Select Query Scenario

Hi all,
I have a select query scenario.
For example in a ztable
I have two fields A and B
it holds records like
A     B
3     5
2     10
7     12
if my input is 4
I wrote a query like
select * from ztab where ( a <= input and b >= input ).
But its not working
The problem is its picking both the record
3     5
2     10
but my output should be
3     5
Hope its clear ..
I know that this could be acheived using a select and a delete from itab.
But i need to acheive this through single select.
Any ideas ..

Hi,
If the data comes from a Z table and the fields are numeric by nature (as the name "bankkey" might imply), then I would really recommend adapting the data type in the table, making the fields numeric. Working around the data type in your code (which technically you coudl do by a MOVE from the C field to a numeric field) would be clumsy and you'd have to do it in every program thet accesses this data.
Regards,
Mark

Similar Messages

Select query in materialized view with two dblinks

Hi All,
We have oracle 10g On windows.
We are trying to create materialized view. Scenario is we have base table on other database and we are creating mview on different database.
Basa database have two schema's and i am selecting records from that two schema's using two private db links.
But when i am tryin gto create mview its not getting created. After 15 hrs. its still showing creation command and not finished.
Query is :-
Is it good practice to have two db links in select query of materialized view.

Billy Verreynne wrote:
Chanchal Wankhade wrote:
Is it good practice to have two db links in select query of materialized view.Same db link being used twice, or two different db links?
If the former, you ideally want the local Oracle db to send the join to the remote database, and for the remote database to drive the join between those 2 tables. There is a hint (<i>driving_site</i>) that can be used - or the join query can be defined on the remote database as a view, and the local materialised view can then use that remote view.
If you have 2 different db links and joining across these - usually a bad idea to perform distributed database joins. There are lots of limitations as to how the tables can be joined. Worse case, full table scans of both remote tables, pulling all the rows from the 2 remote database tables to the local database, and joining these on the local database.
I have seen some severe performance issues in the past as a result of distributed joins. I'll rather use 2 materialised views for pulling both distributed tables's data locally, and then do the join on local data (using indexes, partition pruning, etc)Hi Billy,
My scenario is i have two database database A and database B. Database A is having two schema's SCOTT AND HR. SCOTT schema have select privileges on HR schema.
DB LINK is between Database B to Database A. name is db.link.B.A.oracle.com.
What if i priovide while creating materialized view, the schema name before the table name in database B for this particuler table so it will pick up the table from that schema using same DB LINK(db.link.B.A.oracle.com.) that i am using to fetch records from SCOTT schema.
Above schnario is like two base schema's and one db link using two schema.

How can i use index in select query.. facing problem with the select query.

Hi Friends,
I am facing a serious problem in one of the select query. It is taking a lot of time to fetch data in Production Scenario.
Here is the query:
SELECT * APPENDING CORRESPONDING FIELDS OF TABLE tbl_summary
    FROM ztftelat LEFT JOIN ztfzberep
     ON ztfzberep~gjahr = st_input-gjahr
     AND ztfzberep~poper = st_input-poper
     AND ztfzberepcntr = ztftelatrprctr
    WHERE rldnr = c_telstra_accounting
      AND rrcty = c_actual
      AND rvers = c_ver_001
      AND rbukrs = st_input-bukrs
      AND racct = st_input-saknr
      AND ryear = st_input-gjahr
      And rzzlstar in r_lstar
      AND rpmax = c_max_period.
There are 5 indices present for Table ZTFTELAT.
Indices of ZTFTELAT:
Name   Description
0        Primary key( RCLNT,RLDNR,RRCTY,RVERS,RYEAR,ROBJNR,SOBJNR,RTCUR,RUNIT,DRCRK,RPMAX)
005    Profit (RCLNT,RPRCTR)
1        Ledger, company code, account (RLDNR,RBUKRS, RACCT)
2        Ledger, company code, cost center (RLDNR, RBUKRS,RCNTR)
3        Account, cost center (RACCT,RCNTR)
4        RCLNT/RLDNR/RRCTY/RVERS/RYEAR/RZZAUFNR
Z01    Activity Type, Account (RZZLSTAR,RACCT)
Z02    RYEAR-RBUKRS- RZZZBER-RLDNR
Can anyone help me out why it is taking so much time and how we can reduce it ? and also tell me if I want to use index number 1 then how can I use?
Thanks in advance.

Hi Shiva,
I am using two more select queries with the same manner ....
here are the other two select query :
***************1************************
SELECT * APPENDING CORRESPONDING FIELDS OF TABLE tbl_summary
    FROM ztftelpt LEFT JOIN ztfzberep
     ON ztfzberep~gjahr = st_input-gjahr
     AND ztfzberep~poper = st_input-poper
     AND ztfzberepcntr = ztftelptrprctr
    WHERE rldnr = c_telstra_projects
      AND rrcty = c_actual
      AND rvers = c_ver_001
      AND rbukrs = st_input-bukrs
      AND racct = st_input-saknr
      AND ryear = st_input-gjahr
      and rzzlstar in r_lstar
      AND rpmax = c_max_period.
and the second one is
*************************2************************
SELECT * APPENDING CORRESPONDING FIELDS OF TABLE tbl_summary
    FROM ztftelnt LEFT JOIN ztfzberep
     ON ztfzberep~gjahr = st_input-gjahr
     AND ztfzberep~poper = st_input-poper
     AND ztfzberepcntr = ztftelntrprctr
    WHERE rldnr = c_telstra_networks
      AND rrcty = c_actual
      AND rvers = c_ver_001
      AND rbukrs = st_input-bukrs
      AND racct = st_input-saknr
      AND ryear = st_input-gjahr
      and rzzlstar in r_lstar
      AND rpmax = c_max_period.
for both the above table program is taking very less time .... although both the table used in above queries have similar amount of data. And i can not remove the APPENDING CORRESPONDING. because i have to append the data after fetching from the tables. if i will not use it will delete all the data fetched earlier.
Thanks on advanced......
Sourabh

Select query problem in JDBC sender adapter

Hello Experts,
We have a problem with PI sender adapter that PI has started to miss records in database some database records are missing and we are using the below selet query :
SELECT * FROM [database name].[dbo].[Material_Movement] WHERE [Process_Order_Number] = (Select TOP 1 [Process_Order_Number] FROM [database name].[dbo].[Material_Movement] WHERE ([PI_Read_Date] IS NULL AND [Movement_Type] = (SELECT TOP 1 [Movement_Type] FROM [database name].[dbo].[Material_Movement] WHERE [Transaction_Code] = 'xyz' AND [PI_Read_Date] IS NULL ORDER BY Created_Date ASC))) AND [Transaction_Code] = 'xyz' AND [Movement_Type] = (SELECT TOP 1 [Movement_Type] FROM [database name].[dbo].[Material_Movement] WHERE [Transaction_Code] = 'xyz' AND [PI_Read_Date] IS NULL ORDER BY Created_Date ASC) AND [PI_Read_Date] IS NULL ORDER BY [Transaction_ID] ASC
I am weak in select query could you please check and suggest how the query can be modified to avoid this issue .
Thanks,
Somenath

Hi ,
After looking into These Query .. I found ...
Your Query Will run such Kind of scenario ..
1.)   Movement Type will be fetched from from below Query
        SELECT TOP 1 Movement_Type
        FROM database name.dbo.Material_Movement
        WHERE Transaction_Code = 'xyz'
       AND PI_Read_Date IS NULL
        ORDER BY Created_Date ASC
2.) on the basis of abovr fetched moment code . your Query will fetch 1 Process Order number
Select TOP 1 Process_Order_Number
FROM database name.dbo.Material_Movement
WHERE ( PI_Read_Date IS NULL
              AND Movement_Type = Moment Type will be same as 1.
3.)
After Getting 1 and 2 . Query will fetch Data from table " dbo.Material_Movement "
On the basis of ..
Movement_Type = value from 1.
Process_order_type = value from 2.
Transaction_Code = 'xyz'
ORDER BY Transaction_ID ASC
So check Missed record Fullfill this Condition or not ....................
If not ... You will get why they are not picked by your given Query ...........
Hope it helps ..
regards
Prabhat Sharma.

Select query performance improvement - Index on EDIDC table

Hi Experts,
I have a scenario where in I have to select data from the table EDIDC. The select query being used is given below.
SELECT docnum
          direct
          mestyp
          mescod
          rcvprn
          sndprn
          upddat
          updtim
INTO CORRESPONDING FIELDS OF TABLE t_edidc
FROM edidc
FOR ALL ENTRIES IN t_error_idoc
WHERE
upddat GE gv_date1 AND
upddat LE gv_date2 AND
updtim GE p_time AND
status EQ t_error_idoc-status.
As the volume of the data is very high, our client requested to put up some index or use an existing one to improve the performance of the data selection query.
Question:
4.    How do we identify the index to be used.
5.    On which fields should the indexing be done to improve the performance (if available indexes donu2019t cater to our case).
6.    What will be the impact on the table performance if we create a new index.
Regards ,
Raghav

Question:
1.    How do we identify the index to be used.
Generally the index is automatically selected by SAP (DB Optimizer ) ( You can still mention the index name in your select query by changing the syntax)
For your select Query the second Index will be called automatically by the Optimizer, ( Because the select query has u2018Updatu2019 , u2018uptimu2019 in the sequence before the u2018statusu2019 ) .
2.    On which fields should the indexing be done to improve the performance (if available indexes donu2019t cater to our case).
(Create a new Index with MANDT and the 4 fields which are in the where clause in sequence )
3.    What will be the impact on the table performance if we create a new index.
( Since the index which will be newly created is only the 4th index for the table, there shouldnu2019t be any side affects)
After creation of index , Check the change in performance of the current program and also some other programs which are having the select queries on EDIDC ( Various types of where clauses preferably ) to verify that the newly created index is not having the negative impact on the performance. Additionally, if possible , check if you can avoid into corresponding fields .
Regards ,
Seth

Select Query in FM

I am working on a function module.
The input to the function is more one entry.... (zz1, zz2, zz3)...
Based on the input i have to write a select query
select f1
           f2
           from DBtable into table itab2
           for all entries in itab2 where
           f1 eq itab1-f1 and
           f3 ge sy-datum.
here f 1 is zz1,zz2,zz3.
However if the user enters z* in the input then also this select query in the FM should work.How to achieve this..Thank you.

Hi Karthik,
I hope following code will solve your problem. Here, it_itab should be your table declared in the interface of your your function module. Use should pass zz1,zz2 to it_itab. Here, I have taken only three fields and written the code. You will have to tweak it a bit to suit your scenario. So, based on the entries in the it_itab, your fields that need to be selected from the database and condition to be evaluated will be generated dynamically.
TYPES : BEGIN OF x_itab,
          field TYPE string,
        END   OF x_itab.
DATA : it_itab TYPE TABLE OF x_itab,
       it_vbak TYPE TABLE OF vbak,
       x_itab TYPE x_itab,
       v_select TYPE string,
       v_condition TYPE string.
LOOP AT it_itab INTO x_itab.
IF sy-tabix = 1.
    v_select = x_itab-field.
ELSE.
    CONCATENATE v_select x_itab-field INTO v_select SEPARATED BY space.
ENDIF.
CASE x_itab-field.
    WHEN 'VBELN'.
      IF sy-tabix = 1.
        v_condition = 'VBELN = X_ITAB-FIELD'.
      ELSE.
    CONCATENATE v_condition 'AND VBELN = X_ITAB-FIELD' INTO v_condition
SEPARATED BY space.
      ENDIF.
    WHEN 'ERNAM'.
      IF sy-tabix = 1.
        v_condition = 'ERNAM = X_ITAB-FIELD'.
      ELSE.
    CONCATENATE v_condition 'AND ERNAM = X_ITAB-FIELD' INTO v_condition
SEPARATED BY space.
      ENDIF.
    WHEN 'ERDAT'.
      IF sy-tabix = 1.
        v_condition = 'ERDAT > 20070405'.
      ELSE.
        CONCATENATE v_condition 'AND ERDAT > 20070405' INTO v_condition
   SEPARATED BY space.
      ENDIF.
ENDCASE.
ENDLOOP.
CONCATENATE v_condition '.' INTO v_condition.
SELECT (v_select)
FROM vbak
INTO CORRESPONDING FIELDS OF TABLE it_vbak
WHERE (v_condition).
Reward points if the answer is helpful.
Regards,
Mukul

Two select query in sender JDBC adaptor

Hi
We are doing JDFC-RFC scenario, in which i need to fetch the data from two tables (header and item table) whch correspondes to the 2 table parameter of RFC .
Any clues how to configure sender jdbc CC having 2 select query ??????
Regards
Vijay

Swatantra,
You can have a look at the below URL for more info on JOIN.
http://www.w3schools.com/sql/sql_join.asp
Best regards,
raj.

Sinlge select query in different schemas for same table(Indentical Structu)

Scenario :
Table XYZ is created in Schema A
After an year, the old data from the previous year would be moved to different schema. However in the other schema the same table name would be used.
For eg
Schema A contains table XYZ with data of 2012 yr
Schema B contains table XYZ with data of 2011 yr
Table XYZ in both the schemas have identical structure.
So can we fire a single select query to read the data from both the tables in effective way.
Eg select * from XYZ where date range between 15-Oct-2011 to 15-Mar-2012.
However the data resides in 2 different schema altogether.

Thanks for the reply
Creating an view is an option.
But my problem, there is ORM layer(either Hibernate or Eclipse Top Link) between the application and the database.
So the queries would be formed by the ORM layer and are not hand generated.
So i cannot use view.
So is there any option that would allow me to use single query on different schema's ?

Sinlge select query in diff schemas for same table(Indentical Structure)

Scenario :
Table XYZ is created in Schema A
After an year, the old data from the previous year would be moved to different schema. However in the other schema the same table name would be used.
For eg
Schema A contains table XYZ with data of 2012 yr
Schema B contains table XYZ with data of 2011 yr
Table XYZ in both the schemas have identical structure.
So can we fire a single select query to read the data from both the tables in effective way.
Eg select * from XYZ where date range between 15-Oct-2011 to 15-Mar-2012.
However the data resides in 2 different schema altogether.
Creating an view is an option.
But my problem, there is ORM layer(either Hibernate or Eclipse Top Link) between the application and the database.
So the queries would be formed by the ORM layer and are not hand generated.
So i cannot use view.
So is there any option that would allow me to use single query on different schema's ?

Hi,
970773 wrote:
Scenario :
Table XYZ is created in Schema A
After an year, the old data from the previous year would be moved to different schema. However in the other schema the same table name would be used.
For eg
Schema A contains table XYZ with data of 2012 yr
Schema B contains table XYZ with data of 2011 yr
Table XYZ in both the schemas have identical structure.
So can we fire a single select query to read the data from both the tables in effective way.That depends on what you mean by "effective".
Eg select * from XYZ where date range between 15-Oct-2011 to 15-Mar-2012.
However the data resides in 2 different schema altogether.You can do a UNION, so the data from the two years appears together. The number of actual tables may make the query slower, but it won;t change the results.
Given that you have 2 tables, the fact that they are in different schemas doesn't matter. Just make sure the user running the query has SELECT privileges on both of them.
Creating an view is an option.Is it? You seem to say it is not, below.
But my problem, there is ORM layer(either Hibernate or Eclipse Top Link) between the application and the database.
So the queries would be formed by the ORM layer and are not hand generated.
So i cannot use view.So creating a view is not an option. Or is it?
So is there any option that would allow me to use single query on different schema's ?Anything that you can do with a view, you can do with sub-queries. A view is merely a convenience; it just saves a sub-query, so you don't have to re-code it every time you use it. Assuming you have privilges to query the base tables, you can always avoid using a view by repeating the query that defines the view in your own query. It will not be any slower

SELECT query takes too much time! Y?

Plz find my SELECT query below:
select w~mandt
wvbeln wposnr wmeins wmatnr wwerks wnetwr
wkwmeng wvrkme wmatwa wcharg w~pstyv
wposar wprodh wgrkor wantlf wkztlf wlprio
wvstel wroute wumvkz wumvkn wabgru wuntto
wawahr werdat werzet wfixmg wprctr wvpmat
wvpwrk wmvgr1 wmvgr2 wmvgr3 wmvgr4 wmvgr5
wbedae wcuobj w~mtvfp
xetenr xwmeng xbmeng xettyp xwepos xabart
x~edatu
xtddat xmbdat xlddat xwadat xabruf xetart
x~ezeit
into table t_vbap
from vbap as w
inner join vbep as x on xvbeln = wvbeln and
xposnr = wposnr and
xmandt = wmandt
where
( ( werdat > pre_dat ) and ( werdat <= w_date ) ) and
( ( ( erdat > pre_dat and erdat < p_syndt ) or
( erdat = p_syndt and erzet <= p_syntm ) ) ) and
w~matnr in s_matnr and
w~pstyv in s_itmcat and
w~lfrel in s_lfrel and
w~abgru = ' ' and
w~kwmeng > 0 and
w~mtvfp in w_mtvfp and
x~ettyp in w_ettyp and
x~bdart in s_req_tp and
x~plart in s_pln_tp and
x~etart in s_etart and
x~abart in s_abart and
( ( xlifsp in s_lifsp ) or ( xlifsp = ' ' ) ).
The problem: It takes too much time while executing this statement.
Could anybody change this statement and help me out to reduce the DB Access time?
Thx

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.

Performance Tuning on a Select Query

Hi,
We have a select statement as mentioned below.
      SELECT loobj1 gpart vkont proid tdate lotyp lockr
      INTO TABLE tb_dfkklocks
         FROM dfkklocks
         FOR ALL ENTRIES IN tb_fkkvkp
         WHERE
        lotyp = '02'
         AND   proid = '01'
         AND   lockr >= '0'
         AND   lockr <= '9'
         AND   gpart = tb_fkkvkp-gpart
         AND   vkont = tb_fkkvkp-vkont.
We have Primary key as shown below.
CLIENT
LOOBJ1
LOTYP
PROID
LOCKR
FDATE
TDATE
GPART
VKONT
We have a secondary index only on TDATE. What can be the ideal select stement to improve the performance?
Regards,
Lijo Joseph

Hi Lijo,
Couple of pointers from my end.
1). Try avoiding a FOR ALL ENTRIES if the base table is huge. Instead use a array fetch and pick up more data instead of trying to restrict the data using a FOR ALL ENTRIES as this does a LOOP on the database while selecting the data.
So i would suggest not use FOR ALL ENTRIES if the base table is huge. So analyse before using a select query.
2). It is actually very difficult to mention which option is better. I would say that it all depends on the scenario. What amount of data is to be read, from which table it is being read, what kind of processing is required on database,..... and many more analysis goes to write a an efficient select statement.
3). If i am not wrong i think if you are using a FOR ALL ENTRIES and dont specify the key completely then there is no gaurentee that you fetch all the unique records. The system will compare all the character fields as a KEY field and it will not fetch all the records. So while using a FOR ALL ENTRIES its recommended to use all the key fields.
4). If you would like to really spend time and work on a efficient select statement then try using the tcode ST05 --> Select the button EXPLAIN SQL REQUEST.
type in your select query and see what is the cost of the select statement fired on the database. This will help you to select the best statement. This is a very useful tool if we have complex select statements.
Hope this info is helpful.
Cheers
VJ
Message was edited by: Vijayendra Rao

Regarding to perform in select query

could any tell the select query in this piece of code would affect the performance of the programe
DATA: BEGIN OF OUTREC,
      BANKS LIKE BNKA-BANKS,
      BANKL LIKE BNKA-BANKL,
      BANKA LIKE BNKA-BANKA,
      PROVZ LIKE BNKA-PROVZ,   "Region (State, Province, County)
      BRNCH LIKE BNKA-BRNCH,
      STRAS LIKE BNKA-STRAS,
      ORT01 LIKE BNKA-ORT01,
      SWIFT LIKE BNKA-SWIFT,
END OF OUTREC.
OPEN DATASET P_OUTPUT FOR OUTPUT IN TEXT MODE.
IF SY-SUBRC NE 0. EXIT. ENDIF.
SELECT * FROM BNKA
         WHERE BANKS EQ P_BANKS
         AND   LOEVM NE 'X'
         AND   XPGRO NE 'X'
         ORDER BY BANKS BANKL.
PERFORM TRANSFER_DATA.
ENDSELECT.
CLOSE DATASET P_OUTPUT.
*&      Transfer the data to the output file
FORM TRANSFER_DATA.
OUTREC-BANKS = BNKA-BANKS.
OUTREC-BANKL = BNKA-BANKL.
OUTREC-BANKA = BNKA-BANKA.
OUTREC-PROVZ = BNKA-PROVZ.
OUTREC-BRNCH = BNKA-BRNCH.
OUTREC-STRAS = BNKA-STRAS.
OUTREC-ORT01 = BNKA-ORT01.
OUTREC-SWIFT = BNKA-SWIFT.
TRANSFER OUTREC TO P_OUTPUT.
ENDFORM.                               " READ_IN_DATA

Hi
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.
Points # 1/2
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
2.     Select all the records in a single shot using into table clause of select statement rather than to use Append statements.
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.
4.     For testing existence , use Select.. Up to 1 rows statement instead of a Select-Endselect-loop with an Exit.
5.     Use Select Single if all primary key fields are supplied in the Where condition .
Point # 1
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.
Point # 2
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'.
Point # 3
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.
Point # 4
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.
Point # 5
If all primary key fields are supplied in the Where condition you can even use Select Single.
Select Single requires one communication with the database system, whereas Select-Endselect needs two.
Select Statements           contd.. SQL Interface
1.     Use column updates instead of single-row updates
to update your database tables.
2.     For all frequently used Select statements, try to use an index.
3.     Using buffered tables improves the performance considerably.
Point # 1
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.
Point # 2
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.
Point # 3
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       contd           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    contdFor 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    contd Select Over more than one Internal table
1.     Its better to use a views instead of nested Select statements.
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.
3.     Instead of using nested Select loops it is often better to use subqueries.
Point # 1
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
Point # 2
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.
Point # 3
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.
2.     Always try to use binary search instead of linear search. But dont forget to sort your internal table before that.
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.
6.     Modifying selected components using MODIFY itab TRANSPORTING f1 f2.. accelerates the task of updating a line of an internal table.
Point # 2
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 ) ).
Point # 3
READ TABLE ITAB INTO WA WITH KEY K = 'X'. IS FASTER THAN USING
READ TABLE ITAB INTO WA WITH KEY (NAME) = 'X'.
Point # 5
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.
Point # 6
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
8.    If collect semantics is required, it is always better to use to COLLECT rather than READ BINARY and then ADD.
9.    "APPEND LINES OF itab1 TO itab2" accelerates the task of appending a table to another table considerably as compared to LOOP-APPEND-ENDLOOP.
10.   DELETE ADJACENT DUPLICATES accelerates the task of deleting duplicate entries considerably as compared to READ-LOOP-DELETE-ENDLOOP.
11.   "DELETE itab FROM ... TO ..." accelerates the task of deleting a sequence of lines considerably as compared to DO -DELETE-ENDDO.
Point # 7
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.
Point # 8
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)) .
Point # 9
APPEND LINES OF ITAB1 TO ITAB2.
This is more optimized as compared to
LOOP AT ITAB1 INTO WA.
APPEND WA TO ITAB2.
ENDLOOP.
Point # 10
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.
Point # 11
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.
13.   Specify the sort key as restrictively as possible to run the program faster.
Point # 12
ITAB2[] = ITAB1[].
This is much more optimized as compared to
REFRESH ITAB2.
LOOP AT ITAB1 INTO WA.
APPEND WA TO ITAB2.
ENDLOOP.
Point # 13
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.

Select query that eliminate duplicates

I am struck at the below scenario. need your help in modify my query based on the below sample data. My objective is to create a EVENT AND EVENT_LOW using the data available from TEM_GT and TXN table.
TEM_GT (global temporary table)
est_id primary key, trans_id, trp_id, amount
1 111 2221 1.5
2 111 3332 2.0
3 112 4443 3.0
TXN table
trans_id, trans_type
111 type1
112 type1
EVENT table
event_id primary key, trans_id, trans_type, flag.
1000 111 type1 N
1001 112 type1 N
EVENT_LOW table
event_low_id primary key, event_id, est_id, amount.
9991 1000 1 1.5
9992 1000 1 2.0
9993 1001 2 3.0
insert into(event_low_id, event_id, est_id, amount)
select event_low_id_s.nextval e.event_id, tg.est_id, tg.amount from
from TEM_GT tg, EVENT e
WHERE
tg.trans_id = e.trans_id
AND e.flag = 'N'
Based on TEM_GT and TXN gt, populating data into EVENT table. Now when I try to populate data in the EVENT_LOW table, the above query returns 5 rows instead of 3 rows. This is due to trp_id in TEM_GT table. I do not want to add trp_id in EVENT table, and want to handle the duplicate elimination in the above select query.
I wrote the below sql. It almost resolve my problem. But sometimes it returns different value for the amount column. I wanted my event_low result as below for the est_id 1.
event_low_id primary key, event_id, est_id, amount.
9991 1000 1 1.5
9992 1000 1 2.0
But sometime it returns as below
event_low_id primary key, event_id, est_id, amount.
9991 1000 1 1.5
9992 1000 1 1.5
or
event_low_id primary key, event_id, est_id, amount.
9991 1000 1 2.0
9992 1000 1 2.0
select *
from (select x.*,
row_number() over (partition by event_id order by event_id) rn
from (seelct e.event_id, tg.est_id, tg.amount
from TEM_GT tg, EVENT e
WHERE
tg.trans_id = e.trans_id
AND e.flag = 'N'
) x
where rn = 1
I am using Oracle 11g. Any help. Thanks in advance.

Hi Suresh,
Please read SQL and PL/SQL FAQ
Whenever you create a thread always post sample data as CREATE TABLE and INSERT statements.
Additionally when you put some code or output please enclose it between two lines starting with {noformat}{noformat}
i.e.:
{noformat}{noformat}
SELECT ...
{noformat}{noformat}
Regarding your problem you said:
Based on TEM_GT and TXN gt, populating data into EVENT table. Now when I try to populate data in the EVENT_LOW table, the above query returns 5 rows instead of 3 rows.
The above query cannot return 5 rows with the data you have posted. You have 3 rows in TEM_GT and 2 rows in EVENT table. The table are joined ontg.trans_id = e.trans_id AND e.flag = 'N'
And the result of the query with your posted data is *3 rows*. So try to be clear.
If your intention is to insert into EVENT_LOW only one row from TEM_GT for the same trans_id then you have to tell us which is the criteria to choose the row between the duplicates (the first by est_id order??).
Also be careful to post valid statements. The statement below is not valid as it is missing the table name after INSERT INTO and there are 2 consecutive FROM keywords:insert into(event_low_id, event_id, est_id, amount)
select event_low_id_s.nextval e.event_id, tg.est_id, tg.amount from
from TEM_GT tg, EVENT e
WHERE
tg.trans_id = e.trans_id
AND e.flag = 'N'
I will make the assumption that you want to select the first row order by est_id during insertion. If this is not what you want, please change the analytic function:INSERT INTO event_low (event_low_id, event_id, est_id, amount)
WITH got_data AS
SELECT e.event_id, tg.est_id, tg.amount
, ROW_NUMBER() OVER(PARTITION BY tg.trans_id ORDER BY tg.est_id) AS rn
FROM tem_gt tg, event e
WHERE tg.trans_id = e.trans_id
AND e.flag = 'N'
SELECT event_low_id_s.NEXTVAL
, event_id, est_id, amount
FROM got_data
WHERE rn = 1;
If this is not what you want please post CREATE TABLE and INSERT statement, and post your expected output (for insertion into EVENT_LOW table) for the data you have posted.
Regards.
Al

Call the Function against a select query in 500 procedures...

Hello Gurus,
I have a scenario, where i had made one function(UDF Function) to calculate something and in every procedure i call that function and calculate my requirement.
Yesterday, i made a select query using reg exp for the same calculation..
So my question is, what should be the proper approach..
I need to implement this on 500 procedures...
And the UDF function is
CREATE OR REPLACE FUNCTION "UDF_TEXTSPLIT" (
p_list VARCHAR2,
p_del VARCHAR2 := ','
) RETURN split_tbl pipelined
IS
l_idx PLS_INTEGER;
l_list VARCHAR2(7999) ;
l_value VARCHAR2(7999);
BEGIN
l_list := p_list;
LOOP
l_idx := INSTR(l_list,p_del);
IF l_idx > 0 THEN
pipe ROW(SUBSTR(l_list,1,l_idx-1));
l_list := SUBSTR(l_list,l_idx+LENGTH(p_del));
ELSE
pipe ROW(l_list);
EXIT;
END IF;
END LOOP;
RETURN;
END Udf_Textsplit;
I have made this query:
SELECT a.b,z. b1 FROM
(SELECT ROWNUM d,REGEXP_SUBSTR(str1, '[^> ]+', 1, LEVEL) b
FROM (SELECT 'xxx>zzz>gg' str1 FROM dual)
CONNECT BY REGEXP_SUBSTR(str1, '[^> ]+', 1, LEVEL) IS NOT NULL)a,
(SELECT ROWNUM d,REGEXP_SUBSTR(str1, '[^> ]+', 1, LEVEL) b1
FROM (SELECT '100>500>20' str1 FROM dual)
CONNECT BY REGEXP_SUBSTR(str1, '[^> ]+', 1, LEVEL) IS NOT NULL)z
WHERE a.d=z.d
Do i use the same select query in all 500 procedures or call the (UDF Function) in every procedure..
So which will be faster...
Your approach would be very much appreciated...
Thanks,
Haraprasad...

Hmm, do I edit 500 procedures to replace a function call with a SQL statement, or edit 1 function to use a sql statement instead of the current algorithm?
This is why we use code modules that do one thing and do it well. As long as the new version of the function takes the same arguments and returns the same results as the old, then the callers will never know that the way the function works has changed.
Whenther you put the select statement in 500 procedures, or 1 function, there will still be a context switch every time you use it. The tiny additional overhead of calling a function before the context switch would be unnoticeable.
John

Runtime error(Time limit exceeds)after executing select query

Dear experts, whenever i executing the select query in this zprogram i am getting runtime error that time limit exceeds.i am using inner join and into table.after that also i am geetting error. how can i resolve it??
SELECT LIKP~VBELN LIKP~WADAT_IST LIKP~VEHICLE_NO LIKP~TRNAME
          LIKP~VEHI_TYPE LIKP~LR_NO LIKP~ANZPK LIKP~W_BILL_NO
          LIKP~SEALNO1                                       " Seal NO1
          LIKP~SEALNO2                                       " Seal NO2
          LIPS~LFIMG
          VBRP~VBELN VBRP~VGBEL VBRP~MATNR VBRP~AUBEL VBRP~FKIMG
          VBAK~AUART
          VBRK~FKART VBRK~KNUMV VBRK~FKSTO
          FROM LIKP INNER JOIN LIPS ON LIKP~VBELN EQ LIPS~VBELN
                    INNER JOIN VBRP ON LIKP~VBELN EQ VBRP~VGBEL
                    INNER JOIN VBAK ON VBRP~AUBEL EQ VBAK~VBELN
                    INNER JOIN VBRK ON VBRP~VBELN EQ VBRK~VBELN
          INTO TABLE I_FINAL_TEMP
          WHERE LIKP~VSTEL = '5100' AND
             LIKP~WADAT_IST IN S_WADAT AND
                VBRP~AUBEL IN S_AUBEL AND
                VBAK~AUART IN ('ZJOB','ZOR') AND
                VBRK~FKART IN S_FKART AND
*               VBRK~FKART IN ('ZF8','ZF2','ZS1') AND
                VBRK~FKSTO NE 'X'.
When I am debugging the select query.the cursor will not go to next step.after 15-20 minutes i am getting runtime error(time limit exceeds).
how can i resolve it for that scenario??

Looks like whole SD flow you trying to fetch in single query
First you check the database statistic of these table are upto date in system ( Check with basis team )
if this query was working fine earlier.
Most of table involved are huge volume tables which queried with any primary key
Any secondary index on created for LIKP on VSTEL WADET ?
My suggestion would be split the selection queries and make use of primary or existing secondary index to fetch the desired result if possible. For testing purpose split the queries and find which is taking more time and which needs index by taking squel trace in ST05.
Also take ST05 trace of this query in debugger ( New debugger -> special tool -> trace > ST05/SE30)

Select Query Scenario

Similar Messages

Maybe you are looking for