Performance tuning of a function which is part of a package.

Hello
I just built a function in a package. And now I want to make sure that the SQL is well tuned.
I was going through the links mentioned in this post
Performance Tuning
to know more about performance tuning.
But I am confused with some simple things.
So when we analyze a single function present in a package , should I use the SQL of the function or
should I use a call to that function.
For example first I thought of using EXPLAIN PLAN.
I see a different explain plan when I use a call to that function then
when I use the actual SQL of the function with some plugged in parameters whereever required.
What is the right way of doing it?
Thank you

I recommend :
1. use SQL tracing with DBMS_MONITOR and then TKPROF on raw SQL trace file
2. call the function as it used in your production environment
See good examples in http://www.oracle-base.com/articles/10g/SQLTrace10046TrcsessAndTkprof10g.php (just refer to DBMS_MONITOR examples and TKPROF).
Note that SQL trace will only trace SQL and not PL/SQL. If SQL elapsed time does not match function call elapsed time close enough, you need to use DBMS_PROFILER to know where PL/SQL non SQL code elapsed time is used.
I don't recommend using EXPLAIN PLAN because it has known limitations http://docs.oracle.com/cd/E11882_01/server.112/e16638/ex_plan.htm#PFGRF94673 (others have said "EXPLAIN PLAN lies" - you can google for this expression ....).
Edited by: P. Forstmann on 10 févr. 2012 19:44

Similar Messages

Performance Tuning the AVG function

Dear All,
I have a table which is rapidly growing. We have a query which is frequently executed on this table and it utilizes AVG function without a WHERE clause. Is there a way to tune this query?
I tried to create a Materialized View but Oracle rejects as AVG cannot be used in MV's. Also, it is now really easy at this point in time to rewrite the query.
Appreciate if anybody can help me out in this situation.
OS: Windows 2003 EE
Database: Oracle 10g R2 10.2.0.4
Sample Table:
Create table t(id number, name varchar2(30), amt number);
insert into t select level, 'level - ' || level, level * 100 from dual connect by dual level <= 1000;
commit;
Query:
select avg(amount) from t;
Thanks for you time.
- P

>
... and it utilizes AVG function without a WHERE clause
>
As Aman stated, a full table scan will be needed for a statement without a WHERE clause.
See these threads on how to post a tuning request
When your query takes too long ...
HOW TO: Post a SQL statement tuning request - template posting
HTH
Srini

Oracle Database 11g: Performance Tuning-Certification

Dear All!
I want to take exam 1z0-054 for
"Oracle Database 11g: Performance Tuning".
I've completed an Oracle authorized couse of "Oracle Database 11g: Performance Tuning DBA" in 2008,which is one of requirements to get that certificate.
Please any info regarding to expiration of complilation of courses?
If I pass 1z0-054 exam ,will the above mentioned couse considered?
And the last one, Are there possibilities to see or load the info of the couses I've completed , to my Oracle site acount.
Thanks in advance!
Best regards

Try posting this type of question in the Certification forum:
Oracle Certification Program

Need help in Performance tuning for function...

Hi all,
I am using the below algorithm for calculating the Luhn Alogorithm to calculate the 15th luhn digit for an IMEI (Phone Sim Card).
But the below function is taking about 6 min for 5 million records. I had 170 million records in a table want to calculate the luhn digit for all of them which might take up to 4-5 hours.Please help me performance tuning (better way or better logic for luhn calculation) to the below function.
A wikipedia link is provided for the luhn algorithm below
Create or Replace FUNCTION AddLuhnToIMEI (LuhnPrimitive VARCHAR2)
 RETURN VARCHAR2
 AS
 Index_no NUMBER (2) := LENGTH (LuhnPrimitive);
 Multiplier NUMBER (1) := 2;
 Total_Sum NUMBER (4) := 0;
 Plus NUMBER (2);
 ReturnLuhn VARCHAR2 (25);
 BEGIN
 WHILE Index_no >= 1
 LOOP
 Plus := Multiplier * (TO_NUMBER (SUBSTR (LuhnPrimitive, Index_no, 1)));
 Multiplier := (3 - Multiplier);
 Total_Sum := Total_Sum + TO_NUMBER (TRUNC ( (Plus / 10))) + MOD (Plus, 10);
 Index_no := Index_no - 1;
 END LOOP;
 ReturnLuhn := LuhnPrimitive || CASE
 WHEN MOD (Total_Sum, 10) = 0 THEN '0'
 ELSE TO_CHAR (10 - MOD (Total_Sum, 10))
 END;
 RETURN ReturnLuhn;
 EXCEPTION
 WHEN OTHERS
 THEN
 RETURN (LuhnPrimitive);
 END AddLuhnToIMEI;
http://en.wikipedia.org/wiki/Luhn_algorithmAny sort of help is much appreciated....
Thanks
Rede

There is a not needed to_number function in it. TRUNC will already return a number.
Also the MOD function can be avoided at some steps. Since multiplying by 2 will never be higher then 18 you can speed up the calculation with this.
create or replace
FUNCTION AddLuhnToIMEI_fast (LuhnPrimitive VARCHAR2)
 RETURN VARCHAR2
 AS
 Index_no pls_Integer;
 Multiplier pls_Integer := 2;
 Total_Sum pls_Integer := 0;
 Plus pls_Integer;
 rest pls_integer;
 ReturnLuhn VARCHAR2 (25);
 BEGIN
 for Index_no in reverse 1..LENGTH (LuhnPrimitive) LOOP
 Plus := Multiplier * TO_NUMBER (SUBSTR (LuhnPrimitive, Index_no, 1));
 Multiplier := 3 - Multiplier;
 if Plus < 10 then
 Total_Sum := Total_Sum + Plus ;
 else
 Total_Sum := Total_Sum + Plus - 9;
 end if;
 END LOOP;
 rest := MOD (Total_Sum, 10);
 ReturnLuhn := LuhnPrimitive || CASE WHEN rest = 0 THEN '0' ELSE TO_CHAR (10 - rest) END;
 RETURN ReturnLuhn;
 END AddLuhnToIMEI_fast;
/My tests gave an improvement for about 40%.
The next step to try could be to use native complilation on this function. This can give an additional big boost.
Edited by: Sven W. on Mar 9, 2011 8:11 PM

Performance tuning of a customised Transaction Code which for interface

Hii All ,
I am new to performance tuning please guide me How to do performance tuning of Custom T-code through I am aware of all T-codes for performance tuning.
Please guide hoe to do it and what are basic need to before to start Performance tuning ?
Thanks
ABAP Pro
Moderator message: Please Read before Posting in the Performance and Tuning Forum
Locked by: Thomas Zloch on Jun 7, 2011 9:37 AM

I recommend :
1. use SQL tracing with DBMS_MONITOR and then TKPROF on raw SQL trace file
2. call the function as it used in your production environment
See good examples in http://www.oracle-base.com/articles/10g/SQLTrace10046TrcsessAndTkprof10g.php (just refer to DBMS_MONITOR examples and TKPROF).
Note that SQL trace will only trace SQL and not PL/SQL. If SQL elapsed time does not match function call elapsed time close enough, you need to use DBMS_PROFILER to know where PL/SQL non SQL code elapsed time is used.
I don't recommend using EXPLAIN PLAN because it has known limitations http://docs.oracle.com/cd/E11882_01/server.112/e16638/ex_plan.htm#PFGRF94673 (others have said "EXPLAIN PLAN lies" - you can google for this expression ....).
Edited by: P. Forstmann on 10 févr. 2012 19:44

Which tool is used for Oracle 11g performance tuning?

Hi all
I used statspack for 9i's performance tuning.
But with 11g R2 now I want to know which way are you using to do performance tuning?
Statspack? OSW? RDA? ADDM? Or other ways?
Thank you.

schavali wrote:
I would start with Automatic Workload Repository (AWR) reports to identify the bottleneck
MOS Doc 390374.1 - Oracle Performance Diagnostic Guide (OPDG)
MOS Doc 748642.1 - What is AWR( Automatic workload repository ) and How to generate the AWR report?
HTH
SriniThanks for your answer.
To read the MOS documents I need a Oracle Customer ID , is that right ?
(Where to get that ID ? Our company bought Oracle 10g without any Customer IDs in it )
Best Wishes.

Reg: Process Chain, query performance tuning steps

Hi All,
I come across a question like, There is a process chain of 20 processes.out of which 5 processes are completed at the 6th step error occured and it cannot be rectified. I should start the chain again from the 7th step.If i go to a prticular step i can do that particular step, How can i start the entair chain again from step 7.i know that i need to use a function module but i dont know the name of FM. Please somebody help me out.
Please let me know the steps involved in query performance tuning and aggregate tuning.
Thanks & Regards
Omkar.K

Hi,
Process Chain
Method 1 (when it fails in a step/request)
/people/siegfried.szameitat/blog/2006/02/26/restarting-processchains
How is it possible to restart a process chain at a failed step/request?
Sometimes, it doesn't help to just set a request to green status in order to run the process chain from that step on to the end.
You need to set the failed request/step to green in the database as well as you need to raise the event that will force the process chain to run to the end from the next request/step on.
Therefore you need to open the messages of a failed step by right clicking on it and selecting 'display messages'.
In the opened popup click on the tab 'Chain'.
In a parallel session goto transaction se16 for table rspcprocesslog and display the entries with the following selections:
1. copy the variant from the popup to the variante of table rspcprocesslog
2. copy the instance from the popup to the instance of table rspcprocesslog
3. copy the start date from the popup to the batchdate of table rspcprocesslog
Press F8 to display the entries of table rspcprocesslog.
Now open another session and goto transaction se37. Enter RSPC_PROCESS_FINISH as the name of the function module and run the fm in test mode.
Now copy the entries of table rspcprocesslog to the input parameters of the function module like described as follows:
1. rspcprocesslog-log_id -> i_logid
2. rspcprocesslog-type -> i_type
3. rspcprocesslog-variante -> i_variant
4. rspcprocesslog-instance -> i_instance
5. enter 'G' for parameter i_state (sets the status to green).
Now press F8 to run the fm.
Now the actual process will be set to green and the following process in the chain will be started and the chain can run to the end.
Of course you can also set the state of a specific step in the chain to any other possible value like 'R' = ended with errors, 'F' = finished, 'X' = cancelled ....
Check out the value help on field rspcprocesslog-state in transaction se16 for the possible values.
Query performance tuning
General tips
Using aggregates and compression.
Using less and complex cell definitions if possible.
1. Avoid using too many nav. attr
2. Avoid RKF and CKF
3. Many chars in row.
By using T-codes ST03 or ST03N
Go to transaction ST03 > switch to expert mode > from left side menu > and there in system load history and distribution for a particual day > check query execution time.
/people/andreas.vogel/blog/2007/04/08/statistical-records-part-4-how-to-read-st03n-datasets-from-db-in-nw2004
/people/andreas.vogel/blog/2007/03/16/how-to-read-st03n-datasets-from-db
Try table rsddstats to get the statistics
Using cache memoery will decrease the loading time of the report.
Run reporting agent at night and sending results to email.This will ensure use of OLAP cache. So later report execution will retrieve the result faster from the OLAP cache.
Also try
1. Use different parameters in ST03 to see the two important parameters aggregation ratio and records transferred to F/E to DB selected.
2. Use the program SAP_INFOCUBE_DESIGNS (Performance of BW infocubes) to see the aggregation ratio for the cube. If the cube does not appear in the list of this report, try to run RSRV checks on the cube and aggregates.
Go to SE38 > Run the program SAP_INFOCUBE_DESIGNS
It will shown dimension Vs Fact tables Size in percent.If you mean speed of queries on a cube as performance metric of cube,measure query runtime.
3. --- sign is the valuation of the aggregate. You can say -3 is the valuation of the aggregate design and usage. ++ means that its compression is good and access is also more (in effect, performance is good). If you check its compression ratio, it must be good. -- means the compression ratio is not so good and access is also not so good (performance is not so good).The more is the positives...more is useful the aggregate and more it satisfies the number of queries. The greater the number of minus signs, the worse the evaluation of the aggregate. The larger the number of plus signs, the better the evaluation of the aggregate.
if "-----" then it means it just an overhead. Aggregate can potentially be deleted and "+++++" means Aggregate is potentially very useful.
Refer.
http://help.sap.com/saphelp_nw70/helpdata/en/b8/23813b310c4a0ee10000000a114084/content.htm
http://help.sap.com/saphelp_nw70/helpdata/en/60/f0fb411e255f24e10000000a1550b0/frameset.htm
4. Run your query in RSRT and run the query in the debug mode. Select "Display Aggregates Found" and "Do not use cache" in the debug mode. This will tell you if it hit any aggregates while running. If it does not show any aggregates, you might want to redesign your aggregates for the query.
Also your query performance can depend upon criteria and since you have given selection only on one infoprovider...just check if you are selecting huge amount of data in the report
Check for the query read mode in RSRT.(whether its A,X or H)..advisable read mode is X.
5. In BI 7 statistics need to be activated for ST03 and BI admin cockpit to work.
By implementing BW Statistics Business Content - you need to install, feed data and through ready made reports which for analysis.
http://help.sap.com/saphelp_nw70/helpdata/en/26/4bc0417951d117e10000000a155106/frameset.htm
/people/vikash.agrawal/blog/2006/04/17/query-performance-150-is-aggregates-the-way-out-for-me
https://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/docs/library/uuid/1955ba90-0201-0010-d3aa-8b2a4ef6bbb2
https://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/docs/library/uuid/ce7fb368-0601-0010-64ba-fadc985a1f94
http://help.sap.com/saphelp_nw04/helpdata/en/c1/0dbf65e04311d286d6006008b32e84/frameset.htm
You can go to T-Code DB20 which gives you all the performance related information like
Partitions
Databases
Schemas
Buffer Pools
Tablespaces etc
use tool RSDDK_CHECK_AGGREGATE in se38 to check for the corrupt aggregates
If aggregates contain incorrect data, you must regenerate them.
Note 646402 - Programs for checking aggregates (as of BW 3.0B SP15)
Thanks,
JituK

Performance Tuning - Suggestions

Hi,
I have an ABAP (Interactive List) Program times out in PRD very often. The ABAP run time is about 99%. The DB time is less than 1%. All the select statements has the table index in place. Actually it isprocessing all the Production Orders (Released but not Confirmed/Closed). Please let me know if you have any suggestion.
Appreciate Your Help.
Thanks,
Kannan.

Hi
1) Dont use nested select statements
2) If possible use for all entries in addition
3) In the where addition make sure you give all the primary key
4) Use Index for the selection criteria.
5) You can also use inner joins
6) You can try to put the data from the first select statement into an Itab and then in order to select the data from the second table use for all entries in.
7) Use the runtime analysis SE30 and SQL Trace (ST05) to identify the performance and also to identify where the load is heavy, so that you can change the code accordingly
https://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/docs/library/uuid/5d0db4c9-0e01-0010-b68f-9b1408d5f234
ABAP performance depends upon various factors and in devicded in three parts:
1. Database
2. ABAP
3. System
Run Any program using SE30 (performance analys) to improve performance refer to tips and trics section of SE30, Always remember that ABAP perfirmance is improved when there is least load on Database.
u can get an interactive grap in SE30 regarding this with a file.
also if u find runtime of parts of codes then use :
Switch on RTA Dynamically within ABAP Code
*To turn runtim analysis on within ABAP code insert the following code
SET RUN TIME ANALYZER ON.
*To turn runtim analysis off within ABAP code insert the following code
SET RUN TIME ANALYZER OFF.
Always check the driver internal tables is not empty, while using FOR ALL ENTRIES
Avoid for all entries in JOINS
Try to avoid joins and use FOR ALL ENTRIES.
Try to restrict the joins to 1 level only ie only for tables
Avoid using Select *.
Avoid having multiple Selects from the same table in the same object.
Try to minimize the number of variables to save memory.
The sequence of fields in 'where clause' must be as per primary/secondary index ( if any)
Avoid creation of index as far as possible
Avoid operators like <>, > , < & like % in where clause conditions
Avoid select/select single statements in loops.
Try to use 'binary search' in READ internal table. Ensure table is sorted before using BINARY SEARCH.
Avoid using aggregate functions (SUM, MAX etc) in selects ( GROUP BY , HAVING,)
Avoid using ORDER BY in selects
Avoid Nested Selects
Avoid Nested Loops of Internal Tables
Try to use FIELD SYMBOLS.
Try to avoid into Corresponding Fields of
Avoid using Select Distinct, Use DELETE ADJACENT
Check the following Links
Re: performance tuning
Re: Performance tuning of program
http://www.sapgenie.com/abap/performance.htm
http://www.thespot4sap.com/Articles/SAPABAPPerformanceTuning_PerformanceAnalysisTools.asp
check the below link
http://www.sap-img.com/abap/performance-tuning-for-data-selection-statement.htm
See the following link if it's any help:
http://www.thespot4sap.com/Articles/SAPABAPPerformanceTuning_PerformanceAnalysisTools.asp
Check also http://service.sap.com/performance
and
books like
http://www.sap-press.com/product.cfm?account=&product=H951
http://www.sap-press.com/product.cfm?account=&product=H973
http://www.sap-img.com/abap/more-than-100-abap-interview-faqs.htm
http://www.thespot4sap.com/Articles/SAPABAPPerformanceTuning_PerformanceAnalysisTools.asp
Performance tuning for Data Selection Statement
http://www.sap-img.com/abap/performance-tuning-for-data-selection-statement.htm
Debugger
http://help.sap.com/saphelp_47x200/helpdata/en/c6/617ca9e68c11d2b2ab080009b43351/content.htm
http://www.cba.nau.edu/haney-j/CIS497/Assignments/Debugging.doc
http://help.sap.com/saphelp_erp2005/helpdata/en/b3/d322540c3beb4ba53795784eebb680/frameset.htm
Run Time Analyser
http://help.sap.com/saphelp_47x200/helpdata/en/c6/617cafe68c11d2b2ab080009b43351/content.htm
SQL trace
http://help.sap.com/saphelp_47x200/helpdata/en/d1/801f7c454211d189710000e8322d00/content.htm
CATT - Computer Aided Testing Too
http://help.sap.com/saphelp_47x200/helpdata/en/b3/410b37233f7c6fe10000009b38f936/frameset.htm
Test Workbench
http://help.sap.com/saphelp_47x200/helpdata/en/a8/157235d0fa8742e10000009b38f889/frameset.htm
Coverage Analyser
http://help.sap.com/saphelp_47x200/helpdata/en/c7/af9a79061a11d4b3d4080009b43351/content.htm
Runtime Monitor
http://help.sap.com/saphelp_47x200/helpdata/en/b5/fa121cc15911d5993d00508b6b8b11/content.htm
Memory Inspector
http://help.sap.com/saphelp_47x200/helpdata/en/a2/e5fc84cc87964cb2c29f584152d74e/content.htm
ECATT - Extended Computer Aided testing tool.
http://help.sap.com/saphelp_47x200/helpdata/en/20/e81c3b84e65e7be10000000a11402f/frameset.htm
Just refer to these links...
performance
Performance
Performance Guide
performance issues...
Performance Tuning
Performance issues
performance tuning
performance tuning
You can go to the transaction SE30 to have the runtime analysis of your program.Also try the transaction SCI , which is SAP Code Inspector.
1 Always check the driver internal tables is not empty, while using FOR ALL ENTRIES
2 Avoid for all entries in JOINS
3 Try to avoid joins and use FOR ALL ENTRIES.
4 Try to restrict the joins to 1 level only ie only for 2 tables
5 Avoid using Select *.
6 Avoid having multiple Selects from the same table in the same object.
7 Try to minimize the number of variables to save memory.
8 The sequence of fields in 'where clause' must be as per primary/secondary index ( if any)
9 Avoid creation of index as far as possible
10 Avoid operators like <>, > , < & like % in where clause conditions
11 Avoid select/select single statements in loops.
12 Try to use 'binary search' in READ internal table. Ensure table is sorted before using BINARY SEARCH.
13 Avoid using aggregate functions (SUM, MAX etc) in selects ( GROUP BY , HAVING,)
14 Avoid using ORDER BY in selects
15 Avoid Nested Selects
16 Avoid Nested Loops of Internal Tables
17 Try to use FIELD SYMBOLS.
18 Try to avoid into Corresponding Fields of
19 Avoid using Select Distinct, Use DELETE ADJACENT.
Regards
Anji

Oracle Query Performance While calling a function in a View

Hi,
We have a performance issue in one of our Oracle queries.
Here is the scenario
We use a hard coded value (which is the maximum value from a table) in couple of DECODE statements in our query. We would like to remove this hard coded value from the query. So we wrote a function which will return a maximum value from the table. Now when we execute the query after replacing the hard coded value with the function, this function is called four times which hampers the query performance.
Pl find below the DECODE statements in the query. This query is part of a main VIEW.
Using Hardcoded values
=================
DECODE(pro_risk_weighted_ctrl_scr, 10, 9.9, pro_risk_weighted_ctrl_scr)
DECODE(pro_risk_score, 46619750, 46619749, pro_risk_score)
Using Functions
============
DECODE (pro_risk_weighted_ctrl_scr, rprowbproc.fn_max_rcsa_range_values ('CSR'), rprowbproc.fn_max_rcsa_range_values('CSR')- 0.1, pro_risk_weighted_ctrl_scr)
DECODE (pro_risk_score, rprowbproc.fn_max_rcsa_range_values ('RSR'), rprowbproc.fn_max_rcsa_range_values ('RSR') - 1, pro_risk_score)
Can any one suggest a way to improve the performance of the query.
Thanks & Regards,
Raji

drop table max_demo;
create table max_demo
(rcsa varchar2(10)
,value number);
insert into max_demo
select case when mod(rownum,2) = 0
 then 'CSR'
 else 'RSR'
 end
, rownum
from dual
connect by rownum <= 10000;
create or replace function f_max (
i_rcsa in max_demo.rcsa%TYPE
return number
as
l_max number;
begin
 select max(value)
 into l_max
 from max_demo
 where rcsa = i_rcsa;
 return l_max;
end;
-- slooooooooooooowwwwww
select m.*
, f_max(rcsa)
, decode(rcsa,'CSR',decode(value,f_max('CSR'),'Y - max is '||f_max('CSR'),'N - max is '||f_max('CSR'))) is_max_csr
, decode(rcsa,'RSR',decode(value,f_max('RSR'),'Y - max is '||f_max('RSR'),'N - max is '||f_max('RSR'))) is_max_rsr
from max_demo m
order by value desc;
-- ssllooooowwwww
with subq_max as
 (select f_max('CSR') max_csr,
 f_max('RSR') max_rsr
 from dual)
select m.*
, decode(rcsa,'CSR',s.max_csr,'RSR',s.max_rsr) max
, decode(rcsa,'CSR',decode(value,s.max_csr,'Y - max is '||s.max_csr,'N - max is '||s.max_csr)) is_max_csr
, decode(rcsa,'RSR',decode(value,s.max_rsr,'Y - max is '||s.max_rsr,'N - max is '||s.max_rsr)) is_max_rsr
from max_demo m
, subq_max s
order by value desc;
-- faster
with subq_max as
 (select /*+materialize */
 f_max('CSR') max_csr,
 f_max('RSR') max_rsr
 from dual)
select m.*
, decode(rcsa,'CSR',s.max_csr,'RSR',s.max_rsr) max
, decode(rcsa,'CSR',decode(value,s.max_csr,'Y - max is '||s.max_csr,'N - max is '||s.max_csr)) is_max_csr
, decode(rcsa,'RSR',decode(value,s.max_rsr,'Y - max is '||s.max_rsr,'N - max is '||s.max_rsr)) is_max_rsr
from max_demo m
, subq_max s
order by value desc;
-- faster
with subq_max as
 (select f_max('CSR') max_csr,
 f_max('RSR') max_rsr,
 rownum
 from dual)
select m.*
, decode(rcsa,'CSR',s.max_csr,'RSR',s.max_rsr) max
, decode(rcsa,'CSR',decode(value,s.max_csr,'Y - max is '||s.max_csr,'N - max is '||s.max_csr)) is_max_csr
, decode(rcsa,'RSR',decode(value,s.max_rsr,'Y - max is '||s.max_rsr,'N - max is '||s.max_rsr)) is_max_rsr
from max_demo m
, subq_max s
order by value desc;
-- sloooooowwwwww
select m.*
, decode(rcsa,'CSR',s.max_csr,'RSR',s.max_rsr) max
, decode(rcsa,'CSR',decode(value,s.max_csr,'Y - max is '||s.max_csr,'N - max is '||s.max_csr)) is_max_csr
, decode(rcsa,'RSR',decode(value,s.max_rsr,'Y - max is '||s.max_rsr,'N - max is '||s.max_rsr)) is_max_rsr
from max_demo m
, (select /*+ materialize */
 f_max('CSR') max_csr,
 f_max('RSR') max_rsr
 from dual) s
order by value desc;
-- faster
select m.*
, decode(rcsa,'CSR',s.max_csr,'RSR',s.max_rsr) max
, decode(rcsa,'CSR',decode(value,s.max_csr,'Y - max is '||s.max_csr,'N - max is '||s.max_csr)) is_max_csr
, decode(rcsa,'RSR',decode(value,s.max_rsr,'Y - max is '||s.max_rsr,'N - max is '||s.max_rsr)) is_max_rsr
from max_demo m
, (select f_max('CSR') max_csr,
 f_max('RSR') max_rsr,
 rownum
 from dual) s
order by value desc;

Oracle Performance Tuning Certification

Hi Guys
I am going for 10g OCP then maybe 11g Tuning Expert Certification.
1. I look at the prerequisites of 10g Performance Tuning course:
Required Prerequisites:
* Knowledge of Database Administration
* Oracle Database 10g: Administration Workshop I Release 2
* Oracle Database 10g: Administration Workshop II
* Oracle Database 10g: New Features for Administrators Release 2
Does this mean that it is COMPULSORY that I take the 3 courses above first before I can take the Performance tuning course? This cost a lot of $$$! ; o
2. Where can I get 11gTuning Expert Certification practice questions? From the 11g Performance Tuning course? Couldn't find it in SelfTestSoftware....
Advance thanks!

user8092567 wrote:
Hi,
Exam # 1Z0-044 does not exist.
Why there is no Oracle exam for Performance Tuning for 10g?
There is one for 9i and there will be one for 11g (currently it is in beta).
Lorrys,
I guess this needs to be corrected a bit. 9i exam is a part of teh OCP track, its not an individual exam which you may clear and would be awarded an certification for it. OCE is itself is an certification track and unlikely OCP, it doesn't need multiple exams to be cleared. You just have to clear one exam and youwould be awarded teh certification. Now, about the 10g exam of PT OCE not being there and given in 11g, it should make sense as 11g is already out and there is no point in launchnig a NEW certification track for a previous version. So that's why 11g PT is launched for the newest release, which is 11g.
That said, I am not from Oracle so its just my own opinion about your comment.
HTH
Aman....

Performance tuning for Sales Order and its configuration data extraction

I write here the data fetching subroutine of an extract report.
This report takes 2.5 hours to extract 36000 records in the quality server.
Kindly provide me some suggestions for performance tuning it.
    SELECT auart vkorg vtweg spart vkbur augru
              kunnr yxinsto bstdk vbeln kvgr1 kvgr2 vdatu
              gwldt audat knumv
              FROM vbak
              INTO TABLE it_vbak
              WHERE vbeln IN s_vbeln
              AND erdat IN s_erdat
              AND auart IN s_auart
              AND vkorg = p_vkorg
              AND spart IN s_spart
              AND vkbur IN s_vkbur
              AND vtweg IN s_vtweg.
IF NOT it_vbak[] IS INITIAL.
    SELECT mvgr1 mvgr2 mvgr3 mvgr4 mvgr5
           yyequnr vbeln cuobj
           FROM vbap
           INTO TABLE it_vbap
           FOR ALL ENTRIES IN it_vbak
           WHERE vbeln = it_vbak-vbeln
           AND   posnr = '000010'.
    SELECT bstkd inco1 zterm vbeln
           prsdt
           FROM vbkd
           INTO TABLE it_vbkd
           FOR ALL ENTRIES IN it_vbak
           WHERE vbeln = it_vbak-vbeln.
    SELECT kbetr kschl knumv
           FROM konv
           INTO TABLE it_konv
           FOR ALL ENTRIES IN it_vbak
           WHERE knumv = it_vbak-knumv
           AND   kschl = 'PN00'.
    SELECT vbeln parvw kunnr
           FROM vbpa
           INTO TABLE it_vbpa
           FOR ALL ENTRIES IN it_vbak
           WHERE vbeln = it_vbak-vbeln
           AND parvw IN ('PE', 'YU', 'RE').
ENDIF.
LOOP AT it_vbap INTO wa_vbap.
    IF NOT wa_vbap-cuobj IS INITIAL.
      CALL FUNCTION 'VC_I_GET_CONFIGURATION'
           EXPORTING
                instance            = wa_vbap-cuobj
                language            = sy-langu
           TABLES
                configuration       = it_config
           EXCEPTIONS
                instance_not_found = 1
                internal_error      = 2
                no_class_allocation = 3
                instance_not_valid = 4
                OTHERS              = 5.
      IF sy-subrc = 0.
        READ TABLE it_config WITH KEY atnam = 'IND_PRODUCT_LINES'.
        IF sy-subrc = 0.
          wa_char-obj = wa_vbap-cuobj.
          wa_char-atnam = it_config-atnam.
          wa_char-atwrt = it_config-atwrt.
          APPEND wa_char TO it_char.
          CLEAR wa_char.
        ENDIF.
        READ TABLE it_config WITH KEY atnam = 'IND_GQ'.
        IF sy-subrc = 0.
          wa_char-obj = wa_vbap-cuobj.
          wa_char-atnam = it_config-atnam.
          wa_char-atwrt = it_config-atwrt.
          APPEND wa_char TO it_char.
          CLEAR wa_char.
        ENDIF.
        READ TABLE it_config WITH KEY atnam = 'IND_VKN'.
        IF sy-subrc = 0.
          wa_char-obj = wa_vbap-cuobj.
          wa_char-atnam = it_config-atnam.
          wa_char-atwrt = it_config-atwrt.
          APPEND wa_char TO it_char.
          CLEAR wa_char.
        ENDIF.
        READ TABLE it_config WITH KEY atnam = 'IND_ZE'.
        IF sy-subrc = 0.
          wa_char-obj = wa_vbap-cuobj.
          wa_char-atnam = it_config-atnam.
          wa_char-atwrt = it_config-atwrt.
          APPEND wa_char TO it_char.
          CLEAR wa_char.
        ENDIF.
        READ TABLE it_config WITH KEY atnam = 'IND_HQ'.
        IF sy-subrc = 0.
          wa_char-obj = wa_vbap-cuobj.
          wa_char-atnam = it_config-atnam.
          wa_char-atwrt = it_config-atwrt.
          APPEND wa_char TO it_char.
          CLEAR wa_char.
        ENDIF.
    READ TABLE it_config WITH KEY atnam = 'IND_CALCULATED_INST_HOURS'.
        IF sy-subrc = 0.
          wa_char-obj = wa_vbap-cuobj.
          wa_char-atnam = it_config-atnam.
          wa_char-atwrt = it_config-atwrt.
          APPEND wa_char TO it_char.
          CLEAR wa_char.
        ENDIF.
      ENDIF.
    ENDIF.
ENDLOOP. " End of loop on it_vbap
Edited by: jaya rangwani on May 11, 2010 12:50 PM
Edited by: jaya rangwani on May 11, 2010 12:52 PM

Hello Jaya,
Will provide some point which will increase the performance of the program:
1.     VBAK & VBAP are header & item table. And so the relation will be 1 to many. In this case, you can use inner join instead multiple select statement.
2.     If you are very much confident in handling the inner join, then you can do a single statement to get the data from VBAK, VBAP & VBKD using the inner join.
3.     Before using for all entries, check whether the internal table is not initial.
And sort the internal table and delete adjacent duplicates.
4.     Sort all the resultant internal table based on the required key fields and read always using the binary search.
You will get a number of documents where you can get a fair idea of what should be done and what should not be while doing a program related to performance issue.
Also you can have number of function module and BAPI where you can get the sales order details. You can try with u2018BAPISDORDER_GETDETAILEDLISTu2019.
Regards,
Selva K.

Performance tuning tools

hi Gurus,
Sorry to disturb u, have a big trouble with performance tuning.
I m working on performance tuning part for a project and i have got the w
they jus give me the whole report about the performance releated isses at all levels so everthing is there(repert is Based on Production ) but now after going through this report wot to do and where to start cos i only got access to Test client and no access to development cleint first things and than the major problem they are facing is that when they run report in a Test cleint performance is ok but when they run reports in a Production then system performance is really poor, so they want to know the reason for that as well.
as far as i understand is that for performance in prod system i should have acces to the system first and thean check the database there,so the thing is that can u plz tell me that how to check the database and how to run whole system report on that system as well which gives me complete report for the whole system performance including OS level, DB level,And than SAP systme level,they have some of this kind of tool here to use that but dont kknow which 1 is that and how to use that.
waiting for reply.
thanks In advance.
regards
Amit

Hi Dash,
thanks for quick reply.
when i go and check the report in ST02 so there Hit Ratio is 99.94%, but query running time is significantly or i should say more than 3 times in Production system, so dont know where the problem is.
Cos i m getting slow performance in a Prod system so dont know that how to start analysis on that systme cos i dont have acess to Prod system, so plz and other
commment on this ll be appriciated.
thanks
regards
Amit

SAP CRM Performance tuning

From where can I get information or documents how to do performance tuning in SAP CRM?

Hi, Performance Tuning a SAP system is unique in every environment, also there are many area's in SAP to tune even area's outside SAP, eg... your Operating System/Network/Client Machines/Virtual Landscape/Cloud.
I recommend that you engage in a performance testing execise which will identify what area of your SAP Landscape needs tuning, first you need to identify the bottleneck before you can tune it.
The way the question was posed is exactly the same as wanting to fix a car but you have no idea which part of the car to fix...
*LoadRunner is an excellent tool to simulate virtual work load on an SAP environment*
Regards
Sodick25
http://www.2createawebsite.co.za
Edited by: Sodick25 on Aug 15, 2011 11:58 AM
Edited by: Sodick25 on Aug 15, 2011 11:59 AM

Business Process Performance Tuning

Hi Pals,
I would like to request your help and inputs regarding tuning performance of Business process for my scenario.
I have created a synchronous Process with 3 message mapping transformation steps. ( inbetween Sync Receive and Sync Send steps). So its pretty simple process.
I am able to execute only 3500 processes per hour.
The SAP Netweaver Server m/c configuration is 2 dual core processors with 12 GB RAM.
Business process - Without buffering with multiple queues (content specific).
IE Logging - No sync logging, logging level - 0 ( so logging turned off )
I have tried out all the configurations mentioned in below weblogs, but with very less improvement in my case.
Performance Tuning Checks in SAP Exchange Infrastructure(XI): Part-III
Performance Tuning Checks in SAP Exchange Infrastructure(XI): Part-II
Performance Tuning Checks in SAP Exchange Infrastructure
I think something else is choking the execution, as the CPU or memory usage is not more than 10-20%.
Please pour in your inputs.
Thank you!
Best Regards,
Saravanan N

Thank you very much Bhavesh!
In my BPM, all the steps are set for "No New Transaction". So as to avoid any performance issue. But there is no improvement.
Even I have deleted all the work-items from Trxn: SWWL before the test.
From ST03N, for each process instance executed, four function modules takes the maximum time.
Function Module--No. of Calls--
Execution Time/RFC Call
TRFC_QIN_DEST_SHIP-- 1--
995 milliseconds
TRFC_QIN_ACTIVATE--1--
1077 milliseconds
ARFC_DEST_SHIP--2--
280 milliseconds
ARFC_RUN_NOWAIT--2--
402 milliseconds
Best Regards,
Saravanan N

Performance Tuning Tips

Dear All,
In our project we are facing lot of problems with the Performance, users are compaining about the poor performance of the few reports and all, we are in the process of fine tuning the reports by following the all methods/suggestions provided by SAP ( like removing the select queries from Loops, For all entries , Binary serach etc )
But still I want to know from you people what can we check from BASIS percpective ( all the settings ) and also ABAP percpective to improve the performance.
And also I have one more query that what is " Table Statistics " , what is the use of this ...
Please give ur valueble suggestions to us in improving the performance .
Thanks in Advance !

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.
Internal Tables
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 # 13SORT 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.
Reward if usefull

Performance tuning of a function which is part of a package.

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