHDR-OBJECTID = VBUK-VBELN.
PERFORM READHEADER.
PERFORM READPOS.
LOOP AT ITAB.
CASE ITAB-TABNAME.
WHEN 'VBPA'.
IF ITAB-FNAME = 'KUNNR' OR
ITAB-FNAME = 'LIFNR' OR
ITAB-FNAME = 'PARNR' OR
ITAB-FNAME = 'PERNR' OR
ITAB-FNAME IS INITIAL.
MOVE ITAB-TABKEY TO VBPA.
SELECT SINGLE * FROM TPART WHERE SPRAS = SY-LANGU
AND PARVW = VBPA-PARVW.
IF SY-SUBRC = 0.
REPLACE '&' WITH TPART-VTEXT INTO ITAB-INDTEXT.
ENDIF.
ENDIF.
WHEN 'VBAP'.
IF ITAB-FNAME IS INITIAL.
REPLACE '&' WITH 'Item' INTO ITAB-INDTEXT.
ENDIF.
WHEN 'KONVC'.
MOVE ITAB-TABKEY TO KONVC.
SELECT SINGLE * FROM T685T WHERE SPRAS = SY-LANGU
AND KVEWE = 'A'
AND KAPPL = 'V'
AND KSCHL = KONVC-KSCHL.
IF SY-SUBRC = 0.
REPLACE '&' WITH T685T-VTEXT INTO ITAB-INDTEXT.
ENDIF.
ENDCASE.
IF ITAB-INDTEXT(1) EQ '&'.
REPLACE '&' WITH ITAB-FTEXT(40) INTO ITAB-INDTEXT.
ENDIF.
IF ITAB-CHNGIND = 'I'.
REPLACE '%' WITH ITEXT INTO ITAB-INDTEXT.
ELSEIF ITAB-CHNGIND = 'U'.
REPLACE '%' WITH UTEXT INTO ITAB-INDTEXT.
ELSE.
REPLACE '%' WITH DTEXT INTO ITAB-INDTEXT.
ENDIF.
CONDENSE ITAB-INDTEXT.
MODIFY ITAB.
ENDLOOP.
ENDSELECT.
IF SUDATE = 'X'.
SORT ITAB BY UDATE VBELN POSNR ETENR.
ELSEIF SOBID = 'X'.
SORT ITAB BY VBELN POSNR ETENR UDATE.
ELSE.
SORT ITAB BY USERNAME VBELN POSNR ETENR UDATE.
ENDIF.
LOOP AT ITAB.
CLEAR WFLAG.
IF SUDATE = 'X'.
IF WUDATE NE ITAB-UDATE.
SKIP.
WRITE:/001 ITAB-UDATE,
023 ITAB-USERNAME,
037(10) ITAB-VBELN.
WFLAG = 'X'.
WUDATE = ITAB-UDATE.
WCHANGENR = ITAB-CHANGENR.
ENDIF.
ELSEIF SOBID NE 'X'.
IF WVBELN NE ITAB-VBELN.
SKIP.
WRITE:/001 ITAB-VBELN.
WVBELN = ITAB-VBELN.
ENDIF.
ELSE.
IF WNAME NE ITAB-USERNAME.
SKIP.
WRITE:/001 ITAB-USERNAME.
WNAME = ITAB-USERNAME.
ENDIF.
ENDIF.
IF WCHANGENR NE ITAB-CHANGENR.
WRITE:/023 ITAB-USERNAME,
037(10) ITAB-VBELN.
WFLAG = 'X'.
WCHANGENR = ITAB-CHANGENR.
ENDIF.
IF WFLAG = 'X'.
WRITE: 013 ITAB-CHNGIND,
049 ITAB-POSNR,
057 ITAB-ETENR,
065 ITAB-INDTEXT(60).
ELSE.
WRITE: /013 ITAB-CHNGIND,
049 ITAB-POSNR,
057 ITAB-ETENR,
065 ITAB-INDTEXT(60).
ENDIF.
WRITE:/065 ITAB-F_OLD.
WRITE:/065 ITAB-F_NEW.
ENDLOOP.
FORM READHEADER.
CALL FUNCTION 'CHANGEDOCUMENT_READ_HEADERS'
EXPORTING
DATE_OF_CHANGE = CDHDR-UDATE
OBJECTCLASS = CDHDR-OBJECTCLAS
OBJECTID = CDHDR-OBJECTID
TIME_OF_CHANGE = CDHDR-UTIME
USERNAME = CDHDR-USERNAME
TABLES
I_CDHDR = ICDHDR
EXCEPTIONS
NO_POSITION_FOUND = 1
OTHERS = 2.
CASE SY-SUBRC.
WHEN '0000'.
WHEN '0001'.
MESSAGE S311.
LEAVE.
WHEN '0002'.
MESSAGE S311.
LEAVE.
ENDCASE.
ENDFORM.
FORM READPOS.
LOOP AT ICDHDR.
CHECK ICDHDR-UDATE
IN XUDATE.
CHECK ICDHDR-USERNAME
IN XNAME.
CALL FUNCTION 'CHANGEDOCUMENT_READ_POSITIONS'
EXPORTING
CHANGENUMBER = ICDHDR-CHANGENR
TABLEKEY = CDPOS-TABKEY
TABLENAME = CDPOS-TABNAME
IMPORTING
HEADER = CDHDR
TABLES
EDITPOS = ICDSHW
EXCEPTIONS
NO_POSITION_FOUND = 1
OTHERS = 2.
CASE SY-SUBRC.
WHEN '0000'.
LOOP AT ICDSHW.
CHECK ICDSHW-CHNGIND NE 'E'.
CLEAR ITAB.
MOVE-CORRESPONDING ICDHDR TO ITAB.
MOVE-CORRESPONDING ICDSHW TO ITAB.
CASE ITAB-TABNAME.
WHEN 'KONVC'.
MOVE ICDHDR-OBJECTID TO ITAB-VBELN.
MOVE ICDSHW-TABKEY(6) TO ITAB-POSNR.
WHEN OTHERS.
MOVE ICDSHW-TABKEY+3(10) TO ITAB-VBELN.
MOVE ICDSHW-TABKEY+13(6) TO ITAB-POSNR.
MOVE ICDSHW-TABKEY+19(4) TO ITAB-ETENR.
ENDCASE.
MOVE '& %' TO ITAB-INDTEXT.
APPEND ITAB.
CLEAR ITAB.
ENDLOOP.
WHEN OTHERS.
MESSAGE S311.
LEAVE.
ENDCASE.
ENDLOOP.
ENDFORM.
TOP-OF-PAGE.
WRITE:/ SY-DATUM,SY-UZEIT,
50 'SALES ORDER CHANGE HISTORY',
120 'Page', SY-PAGNO.
WRITE: / SY-REPID,
60 'SALES ORDERS STATISTICS'.
SKIP.
ULINE.
IF SUDATE = 'X'.
WRITE:/001 'Change Date',
013 'Time',
023 'User Name',
037 'Sale Order',
049 'Line',
057 'Sch No',
065 'Changes'.
ELSEIF SOBID = 'X'.
WRITE:/001 'Sale Order',
013 'Line',
021 'Sch No',
029 'Change Date',
041 'Time',
051 'User Name',
065 'Comment'.
ELSE.
WRITE:/001 'User Name',
015 'Time',
025 'Change Date',
037 'Sale Order',
049 'Line',
057 'Sch No',
065 'Changes'.
ENDIF.
ULINE.
*--- End of Program
Regards,
02-05-2008 11:55 AM
Hi,
You can make use of indexes for faster performances.
e.g
SELECT objectid changenr username udate utime INTO TABLE g_t_cdhdr1
FROM cdhdr
FOR ALL ENTRIES IN g_t_so_cond
WHERE objectclas = c_cond_a AND
objectid = g_t_so_cond-objectid AND
username IN s_user AND
udate IN r_date
%_HINTS ORACLE 'INDEX("CDHDR" "CDHDR~Z2")'.
<REMOVED BY MODERATOR>
Regards,
Mansi.
Edited by: Alvaro Tejada Galindo on Feb 5, 2008 5:49 PM
02-05-2008 2:33 PM
I doubt if there's much you can do - run it in the background only.
Rob
02-08-2008 11:24 AM
Hi Guys,
Is there any chance in improving the performance. Requirement is to run both in fore ground and back ground.
Thanks in advance,
Vinod.
03-10-2008 3:03 PM