Use of Hints in performance tuning

Hi
Please let me know actual usage of hints in query tunging, how do we write hints of increase performnace.
let me know below query will gives better performnce. if hints are not use query will degrade performance.
SELECT /*+ ORDERED INDEX (b, jl_br_balances_n1) USE_NL (j b)
USE_NL (glcc glf) USE_MERGE (gp gsb) */
b.application_id ,
b.set_of_books_id ,
b.personnel_id,
p.vendor_id Personnel,
p.segment1 PersonnelNumber,
p.vendor_name Name
FROM jl_br_journals j,
jl_br_balances b,
gl_code_combinations glcc,
fnd_flex_values_vl glf,
gl_periods gp,
gl_sets_of_books gsb,
po_vendors p

You'll likely have better luck posting this to an Oracle database forum, such as this one: PL/SQL
The forum you have posted this to is for Oracle Policy Automation.
Kind regards,
Davin.

Similar Messages

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.

Performance Tuning Query on Large Tables

Hi All,
I am new to the forums and have a very specic use case which requires performance tuning, but there are some limitations on what changes I am actualy able to make to the underlying data. Essentially I have two tables which contain what should be identical data, but for reasons of a less than optimal operational nature, the datasets are different in a number of ways.
Essentially I am querying call record detail data. Table 1 (refered to in my test code as TIME_TEST) is what I want to consider the master data, or the "ultimate truth" if you will. Table one contains the CALLED_NUMBER which is always in a consistent format. It also contains the CALLED_DATE_TIME and DURATION (in seconds).
Table 2 (TIME_TEST_COMPARE) is a reconciliation table taken from a different source but there is no consistent unique identifiers or PK-FK relations. This table contains a wide array of differing CALLED_NUMBER formats, hugely different to that in the master table. There is also scope that the time stamp may be out by up to 30 seconds, crazy I know, but that's just the way it is and I have no control over the source of this data. Finally the duration (in seconds) can be out by up to 5 seconds +/-.
I want to create a join returning all of the master data and matching the master table to the reconciliation table on CALLED_NUMBER / CALL_DATE_TIME / DURATION. I have written the query which works from a logi perspective but it performs very badly (master table = 200,000 records, rec table = 6,000,000+ records). I am able to add partitions (currently the tables are partitioned by month of CALL_DATE_TIME) and can also apply indexes. I cannot make any changes at this time to the ETL process loading the data into these tables.
I paste below the create table and insert scripts to recreate my scenario & the query that I am using. Any practical suggestions for query / table optimisation would be greatly appreciated.
Kind regards
Mike
-------------- NOTE: ALL DATA HAS BEEN DE-SENSITISED
/* --- CODE TO CREATE AND POPULATE TEST TABLES ---- */
--CREATE MAIN "TIME_TEST" TABLE: THIS TABLE HOLDS CALLED NUMBERS IN A SPECIFIED/PRE-DEFINED FORMAT
CREATE TABLE TIME_TEST ( CALLED_NUMBER VARCHAR2(50 BYTE),
                                        CALLED_DATE_TIME DATE, DURATION NUMBER );
COMMIT;
-- CREATE THE COMPARISON TABLE "TIME_TEST_COMPARE": THIS TABLE HOLDS WHAT SHOULD BE (BUT ISN'T) IDENTICAL CALL DATA.
-- THE DATA CONTAINS DIFFERING NUMBER FORMATS, SLIGHTLY DIFFERENT CALL TIMES (ALLOW +/-60 SECONDS - THIS IS FOR A GOOD, ALBEIT UNHELPFUL, REASON)
-- AND DURATIONS (ALLOW +/- 5 SECS)
CREATE TABLE TIME_TEST_COMPARE ( CALLED_NUMBER VARCHAR2(50 BYTE),
                                   CALLED_DATE_TIME DATE, DURATION NUMBER )
COMMIT;
--CREATE INSERT DATA FOR THE MAIN TEST TIME TABLE
INSERT INTO TIME_TEST ( CALLED_NUMBER, CALLED_DATE_TIME,
DURATION ) VALUES (
'7721345675', TO_DATE( '11/09/2011 06:10:21 AM', 'MM/DD/YYYY HH:MI:SS AM'), 202);
INSERT INTO TIME_TEST ( CALLED_NUMBER, CALLED_DATE_TIME,
DURATION ) VALUES (
'7721345675', TO_DATE( '11/09/2011 08:10:21 AM', 'MM/DD/YYYY HH:MI:SS AM'), 19);
INSERT INTO TIME_TEST ( CALLED_NUMBER, CALLED_DATE_TIME,
DURATION ) VALUES (
'7721345675', TO_DATE( '11/09/2011 07:10:21 AM', 'MM/DD/YYYY HH:MI:SS AM'), 35);
INSERT INTO TIME_TEST ( CALLED_NUMBER, CALLED_DATE_TIME,
DURATION ) VALUES (
'7721345675', TO_DATE( '11/09/2011 09:10:21 AM', 'MM/DD/YYYY HH:MI:SS AM'), 30);
INSERT INTO TIME_TEST ( CALLED_NUMBER, CALLED_DATE_TIME,
DURATION ) VALUES (
'7721345675', TO_DATE( '11/09/2011 06:18:47 AM', 'MM/DD/YYYY HH:MI:SS AM'), 6);
INSERT INTO TIME_TEST ( CALLED_NUMBER, CALLED_DATE_TIME,
DURATION ) VALUES (
'7721345675', TO_DATE( '11/09/2011 06:20:21 AM', 'MM/DD/YYYY HH:MI:SS AM'), 20);
COMMIT;
-- CREATE INSERT DATA FOR THE TABLE WHICH NEEDS TO BE COMPARED:
INSERT INTO TIME_TEST_COMPARE ( CALLED_NUMBER, CALLED_DATE_TIME,
DURATION ) VALUES (
'7721345675', TO_DATE( '11/09/2011 06:10:51 AM', 'MM/DD/YYYY HH:MI:SS AM'), 200);
INSERT INTO TIME_TEST_COMPARE ( CALLED_NUMBER, CALLED_DATE_TIME,
DURATION ) VALUES (
'00447721345675', TO_DATE( '11/09/2011 08:10:59 AM', 'MM/DD/YYYY HH:MI:SS AM'), 21);
INSERT INTO TIME_TEST_COMPARE ( CALLED_NUMBER, CALLED_DATE_TIME,
DURATION ) VALUES (
'07721345675', TO_DATE( '11/09/2011 07:11:20 AM', 'MM/DD/YYYY HH:MI:SS AM'), 33);
INSERT INTO TIME_TEST_COMPARE ( CALLED_NUMBER, CALLED_DATE_TIME,
DURATION ) VALUES (
'+447721345675', TO_DATE( '11/09/2011 09:10:01 AM', 'MM/DD/YYYY HH:MI:SS AM'), 33);
INSERT INTO TIME_TEST_COMPARE ( CALLED_NUMBER, CALLED_DATE_TIME,
DURATION ) VALUES (
'+447721345675#181345', TO_DATE( '11/09/2011 06:18:35 AM', 'MM/DD/YYYY HH:MI:SS AM')
, 6);
INSERT INTO TIME_TEST_COMPARE ( CALLED_NUMBER, CALLED_DATE_TIME,
DURATION ) VALUES (
'004477213456759777799', TO_DATE( '11/09/2011 06:19:58 AM', 'MM/DD/YYYY HH:MI:SS AM')
, 17);
COMMIT;
/* --- QUERY TO UNDERTAKE MATCHING WHICH REQUIRES OPTIMISATION --------- */
SELECT MAIN.CALLED_NUMBER AS MAIN_CALLED_NUMBER, MAIN.CALLED_DATE_TIME AS MAIN_CALL_DATE_TIME, MAIN.DURATION AS MAIN_DURATION,
     COMPARE.CALLED_NUMBER AS COMPARE_CALLED_NUMBER,COMPARE.CALLED_DATE_TIME AS COMPARE_CALLED_DATE_TIME,
     COMPARE.DURATION COMPARE_DURATION
FROM
SELECT CALLED_NUMBER, CALLED_DATE_TIME, DURATION
FROM TIME_TEST
) MAIN
LEFT JOIN
SELECT CALLED_NUMBER, CALLED_DATE_TIME, DURATION
FROM TIME_TEST_COMPARE
) COMPARE
ON INSTR(COMPARE.CALLED_NUMBER,MAIN.CALLED_NUMBER)<> 0
AND MAIN.CALLED_DATE_TIME BETWEEN COMPARE.CALLED_DATE_TIME-(60/86400) AND COMPARE.CALLED_DATE_TIME+(60/86400)
AND MAIN.DURATION BETWEEN MAIN.DURATION-(5/86400) AND MAIN.DURATION+(5/86400);

What does your execution plan look like?

Performance Tuning Section in Business Blueprint

Dear Gurus,
I am at a client location doing a blueprint. We are in the closure level of the business blueprint and one of the sections need to be added is the Performance Tuning. Can anybody suggest me what would be content to be added in the Performance Tuning section of blueprint. If anybody got the content section with them please forward that to my mail id, i.e. [email protected]
Thanks and regards
Vijay

Hi,
Think abt all BI is made up of an dhow to tune them..
Some hints:
1 Performance tuning for data loads : ( number range buffering, parallel loading..pseudo delta..chnging technical properties of tables if rec >100,000...IDOC clogging...etc)
2) Performnce tuing for Queries Aggregate...Cube modelling, OLAP cache....efficient multiprovider queries.etc.)
MEntion about transactiona whoich you will require for these things..such as RSRV..RSRTRACE..STO3n..ST05..etc...
gaurav

Is using Parallel Hint /*+PARALLEL */ good or bad?

Hi,
I am facing problem in using /*+ PARALLEL */ hint in SQL Query its taken long time to execute.
Is using PARALLEL Hint degrades performance?
The Table FCT_TABLE is having PARALLEL ( DEGREE DEFAULT INSTANCES DEFAULT ) clause.
We are using parallel hint as SELECT /*+ PARALLEL(FCT_TABLE 2)
Any help will be needful for me.
Thanks and Regards

user598986 wrote:
We have noticed the following from the Server:
1.The Disk I/O is showing 0 always during the time of Execution of the Query.
2.The I/O Adapter is showing 700%.What is the o/s and version? Do you use any virtualisation? What storage system do you use? What RAID levels, if any? And how did you monitor these results?
Note that the physical I/O layer is not part of the database layer. From the database layer you typically address I/O issues with
- logical design (e.g. normalise data so that there's a single copy of the data to maintain and thus less I/O)
- physical design (e.g. use partitioning, IOTs, clusters, indexes and so on to facilitate less I/O to process data)
- parallelise (use multiple processes to perform large I/O scans to address some of the inherited latency issues when doing I/O)
- reduce I/O (e.g. by truncating a table or partition instead of deleting it, using CTAS, design s/w that only needs to make a single pass through a data set, etc)
From the database app level you have no control over where the data is stored, how it is stored and cached. So, as PL/SQL or app developer, your primary concern should be the amount of I/O your data model and app needs - as that is something you can and do control. And not worry about the physical implementation of the I/O layer. As that should be the concern of the sys admin and DBA of that platform.

Privilleges for performance tuning

can we assign any specific privilleges to DBA for the performance tuning.
i dont want to give sysdba and sysopr privilleges to DBA.

The question should be why there is need to tune anything in Oracle database. What is the problem, have you defined the problem in a very clear manner ? Is there anything which is called problem or it is something other one ? What performance tuning tool you are going to use and why ?
Performance tuning is only two words, but it is very big topic; a topic on which 100 books / blogs have been written and still writing going on.
What and why are you trying to tune and what ORA you got ? As such there is no ready made role in oracle which says something like "PT_ROLE". We just issue the sql to the dictionary objects and as and when we gets privileges related error, we provides select on those sys objects to user; if he really needs though.
Regards
Girish Sharma

Can anyone plz tell me the steps for performance tuning.

hello friends
what is performance tuning?
can anyone plz tell me the steps for performance tuning.

Hi Kishore, this will help u.
Following are the different tools provided by SAP for performance analysis of an ABAP object
Run time analysis transaction SE30
This transaction gives all the analysis of an ABAP program with respect to the database and the non-database processing.
SQL Trace transaction ST05
The trace list has many lines that are not related to the SELECT statement in the ABAP program. This is because the execution of any ABAP program requires additional administrative SQL calls. To restrict the list output, use the filter introducing the trace list.
The trace list contains different SQL statements simultaneously related to the one SELECT statement in the ABAP program. This is because the R/3 Database Interface - a sophisticated component of the R/3 Application Server - maps every Open SQL statement to one or a series of physical database calls and brings it to execution. This mapping, crucial to R/3s performance, depends on the particular call and database system. For example, the SELECT-ENDSELECT loop on the SPFLI table in our test program is mapped to a sequence PREPARE-OPEN-FETCH of physical calls in an Oracle environment.
The WHERE clause in the trace list's SQL statement is different from the WHERE clause in the ABAP statement. This is because in an R/3 system, a client is a self-contained unit with separate master records and its own set of table data (in commercial, organizational, and technical terms). With ABAP, every Open SQL statement automatically executes within the correct client environment. For this reason, a condition with the actual client code is added to every WHERE clause if a client field is a component of the searched table.
To see a statement's execution plan, just position the cursor on the PREPARE statement and choose Explain SQL. A detailed explanation of the execution plan depends on the database system in use.
Need for performance tuning
In this world of SAP programming, ABAP is the universal language. In most of the projects, the focus is on getting a team of ABAP programmers as soon as possible, handing over the technical specifications to them and asking them to churn out the ABAP programs within the given deadlines.
Often due to this pressure of schedules and deliveries, the main focus of making a efficient program takes a back seat. An efficient ABAP program is one which delivers the required output to the user in a finite time as per the complexity of the program, rather than hearing the comment I put the program to run, have my lunch and come back to check the results.
Leaving aside the hyperbole, a performance optimized ABAP program saves the time of the end user, thus increasing the productivity of the user, and in turn keeping the user and the management happy.
This tutorial focuses on presenting various performance tuning tips and tricks to make the ABAP programs efficient in doing their work. This tutorial also assumes that the reader is well versed in all the concepts and syntax of ABAP programming.
Use of selection criteria
Instead of selecting all the data and doing the processing during the selection, it is advisable to restrict the data to the selection criteria itself, rather than filtering it out using the ABAP code.
Not recommended
Select * from zflight.
Check : zflight-airln = LF and zflight-fligh = BW222.
Endselect.
Recommended
Select * from zflight where airln = LF and fligh = 222.
Endselect.
One more point to be noted here is of the select *. Often this is a lazy coding practice. When a programmer gives select * even if one or two fields are to be selected, this can significantly slow the program and put unnecessary load on the entire system. When the application server sends this request to the database server, and the database server has to pass on the entire structure for each row back to the application server. This consumes both CPU and networking resources, especially for large structures.
Thus it is advisable to select only those fields that are needed, so that the database server passes only a small amount of data back.
Also it is advisable to avoid selecting the data fields into local variables as this also puts unnecessary load on the server. Instead attempt must be made to select the fields into an internal table.
Use of aggregate functions
Use the already provided aggregate functions, instead of finding out the minimum/maximum values using ABAP code.
Not recommended
Maxnu = 0.
Select * from zflight where airln = LF and cntry = IN.
Check zflight-fligh > maxnu.
Maxnu = zflight-fligh.
Endselect.
Recommended
Select max( fligh ) from zflight into maxnu where airln = LF and cntry = IN.
The other aggregate functions that can be used are min (to find the minimum value), avg (to find the average of a Data interval), sum (to add up a data interval) and count (counting the lines in a data selection).
Use of Views instead of base tables
Many times ABAP programmers deal with base tables and nested selects. Instead it is always advisable to see whether there is any view provided by SAP on those base tables, so that the data can be filtered out directly, rather than specially coding for it.
Not recommended
Select * from zcntry where cntry like IN%.
Select single * from zflight where cntry = zcntry-cntry and airln = LF.
Endselect.
Recommended
Select * from zcnfl where cntry like IN% and airln = LF.
Endselect.
Check this links
http://www.sapdevelopment.co.uk/perform/performhome.htm
https://www.sdn.sap.com/irj/sdn/go/portal/prtroot/docs/library/uuid/afbad390-0201-0010-daa4-9ef0168d41b6
kindly reward if found helpful.
cheers,
Hema.

Use of hints in query performance

Hi
Please let me know actual usage of hints in query tunging, how do we write hints of increase performnace.
let me know below query will gives better performnce. if hints are not use query will degrade performance.
SELECT /*+ ORDERED INDEX (b, jl_br_balances_n1) USE_NL (j b)
USE_NL (glcc glf) USE_MERGE (gp gsb) */
b.application_id ,
b.set_of_books_id ,
b.personnel_id,
p.vendor_id Personnel,
p.segment1 PersonnelNumber,
p.vendor_name Name
FROM jl_br_journals j,
jl_br_balances b,
gl_code_combinations glcc,
fnd_flex_values_vl glf,
gl_periods gp,
gl_sets_of_books gsb,
po_vendors p

942919 wrote:
Please let me know actual usage of hints in query tunging, how do we write hints of increase performnace.The majority of hints would be used to diagnose a performance problem by identifying a better query plan and fixing the underlying reason that the optimizer did not select that plan automatically. Hints used in this way would be removed from the query after the cause of the performance problem was fixed.
http://docs.oracle.com/cd/E11882_01/server.112/e16638/hintsref.htm#i8327
Hints change the access paths and methods the optimizer chooses, so before using a hint, you need to understand what the optimizer does, what access methods are, when they are chosen, and what they are best used for.
To do that you need to read the Performance Tuning Guide
http://docs.oracle.com/cd/E11882_01/server.112/e16638/toc.htm
At a minimum reading and understanding these sections -
http://docs.oracle.com/cd/E11882_01/server.112/e16638/perf_overview.htm#i1006218
http://docs.oracle.com/cd/E11882_01/server.112/e16638/optimops.htm#i21299
http://docs.oracle.com/cd/E11882_01/server.112/e16638/ex_plan.htm#i19260
http://docs.oracle.com/cd/E11882_01/server.112/e16638/stats.htm#i13546
Then you should be able to use a hint safely.
let me know below query will gives better performnce. if hints are not use query will degrade performance.Not true, hints change the performance of queries they can make them slower as well as faster. Here is an example of an index hint slowing down a query
{message:id=1989089}

Performance tuning - Hints

Hi Experts,
I am new to oracle database developer. currently i am leraning the performance tuning.
I have a question that is it a good practice to use hint as having using oracle database version 10g.
some where i have read and also some Senior members from suggest me that before 9i the optimizer was rule based , hence there was nesecarry to use hint.
after 9i onwards the optimeser is cost based hence there is no need to provide the hints.
but i have seen some queries from the expert where they have used hints.( even in db version 10g).
so can you please tell me that if we wants to use hints then when to use them>\
thanks in advance
Prashant Mhatre

> Senior members from suggest me that before 9i the optimizer was rule based
No, the CBO was introduced in Oracle 7.
> so can you please tell me that if we wants to use hints then when to use them>
Hints can be handy during development for tuning and tweaking (but not twerking).
In production code, hints can be poison. Some of the worst performance problems I've seen were *caused* by inappropriate hints.
Keep in mind I'm talking about "tuning hints". There are some other hints (like insert /*+ append */) that fall into a totally different category.

Performance tuning of database using DBACOCKPIT

Hiii Experts,
I have installed new server with OS:- Windows server 2012 and DB:- Sybase ASE 15.07.
Now I want to perform performance tuning of SAP and Database, so for that I have configured
DBACOCKPIT but I could not change the parameter values so could you tell me how to change
parameter values and how to use DBACOCKPIT for performance tuning.
Thank you,
Regards,
Omkar M.

DBA_Guide wrote:
Reports running slow, not sure if database is using Start transformation for the Datawarehouse Database.
Used hint */+ STAR_TRANSFORMATION */, still no performance increase.
Checked database parameter -
SQL> show parameter star;
NAME                                 TYPE        VALUE
dg_broker_start                      boolean     FALSE
fast_start_io_target                 integer     0
fast_start_mttr_target               integer     0
fast_start_parallel_rollback         string      LOW
log_archive_start                    boolean     FALSE
star_transformation_enabled          string      TRUE
Any Help is appreciated.
Thanks!
If star transformation was not the cause of the slowness, of course it won't make it faster.
I bet you any number of other different hints will result in no change in performance.
This is like replacing gas tank on your car with a LARGER tank & filling it with more gasoline to make the car go faster.
The amount of gasoline is not a factor that limits the speed of your car.

Can i use "Oracle Database 12c: Performance Management and Tuning " training for getting certification on "Oracle Database 11g: Performance Tuning 1Z0-054"

i have taken "Oracle Database 12c: Performance Management and Tuning new" training from oracle university. Now i would like to get certified on "Oracle Database 11g: Performance Tuning 1Z0-054" exam. Is it possible ?

I essentially endorse and refer you to Matthews' and John's post above.
I would differ with slightly with Matthew because my guess is you would often be able to use like for like 12c training for an 11g certification ( I believe there are precedents). BEFORE ANYONE ASKS THE OTHER WAY DOESN'T HAPPEN.
.... but totally concur with Matthew you would ill advised to procede on that basis without one of:
- This being advertised as possible on the website : e.g. https://education.oracle.com/pls/web_prod-plq-dad/db_pages.getpage?page_id=654&get_params=p_id:169 ... option 2 show courses.
- Confirmation from Brandye
- Confirmation from an Oracle Certification Support Web Ticket ( http://education.oracle.com/pls/eval-eddap-dcd/OU_SUPPORT_OCP.home?p_source=OCP )
... The more common (and in my opinion usually better) way would be get your 11g DBA OCP ( or higher first) and then take the 1z0-054. I am almost certain they will accept your 12c course for the 11g DBA OCP.
If you are choosing the route of not being a 11g (or 12c ) DBA OCP first but are on option 2 and relying on the course for certification then the issue is more in the balance and you are even more strongly advised to get confirmation before proceding (remember if the rules need to be changed for you only then any profit out of the exam is lost).
In general my understanding is Oracle would prefer to encourage people to train on the latest version of product that is available for training and will prefer to avoid restrictions which would cause you to train at a lower version. ( This is simply my guess at Oracle University Policy ... personal opinion only).
Having said all I have said I'd encourage you to go with the advice of the earlier two posts.

IPhone Performance Tuning Using Shark

Hi, I'm trying to do some performance tuning and am having some trouble using Shark.
*Problem #1*: No matter what configuration I choose ( debug, release, simulator, device ) the "Shark" menu item under "Run" in XCode is greyed out. How do I enable this feature so I can run my application using Shark through XCode?
*Problem #2*: I've been able to run Shark on it's own while my iPhone simulator is running and have tried to capture my application. However, for some reason my application name "TestApp" shows up multiple times in the drop down in Shark when selecting which process to monitor. They all have the "TestApp" and most of them have a number after it such as 94452. Any ideas on why this happens and which one is the process I should choose?
*Problem #3*: I've tried simply selecting one of the four or five "TestApp" processes from the Shark drop down and running it. It does capture information and gives me the results, however most of the symbols are missing even though my project has "Gererate Debug Symbols" check box checked in the project settings. Is there something else I need to do in order to get all symbols to show up?
My hope is that by fixing problem #1, it will automatically fix problems #2 and #3.
Any help would be great! Thanks!
Message was edited by: BPerfetto

ghostrocket wrote:
Steven Boswell wrote:
#3: From Shark, select File -> Symbolicate... and choose the original version of the executable you're running on your iPhone.
where is the original version of the executable on the filesystem? i can't seem to find it.
Look in your project's folder. It's in the "build" folder, in another folder probably named "Debug-iphoneos". When you choose the right file, (the executable, not the ".dSYM" file), the bottom of the file panel will fill out in black with information. If you choose the wrong one (like the simulator executable), the information in the file open panel will be red and you'll get an error message.
charlie

Performance tuning Issue

Hi folks,
I having a problem with performance tuning ... Below is a sample query
SELECT /*+ PARALLEL (K 4) */ DISTINCT ltrim(rtrim(ibc_item)), substr(IBC_BUSINESS_CLASS, 1,1)
FROM AAA K
WHERE ltrim(rtrim(ibc_item)) NOT IN
select /*+ PARALLEL (II 4) */ DISTINCT ltrim(rtrim(THIRD_MAINKEY)) FROM BBB II
WHERE SECOND_MAINKEY = 3
UNION
SELECT /*+ PARALLEL (III 4) */ DISTINCT ltrim(rtrim(BLN_BUSINESS_LINE_NAME)) FROM CCC III
WHERE BLN_BUSINESS_LINE = 3
The above query is having a cost of 460 Million. I tried creating index but oracle is not using index as a FT scan looks better. (I too feel FT scan is the best as 90% of the rows are used in the table)
After using the parallel hint the cost goes to 100 Million ....
Is there any way to decrease the cost ...
Thanks in advance for ur help !

Be aware too Nalla, that the PARALLEL hint will rule out the use of an index if Oracle adheres to it.
This is what I would try:
SELECT /*+ PARALLEL (K 4) */ DISTINCT TRIM(ibc_item), substr(IBC_BUSINESS_CLASS, 1,1)
FROM AAA K
WHERE NOT EXISTS (
SELECT 1
    FROM BBB II
WHERE SECOND_MAINKEY = 3
      AND TRIM(THIRD_MAINKEY) = TRIM(K.ibc_item))
AND NOT EXISTS (
SELECT 1
    FROM CCC III
WHERE BLN_BUSINESS_LINE = 3
    AND TRIM(BLN_BUSINESS_LINE_NAME) = TRIM(K.ibc_item))But I don't like this at all: TRIM(K.ibc_item), and you never need to use DISTINCT with NOT IN or NOT EXISTS.
Try this:
SELECT DISTINCT TRIM(ibc_item), substr(IBC_BUSINESS_CLASS, 1,1)
FROM AAA K
WHERE NOT EXISTS (
SELECT 1
    FROM BBB II
WHERE SECOND_MAINKEY = 3
      AND TRIM(THIRD_MAINKEY) = K.ibc_item
AND NOT EXISTS (
SELECT 1
    FROM CCC III
WHERE BLN_BUSINESS_LINE = 3
    AND TRIM(BLN_BUSINESS_LINE_NAME) = K.ibc_itemThis may not work though, since you may have whitespaces in K.ibc_item.

IIR 2.8.0.7 performance tuning suggestions / documents for Oracle 11?

Would we have any hints or white papers that would support a customer in IIR matching server tuning for initial load performance,
beyond the Siebel specific
Performance Tuning Guidelines for Siebel CRM Application on Oracle Database (Doc ID 781927.1)
which does NOT generate any statistics on the Informatica Schema?
Customer is starting production data load into Siebel UCM of over 5 million customer records . Their current bottle neck seems to be IIR queries and high IIR host resources usage.
This would be for Siebel 8.1.1.4 [21225] on Oracle 11.1.0.6; I currently do not know if ACR 475 with its EBC access is used or not; I'd be looking for any performance tuning suggestions on the Informatica & database side - I have not found anything helpful in the informatica knowledgebase and in the 2.8.0.7 docs the only performance tuning suggestions seem to be on IDT loads.
Obviously performance can be influenced by the matching fields used, but this customer will be looking for performance tuning suggestions keeping the matching fields and thresholds they got approved from the business side.
Any documents we could share?

Hi Varad,
Well, Oracle Metalink actually got it fixed for me! Got to give them credit.
I ran the 1st bit of SQL they sent me and it fixed it so I think it was only cosmetic. I've enclosed all of their response in case others may find themselves in similar situation.
Thanks again for YOUR help too.
Perry
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1. Do you see any invalid objects in the database?
2. Please update the SR with the output of running the commands below
1.Connect as SYS.
set serveroutput on (This will let you see if any check fails)
exec validate_apex; (If your version is 2.0 or above)
If all are fine, the registry should be changed to VALID for APEX and you should see the following
message:
PL/SQL procedure successfully completed.
Note : The procedure validate_apex should always complete successfully.
With serveroutput on, it should show why Application Express is listed as invalid.It should show output like:
FAILED CHECK FOR <<obect_name>>
Or
FAILED EXISTENCE CHECK FOR <<object_name>>

Performance Tuning DBA fix not Applications fix

Hi
I had an interview , which the DBA team leader was asking me about my performance tuning expereince
i was answering about my expereince in tuning the sqls and get a good statistics so the CBO choose the best plan, or even hint my sqls so i force the best plan
the interviwer was worried because this is an application tuning , not a DBA tuning
he mention that he want to hear that i changed a db parameter that enhance the performance , or chnage any thing in the DBA side that tune the performance
Anybody have an example of changing a parameter or something DBAish that help the performance?
Thanks for any contribution

You should read following sections of Performance Tuning Guide:
Performance Considerations for Initial Instance Configuration:
http://download.oracle.com/docs/cd/B19306_01/server.102/b14211/build_db.htm#i20151
Memory Configuration and Use:
http://download.oracle.com/docs/cd/B19306_01/server.102/b14211/memory.htm#i53187
Oracle Instance Tuning Using Dynamic Views:
http://download.oracle.com/docs/cd/B19306_01/server.102/b14211/instance_tune.htm#i35312

Use of Hints in performance tuning

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