Benchmarks on select statements

Hi,
I'm during preparing test on select statement to check what clause cause the most slow down. Therefore I prepare 3 select statement:
1) select which transform all columns in source table for oracle's functions like: substr, rpad, decode, nvl,upper, mod, greatest, length, power, instr etc..
2) select with big where clause (about 7 lines) which take from 2 tables
3) select which have where, group by, having and order by clauses
Perhaps I will have first result today. But I am very interested what is your experience in this subject?? Which case cause the biggest slow down?
Best.

Hi Tut,
what is your experience in this subject?? Every database is different, but in general:
1) select which transform all columns in source table for oracle's functions like: substr, rpad, decode, nvl,upper, mod, greatest, length, power, instr etc..Very low overhead.
2) select with big where clause (about 7 lines) which take from 2 tablesLong time to parse, and sometime Oracle does not get the cardinality right and joins the tables in the wrong order. To fix this issue:
1 - apply histograms. I have my notes here: http://www.dba-oracle.com/art_otn_cbo_p4.htm
2 - Use an ORDERED hint to enforce the best table join order: I have my notes here: http://www.dba-oracle.com/t_table_join_order.htm
3) select which have where, group by, having and order by clausesJust make sure that you have a large enough PGA to void sorts to disk (sort_area_size, pga_aggregate_target)
Hope this answers your questions . . .
Donald K. Burleson
Oracle Press author
Author of "Oracle Tuning: The Definitive Reference":
http://www.dba-oracle.com/bp/s_oracle_tuning_book.htm

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Need to Improve pefromance for select statement using MSEG table

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

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

If statement in select statement alias

I have the following select statement. It has the alias Survivors, Deaths and "All Cases". Is it posible to use :P_LANGUAGE variable to say that -- IF :P_LANGUAGE = FRENCH THEN alias are Survivants for survivors, Décès for Deaths, Tous_les_cas for All Cases. Please advise
SELECT ALL T_NTR_MULTIBAR.CAT, T_NTR_MULTIBAR.NUM_CASES_LEFTBAR AS Survivors,
T_NTR_MULTIBAR.NUM_CASES_MIDDLEBAR AS Deaths, T_NTR_MULTIBAR.NUM_CASES_RIGHTBAR AS "All Cases"
FROM T_NTR_MULTIBAR
WHERE INSTANCE_NUM = :P_INSTANCENUM
order by ORDERS

You may not be able to add this condition inside the SQL Statement. But you can add this condition outside the statement, if you're using PL/SQL...
IF :p_language = french THEN
SELECT ALL t_ntr_multibar.cat,
t_ntr_multibar.num_cases_leftbar AS survivors,
t_ntr_multibar.num_cases_middlebar AS deaths,
t_ntr_multibar.num_cases_rightbar AS "All Cases"
ELSE
END IF;

How to get all values from an interval using select statement

Hi,
Is it possible to write a select statement that returns all values from an interval? Interval boundaries are variable.
something like this:
select (for x in 1,1024 loop x end loop) from dual
(this, of course, doesn't work)
The result in this example should be 1024 rows of numbers from 1 to 1024. These numbers are parameters, so it is not possible to create a table with predefined values.
Thanks in advance for your help,
Mia.

For your simple case, with a lower boundary of 1, you can use:
SELECT rownum
FROM all_objects
WHERE rownum <= 1024For a set of number between say 50 - 100, you can use something like:
SELECT rownum + (50 - 1)
FROM all_objects
WHERE rownum <= (100 - 50 + 1)Note, that all_objects was used only because it generally has a lot of rows. Any table with at least the number of rows in your range will work.
TTFN
John

Select statement operators in ecc 6.

Hi Experts,
I have a small doubt about the '>=' ( greater than or equal to ) operator usage in select statement. Is this operator by any chance perform not as desired in ECC 6.0. Is it a good option to use 'GE' instead of '>='. ?
It may sound a bit awkward, but still I would like to know. I am facing a situation, which could be related to this. An early response would be highly appreciated.
I would request,you NOT TO REPLY with links/explanations which says how to use select statement. Only answer if you have the answers related to this query.
Regards,
Sandipan

>
Jaideep Sharma wrote:
> Hi,
> The only difference is GE will take a little more time than >= as system need to convert the keyword into actual operator when fetching data from Database.
>
> KR Jaideep,
????? Every Open SQL statements is translated to the SQL slang the underlying database is talking regardless if you type GE or >=
If the result differs using >= or GE i would open a call at SAP instead of asking in SDN.

How to find the number of fetched lines from select statement

Hi Experts,
Can you tell me how to find the number of fetched lines from select statements..
and one more thing is can you tell me how to check the written select statement or written statement is correct or not????
Thanks in advance
santosh

Hi,
Look for the system field SY_TABIX. That will contain the number of records which have been put into an internal table through a select statement.
For ex:
data: itab type mara occurs 0 with header line.
Select * from mara into table itab.
Write: Sy-tabix.
This will give you the number of entries that has been selected.
I am not sure what you mean by the second question. If you can let me know what you need then we might have a solution.
Hope this helps,
Sudhi
Message was edited by:
Sudhindra Chandrashekar

Use of LIKE in where clause of select statement for multiple records

Hi Experts,
I have a account number field which is uploaded from a file. Now this account numbers uploaded does not match fully with sap table account numbers but it contains all of the numbers provided in the file mostly in the upright positions.
For example in file we have account number as 2ARS1 while in sap table the value is 002ARS1.
And i want to fetch data from sap table based on account number uploaded. So, i am trying to use LIKE with for all entries but its not working as mentioned below but LIKE is not working with FOR ALL ENTRIES.
data : begin of t_dda occurs 0,
        dda(19) type c,
       end of t_dda.
data : begin of t_bukrs occurs 0,
        bukrs type t012k-bukrs,
       end of t_bukrs.
data : dda type t012k-bankn,
       w_dda type t012k-bankn.
CONCATENATE '%'
                         '2ARS1'
                 INTO W_DDA.
MOVE W_DDA TO T_DDA-DDA.
APPEND T_DDA.
CLEAR T_DDA.
free t_bukrs.
SELECT BUKRS
FROM T012K
into TABLE t_bukrs
    for all entries in t_dda
WHERE BANKN like t_dda-dda.
Can anybody suggest what should i use to get the data for multiple account numbers using one select statement only instead on using SELECT UP TO 1 ROWS in LOOP....ENDLOOP ?
Thanks in advance,
Akash

Hi,
yes, For All entries won't work for LIKE with '% '.
I think the other alternative is go for Native SQL by writing sub-query
sample code is here:
data: begin of i_mara occurs 0,
          matnr like mara-matnr,
          matkl like mara-matkl,
       end of i_mara.
exec sql.
select matnr, matkl from mara where matnr in (select matnr from marc) and matnr like '%ma' into :i_mara
endexec.
loop at i_mara.
write:/ i_mara-matnr, i_mara-matkl.
endloop.
hope u got it.
regards
Mahesh
Edited by: Mahesh Reddy on Jan 21, 2009 2:32 PM

What is the use of additon in up to 1 rows in SELECT statement

Hi All,
         What is the use of up to 1 rows in select statement.
for example
SELECT kostl
      FROM pa0001
      INTO y_lv_kostl UP TO 1 ROWS
      WHERE pernr EQ pernr
      AND endda GE sy-datum.
    ENDSELECT.
I'm unable to get in wat situations we hav to add up to 1 rows
please help me out...
Thanks,
santosh.

Hi,
Use "select up to 1 rows" only if you are sure that all the records returned will have the same value for the field(s) you are interested in. If not, you will be reading only the first record which matches the criteria, but may be the second or the third record has the value you are looking for.
The System test result showed that the variant Single * takes less time than Up to 1 rows as there is an additional level for COUNT STOP KEY for SELECT ENDSELECT UP TO 1 ROWS.
The 'SELECT .... UP TO 1 ROWS' statement is subtly different. The database selects all of the relevant records that are defined by the WHERE clause, applies any aggregate, ordering or grouping functions to them and then returns the first record of the result set.
Regards,
Bhaskar

Secondary Index Select Statement Problem

Hi friends.
I have a issue with a select statement using secondary index,
SELECT SINGLE * FROM VEKP WHERE VEGR4 EQ STAGE_DOCK
                                  AND VEGR5 NE SPACE
                                  AND WERKS EQ PLANT
        %_HINTS ORACLE
        'INDEX("&TABLE&" "VEKP~Z3" "VEKP^Z3" "VEKP_____Z3")'.
given above statement is taking long time for processing.
when i check for the same secondary index in vekp table i couldn't see any DB index name with vekp~z3 or vekp^z3 or vekp____z3.
And the sy-subrc value after select statement is 4. (even though values avaliable in VEKP with given where condition values)
My question is why my select statement is taking long time and sy-subrc is 4?
what happens if a secnodary index given in select statement, which is not avaliable in that DB Table?

Hi,
> ONe more question: is it possible to give more than one index name in select statement.
yes you can:
read the documentation:
http://download.oracle.com/docs/cd/A97630_01/server.920/a96533/hintsref.htm#5156
index_hint:
This hint can optionally specify one or more indexes:
- If this hint specifies a single available index, then the optimizer performs
a scan on this index. The optimizer does not consider a full table scan or
a scan on another index on the table.
- If this hint specifies a list of available indexes, then the optimizer
considers the cost of a scan on each index in the list and then performs
the index scan with the lowest cost. The optimizer can also choose to
scan multiple indexes from this list and merge the results, if such an
access path has the lowest cost. The optimizer does not consider a full
table scan or a scan on an index not listed in the hint.
- If this hint specifies no indexes, then the optimizer considers the
cost of a scan on each available index on the table and then performs
the index scan with the lowest cost. The optimizer can also choose to
scan multiple indexes and merge the results, if such an access path
has the lowest cost. The optimizer does not consider a full table scan.
Kind regards,
Hermann

BI Publisher : SELECT statement in RTF template

Hi Guys
I have written a BI Publisher Report using XML file created from Oracle Reports(in Oracle Apps).
Repors runs from Oracle Apps perfectly ok. Now I need to fetch some data from couple of tables and display on the Report.
I am wondering whether I can directly code SELECT statement in RTF file rather than messing with Oracle Report(.rdf) file.
Please advise.
Thanks and Regards
Vijay

Hey Vijay,
You cannot query in RTF using select :)..
You have to mess/play with RDF to do it ;)
Oh wait, did i say , we cannot in RTF, we can , but that is difficult approach to go with., keep this as an end of the world option.

Can we use is null in our select statement in ABAP program

hi,
I want to use 'is nul' or 'not null' in select statement of my ABAP program for any field. I have written below query but I am getting sy-subrc = 4 and getting no data. Can anyone resolve this.

Hi,
I think you've posted your question on the wrong forum. This is the SAP Business One development forum which is not part of ERP and doesn't include any ABAP or Netweaver programming.
For a list of forums please see here:
http://forums.sdn.sap.com/index.jspa
Kind Regards,
Owen

Performance issue - Select statement

Hi I am having the 10 lack records in the KONP table . If i am trying to see all the records in SE11 , it is giving the short dump TSV_TNEW_PAGE_ALLOC_FAILED . I know this is because of less memory in the Server . Is there any other way to get the data ? How to optimise the below SELECT statement if i have large data in the table .
i_condn_data - is having 8 lack records .
SELECT knumh kznep valtg valdt zterm
        FROM konp
        INTO TABLE i_condn_data_b
        FOR ALL ENTRIES IN i_condn_data
        WHERE knumh = i_condn_data-knumh
        AND kschl = p_kschl.
Please suggest .

Hi,
try to use "UP TO n ROWS" to control the quantity of selected data in each Loop step.
Something like this:
sort itab by itab-knumh.
flag = 'X'.
while flag = 'X'.
SELECT knumh kznep valtg valdt zterm
FROM konp
INTO TABLE i_condn_data_b UP TO one_million ROWS
WHERE knumh > new_value_for_selection
AND kschl = p_kschl.
describe table i_condn_data_b lines i.
read table i_condn_data_b index i.
new_value_for_selection = i_condn_data_b-knumh.
*....your logic for table i_condn_data_b
if one_million > i.
clear flag.
endif.
endwhile.
Regards

Retrieving multiple values from one column in SELECT statement

Hi,
I have a slight dilemma in that I'm trying to pull down all the values from a column from a select statement that includes some JOINS in it.
If I run the query at the SQL Plus prompt, it pulls back all the values/rows.
When I run the select (and prepared ) statement in my JSP, it only pulls back one of the 4 values I'm trying to retrieve.
e.g.
at the DB level :
SELECT role_name, CC_ID FROM votetbl a
INNER JOIN APPROVERS b ON
a.BUSVP = b.BUSVP AND
a.BRANCH = b.BRANCH
WHERE CC_ID = 1688this will return:
ROLE_NAME CC_ID
ops 1688
ops 1688
comply 1688
legal 1688
comply 1688
When run in my JSP, like so:
String primID3a = request.getParameter("primID");
Statement stmtovoter = connection.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_READ_ONLY);
String prepvotSQL = "SELECT role_name, CC_ID FROM votetbl a INNER JOIN APPROVERS b ON a.BUSVP = b.BUSVP AND " +
"a.BRANCH = b.BRANCH WHERE CC_ID = ?";
PreparedStatement prepvotstmt = connection.prepareStatement(prepvotSQL);
prepvotstmt.setString(1, primID3a);
ResultSet rest3 = prepvotstmt.executeQuery();
rest3.next();
String votecat = rest3.getString(1);
out.println("Vote category: "+votecat);I only get ops returned.
Do I need to run an enumerator? Or reqest.getParameterValues or use a while statement around the results set?
Any feedback and direction here is welcomed!
Thanks!

Actually, I tried looping and still only get 1, but returned several times.
i.e.
PreparedStatement prepvotstmt = connection.prepareStatement(prepvotSQL);
prepvotstmt.setString(1, primID3a);
ResultSet rest3 = prepvotstmt.executeQuery();
rest3.next();
String votecat = rest3.getString(1);
while (rest3.next()) {
out.print("category roles "+votecat);
}then I get returned the following:
admincategory roles admincategory roles admincategory roles admincategory roles admincategory roles admincategory roles admincategory roles admincategory roles admincategory roles admincategory roles admincategory roles admin
like so.
Where as at the DB level I get
ROLE_NAME CC_ID
admin 1688
ops 1688
ops 1688
ops 1688
ops 1688
ops 1688
ops 1688
ops 1688
risk 1688
comply 1688
legal 1688
legal 1688
ops 1688
comply 1688
Maybe the while should go around the getString(1) designation? But I was thinking I'd tried that and gotten invalid cursor error
Something is definitely amiss, between the prepared statement in the servlet and the SELECT statement at the DB level.
I can totally hardcode the statement in the servlet or JSP and it will return one value potentially several times, but only one.
Other times, it will not return a value at all, even though one resides in the db.
Yet go to the DB/SQL Plus prompt and it returns perfectly. I can simply copy and paste the SELECT statement from the out.print line I made and it works like a champ in SQL Plus. Any ideas why the same exact thing cannot return the proper values within the servlet/JSP?
Yeeeeeeesh!!! : (
Message was edited by:
bpropes20

Select statement with LIMIT

I m trying to find if LIMIT is a part of the select statement and if works like
set rowcount 1 in sybase....if anyone can post the generic select statement with LIMIT in it that would be great!
any help or input will be greatly appreciated
Thanks!

Hallo,
i don't know sybase, but it is probably rownum
select * from scott.emp
where rownum < 3
Regards
Dmytro

Reg select statement

hi i have a problem.
i want to extract records from three fields in a table using select statement.after extraction.
if there is no records in the three fields i had to give another condition.can any body provide code for this

HI,
try with this
select field1 field1 field 1
          from <tablename>
          into itab1
          where
          condition1...
now u check for
if sy-subrc ne 0. OR itab1[] is initial.
select field1 field1 field 1
          from <tablename>
          into itab1
          where
          condition1...
          condition2...
endif.
If i am not clear ... reply back
Santhosh

Benchmarks on select statements

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