Database performance tuning Question

Please,
The top wait event having all the time when tuning, oracle database is the following.
enq: TX - row lock contention
What could be the best way to pinpoint the cause of this?.
I'm on Oracle 10g, windows server 2003.
Thanks

The first thing to do is check the underlying reason. If you query v$session_wait_history or v$lock when you spot a lock appearing, you can check if the request is for mode 4 or mode 6.
Mode 6 means you are colliding on an attempt to update the data in a heap table. Mode 4 can mean many things - including a few "internal" problems, which is probably why the comment about initrans appeared - but often means you have a collision on indexes, (e.g. pending duplicates in unique indexes, conflicts in parent/child referential integrity) or colliding updates to the non-key part of IOTs.
If you are allowed to use v$active_session_history, you can query that to find the sql_id of a session that was waiting for a lock and then be able to see the SQL that the waiting session was trying to operate - otherwise you may have to catch it waiting and check v$session for the sql_id.
Once you have the SQL, you may have a better idea of why the lock was happening.
Regards
Jonathan Lewis
http://jonathanlewis.wordpress.com
http:/www.jlcomp.demon.co.uk

Similar Messages

Oracle 11 G database performance tuning

How to indexing the oracle 11G database?
Thanks in advance.

Your question is like if you ask "Tell me how to fix a car". As you know people spend years learning how to fix different problems with cars; the same applies to database performance tuning. There is no way to answer this question in one post. Please ask a more specific question in an apropriate (database related) forum.
cheers

Performance Tuning Question

Greetings,
I did a few searches for any topics related to this and
haven't found anything relevant - if I'm missing something obvious
I apologize.
We are doing some performance tuning of a CFMX 7.0.2 system
running on Solaris. Of the many things we're doing one is to run
truss on the cfmx processes to find out what in fact it's doing.
The following is an excerpt from one of the truss outputs:
stat64("/opt/coldfusionmx7/runtime/../lib/macromedia/jdbc/sqlserver/SQLServerURLParser.cla ss\0",
0x254FB860, 0x254FB9BC) = -1 Err#2
stat64("/opt/coldfusionmx7/runtime/../gateway/lib/macromedia/jdbc/oracle/OracleURLParser.c lass\0",
0x254FB860, 0x254FB9BC) = -1 Err#2
Err #2 means "File not found" in essence
These lines show up quite a bit in the output - and we're
curious as to why it's trying to find those particular classes at
all and why in those locations - there are other entries where it
looks like it's going through a series of paths that it knows about
trying to find these entries. As we use Oracle as our database what
could be the reason it's looking for SQLServer? Finally does anyone
know of a way to stop the attempt to find these classes and save
the system processing time to give us back those cycles for real
work?
Regards,
Scott

Please try:
Create View View3
As
SELECT a.Col1, a.Col2
From dbo.TableA A
WHERE NOT Exists (SELECT 1 From dbo.TableB B With(NoLock) WHERE A.Col1 = B.Col1)
UNION
SELECT Col1, Col2 From dbo.TableB
Also, please make sure that INDEXes on Col1 on both tables are NOT fragmented and your STATISTICS are also up tp date.
Best Wishes, Arbi; Please vote if you find this posting was helpful or Mark it as answered.

Check the database ( Performance , tuning , . . . . . . . , etc )

Dears,,
If i have running database and i need to make check health for it for performance , tuning , . . . , etc
Is there any steps or advisors or documentations to go ahead with them enable me to check the database health.
Thanks & Regards,,

Eng.Mohammed wrote:
Dears,,
If i have running database and i need to make check health for it for performance , tuning , . . . , etc
Is there any steps or advisors or documentations to go ahead with them enable me to check the database health.
Thanks & Regards,,
One way to check for performance issues is to see if your telephone is ringing. If no one is calling to complain, then you don't have any problems.
I'm only half joking. Which means I am half serious. While you shouldn't take a completely cavalier attitude toward performance, neither do you want to fall victim to Compulsive Tuning Disorder.
Start with the 2-Day DBA manual. Follow up with the tuning guide. Both at tahiti.oracle.com
And remember, no matter how much effort you put into tuning, there will always be a "Top Five" wait events. Is it worth 40 man hours of effort to get a 75% reduction in average response time? Really? Even if the average response time is already 0.5 seconds? Is the user going to be able to perceive that 0.38 seconds improvement?

Database performance tuning

i have a very large database consisting of around 300,000,000 records with 38 columns in each record.
i need help in tuning the database so that query results don't take more than a few seconds.
the data is the log of events occuring in the SMSC server.
there are about 10,000,000 events daily.
Search criteria is usually time range and the mobile numbers.
Please advise on the sql and table structure to be used for best performance.presently using composite partitioning with range partitioning based on time( one partition for each day). query with 1 day range takes about 70-80 seconds.
i'm using java servlets and jdbc for accessing the database.
there's no problem in inserting data.

Hi
Thanks for your replies.
The table structure is as follows :
LOGGING_TIME DATE
LOG_TYPE NUMBER
SUC_INDICATOR NUMBER
ORIG_IW_TYPE NUMBER
ORIG_TYPE NUMBER
ORIG_ADDR VARCHAR2(21)
ORIG_ADDR_LEN NUMBER
DEST_IW_TYPE NUMBER
DEST_TYPE NUMBER
DEST_ADDR VARCHAR2(21)
DEST_ADDR_LEN NUMBER
SMS_CENTRE VARCHAR2(21)
INCOMING_TIME DATE
TIME DATE
ERROR_CAUSE NUMBER
ERROR_ORIGINATOR NUMBER
NO_OF_ATTEMPTS NUMBER
TARIFF_CLASS NUMBER
MSG_LEN NUMBER
PID NUMBER
SR_REQUEST NUMBER
DEFERRED_DEL NUMBER
SERV_DESC NUMBER
REF_NR NUMBER
MAX_NR NUMBER
SEQ_NR NUMBER
SP_MSG_IND NUMBER
DCS NUMBER
ACCESS_METHOD NUMBER
PRIORITY NUMBER
SENDER_CHG_TYPE NUMBER
RECIPIENT_CHG_TYPE NUMBER
SENDER_PREPAID_STATUS NUMBER
RECIPIENT_PREPAID_STATUS NUMBER
CHARGED_PARTY NUMBER
VMSC VARCHAR2(21)
ORIG_IMSI VARCHAR2(21)
CONSO_MSG VARCHAR2(10)
I have used composite partitioning with range partition based on logging_time and one day for each partition.there are 32 subpartitions.
I have created a local partitioned index on columns logging_time,orig_addr and dest_addr respectively as they are the most commonly used in queries.
query : select /*+ parallel_index(event_logs, event_logs_ind2)*/ * from event_logs where (logging_time>=?) and (logging_time<?) and (orig_addr like ?) and (log_type like ?) and (dest_addr like ?) order by logging_time
execution plan is as follows:
select statement
partition range(iterator)
     sort(order by)
     partition hash(all)
          table access(by local index rowid) of "smsevent.event_logs"
          index(range scan) of "smsevent.event_logs_ind"(non-unique)
I tried to make this more readable but the white spaces are getting removed from the posted message.
looking forward to a quick response

Answers to these performance tuning questions 9i

what are the answers to the below questions ??
367. You have used the ALTER command to set the DB_CACHE_ADVICE parameter to READY. What is now happening in the instance?
A. Memory has been allocated in the shared pool for cache advice buffers.
B. CPU utilization will significantly increase because Oracle is collecting more detailed statistics about the buffer cache.
C. The buffer cache hit ratio will now increase.
D. The V$DB_CACHE_ADVICE view is now populated.
184. Which two statements are true regarding the use of DB_CACHE_ADVICE init.ora parameter? (Choose two)
A. Setting the parameter to READY reserves space in the buffer cache to store information about different buffer cache sizes, but no CPU overhead is incurred.
B. Setting the parameter to READY reserves space in the shared pool to store information about different buffer cache sizes, but no CPU overhead is incurred.
C. Setting the parameter to ON reserves space in the buffer cache to store information about different buffer cache sizes, and CPU overhead is incurred as statistics are collected.
D. The V$DB_CACHE_ADVICE view contains information that predicts the estimated number of physical reads for different cache sizes for each buffer cache setup in the SGA.
185. Which three statements are true with respect to has clusters? (Choose three)
A. Full table scans are generally faster on cluster tables than on non-clustered tables.
B. Hash clusters may be desirable when the number of key values is predictable and key values are evenly distributes.
C. If tables in a hash cluster require more space than the initial allocation for the cluster, performance degradation can be substantial because overflow blocks are required.
D. Storing a single table in a hash cluster can be useful regardless of whether the table is joined frequently with other tables or not, provided other criteria for choosing a hash cluster are met.
346. You have been seeing poor performance for inserts into a new table.
You queried V$WAITSTAT and V$SYSTEM_EVENT and determined that there is free list
contention in your database.
Next, you identified the segments by joining the DBA_SEGMENTS table and V$SESSION_WAIT
view to identify the file and block where waits are occurring.
What is the next step you should take?
A. If the file and block identify a data block within a table, consider increasing the number of free lists on the table using the ALTER TABLE command and specifying the FREELISTS clause.
B. If the file and block identify a data block within a table, consider increasing the number of free lists on the table using the ALTER TABLESPACE command and specifying the FREELISTS clause in the default storage clause.
C. If the file and block identify a segment header for a table, consider increasing the number of free lists on the table using the ALTER TABLE command and specifying the FREELISTS keyboard in the storage clause.
D. If the file and block identify a segment header for a table, consider increasing the number of free lists on the table using the ALTER TABLESPACE command and specifying the FREELIST clause in the default storage clause.
235. To provide more free lists for a number of your database segments, what is one of your options?
A. Modify them with the INSERT_ _FREELIST command.
B. Drop and re-create them with the required FREELIST value.
C. Change the default storage parameter of the tablespace(s) where they are stored.
D. Modify the FREELIST_LIMIT parameter in your installation file and restart the instance.
337. How to set the OPTIMIZER_MODE for minimizing total response time?
A. RULE
B. ALL_ROWS
C. FIRST_ROWS_n
D. FIRST_ROWS
347. You want to enhance performance of the Database Optimizer to minimize total response time, thereby increasing overall throughput of batch process.
Which choice identifies the best optimizer mode setting for meeting this requirement?
A. RULE
B. ALL_ROWS
C. FIRST_ROWS
D. FIRST_ROWS_n
Message was edited by:
Akshay

Let's turn this around ...
what do you think are the correct answers? and what is your logic?
All the answers are in the Concepts manual or the DB Administrator's Guide at http://docs.oracle.com ... use http://tahiti.oracle.com and you can search the docs very easily.

Performance tuning questions

i am fresher in sap-abap. so i have some doubts.
how to increase performance in a report. what r the minimum steps to follow.
expecting the answer more clearly

Hi Josh,
Here is a detailed document for performance check:
<b>AWARD POINTS IF IT HELPS:</b>
5.1     SQL
     In order to enhance the performance of your ABAP code a number of useful guidelines can be used.
     Use SELECT SINGLE wherever possible to retrieve up to one row of information. It is important to specify all the key fields to ensure a unique record.
     Be careful using the FOR ALL ENTRIES addition since this is very bad for very large datasets (10,000+ records)
     Joins and subqueries are good
     Do not use SELECT * statement unless the program needs ALL columns from the table. Instead, only specify the fields you require. This will also avoid unnecessary network transports. The addition INTO CORRESPONDING FIELDS of the INTO clause of the SELECT statement is worthwhile to use only for large amounts of data where the external table and destination fields have the same names. Consider the use of the DISTINCT option in the case of many duplicate entries.
     The following example compares selecting all fields to selecting only the document number, the item number and the material.
     Avoid:. select   *      from vbap
                                     where vbeln in s_docno.
               endselect.
     Use:     select vbeln posnr matnr
     into (wa_vbap-vbeln, wa_vbap-posnr, wa_vbap-matnr)
     from vbap
     where vbeln in s_docno.
               endselect.
Important Points:
     The order of the fields retrieved must match the order of the destination fields in the field list.
     Use the SELECT...WHERE clause to restrict data rather than retrieve all rows and use a CHECK or IF statements to filter data.
     Avoid:     select vbeln posnr matnr
     into (wa_vbap-vbeln, wa_vbap-posnr, wa_vbap-matnr)
     from vbap.
                  check s_docno.
               endselect.
     Use:     select vbeln posnr matnr
     into (wa_vbap-vbeln, wa_vbap-posnr, wa_vbap-matnr)
     from vbap
     where vbeln in s_docno.
               endselect.
Important Points:
     Order the columns in the where clause of a select in the same order as the key or index table.
     WHERE Clause Tips
o     Exploit the indexes of the database tables for an efficient use of the WHERE clause. To do so check all index fields with the equality operator (EQ, =) and concatenate these checks by AND. The primary key of a database table makes up its primary index automatically. Secondary indexes for a database table can be created in the ABAP Dictionary.
o     If possible, include all columns of the key or an index in the where clause. Use a default or appropriate value. If the column(s) is not included, the database may not be able to fully utilise the index.
o     Avoid complex WHERE clauses. The system must split up those into single statements for the database system.
o     Do not use the logical NOT in WHERE clauses but inverted operators instead. The logical NOT is not supported by the database indexes.
     Try to avoid the select endselect programming construct. Rather select all the required records from the database directly into an internal table and loop at the table to process the entries. This is usually faster than the select endselect code, and also allows easier debugging of the code.
     Avoid:     select vbeln posnr matnr
     into (wa_vbap-vbeln, wa_vbap-posnr, wa_vbap-matnr)
     from vbap
     where vbeln in s_docno.
                   write:/ wa_vbap-vbeln, wa_vbap-posnr, wa_vbap-matnr.
               endselect.
Use:     select vbeln posnr matnr into table ts_vbap
               from vbap
               where vbeln in s_docno.
          loop at ts_vbap into wa_vbap.
               write:/ wa_vbap-vbeln, wa_vbap-posnr, wa_vbap-matnr.
          Endloop.
     Avoid nested select statements if possible as they generally have poor performance. It is preferable to select all the entries for each table directly into an internal table and use nested internal table loops to process all the entries.
     Check runtime analysis tips and tricks for detailed comparisons in select performance (SM30). SELECT statements.
     Use aggregate expressions in the SELECT clause to perform calculations instead of transporting great amounts of data and calculating thereafter. This distributes the processing load and minimises the network data transfer. Valid aggregate functions include: MAX, MIN, AVG, SUM and COUNT.
     The storage of database tables in local buffers can lead to significant time savings. Use the buffering of database tables whenever possible. Use the addition BYPASSING BUFFER only if it is really necessary.
If DISTINCT, SINGLE FOR UPDATE, and aggregate expressions are used in the SELECT clause, buffering should be turned off.
     Provide the appropriate selection criteria to limit the number of data base reads. Force users to provide selection criteria by evaluating the selection criteria entered on the selection screen during the AT SELECTION-SCREEN event.
     Create indices where needed to enhance query performance. This should be used in large table lookups to increase efficiency. For example, SELECTWHERE FieldA = 001. In this case FieldA is not a key field, therefore an index should be created to improve the efficiency of the select statement. Beware that there is always an additional processing system overhead for indices. Therefore, only create indices if a major performance benefit will be realised, especially if the program concerned is executed many times throughout the day and is business critical.
5.1.1     SQL Checklist
     Keep the selected dataset small
     Keep the transferred data small
     Keep the number of database accesses small
     Use database buffers
     Create views for table joins instead of using multiple selects.
     Select data only one time where possible (i.e., dont have multiple selects against the same table - get the data one time and store it in an internal table).
     Remove unused indexes from tables.
5.2     General Programming Techniques
     Detailed below are a number of additional programming techniques that should be borne in mind when implementing ABAP code.
     When testing fields "equal to" something, one can use either the nested IF or the CASE statement. The CASE is better for two reasons. It is easier to read and the performance of the CASE is more efficient.
     Do not use MOVE CORRESPONDING unless the data is contiguous.
     When records a and b have the exact same structure, it is more efficient to MOVE a TO b than to MOVE-CORRESPONDING a TO b, if records a and b have the exact same structure.
               MOVE BSEG TO *BSEG. is better than
               MOVE-CORRESPONDING BSEG TO *BSEG.
     Do not use the COLLECT statement with large internal tables as this can be very CPU intensive.
     When reading a single record in an internal table, the READ TABLE WITH KEY is not a direct READ on a on a sorted table. Therefore, SORT the table and use READ TABLE WITH KEY BINARY SEARCH.
     Use the SORT...BY when sorting internal tables.
          SORT ITAB BY FLD1 FLD2. is more efficient than
               SORT ITAB.
     Avoid hard-coding and use of literals in ABAP code. Use reference tables to drive processing to support business change flexibility and reduce ongoing maintenance costs. If hard-coding and literals are required, be sure to include these as constants.
     The Tips & Tricks function is very useful in comparing different methods of coding without going to the trouble of coding both and then performing your own run-time analysis. System > Utilities > Runtime Analysis > Tips & Tricks.
5.3     Logical Databases
Use logical databases and GET events wherever reads on parent/child segments need to be performed e.g. require data from both MARA then MARD table - use GET MARA then GET MARD. (Note you do not need to use an LDB if data from only the MARA or MARD table is required.)
Where an LDB is used provide defaults or checks for the standard selection-options/parameters wherever possible.
Avoid use of logical data bases as much as possible - use SELECT statements instead. (Logical databases are good as a reference tool to look up database hierarchies).
          Logical database should only be used when there are no other options.
     Use of Logical database in ABAP programs must be approved by a DEVELOPMENT TEAM LEAD
     Due to strategic importance of LDBs and the potential impact on system performance, careful consideration should be made before creating new LDBs. Consequently no LDBs should be created without approval from the Development Team Lead
5.4     Debugging
When testing ABAP, use of the debugging tool plays an essential role in checking the value of variables during the execution of the program. This tool should be used during the unit testing to ensure programs are executing as desired.
You can use the debugging tool by selecting Program > Debugging from the ABAP program Development Initial screen.
In addition to the static programming of breakpoints, ABAPs on-line debugging tools also allow you to set breakpoints and interrupt conditions dynamically. This makes the whole process of debugging reports much more flexible and the consequent advantage is that you do not have to change your code. Watchpoints can now be set based on the value a field takes (like R/2).
Once you have stopped the report processing, you can view the contents of all the fields (up to 8), internal tables and database tables referenced in the report. The system fields SY-TABIX and SY-DBCNT are now displayed at the bottom of the screen along with SY-SUBRC.
Finally, you can change the contents of fields for debugging purposes and then resume report processing, with the changed data. To set breakpoints select Breakpoints > Set from the ABAP: Editor screen. Then execute the program.
Beware that in order to debug SAPscript programs, hard-coded breakpoints are often required. Be sure to remove these once testing is complete and the program transported. Use the syntax BREAK username, rather than BREAK-POINT, as this will ensure the code only stops when running under the specified username.
6     SAPscript Techniques
6.1     Good Practice
     Always copy the SAP standard print programs where available and, in most instances, the layout set. Never start a complex SAPscript (e.g. Invoice, Purchase Order) from the beginning, as this will require far more development time to complete.
     When creating a new layout set by copying a SAP standard, always change the original language from D to E and then activate.
6.2     Standards
     Naming convention for layout sets this will follow the same as the program name, except the version number will be prefixed L. For example a purchase order layout set would be:
ZMM_DESC where
Z          First character of the program
MM          SAP R/3 module/component
DESC          Meaningful description i.e. PO printing, INVOICE.
     When copying SAP standard print programs ensure they have a standard header block as defined earlier. Also ensure that any code that is added, removed or changed is commented in the standard fashion.
6.3     Standard Texts
     These should be of the following format:
     ZXX_DESC
Where:
Z          First character of the program
     XX          Module name
     DESC          Meaningful description.
6.4     Tips
     Text elements must be maintained individually for each layout set language. Any other changes to the layout set i.e. window size or paragraphs, will be copied from the original language to the other languages.
          As layout sets are client-dependant they must be transported between clients on the same box. To do this use the Copy from Client function from within the target client. This is language specific.
     Always ACTIVATE the layout set each change and in each language before transporting.
     The SAPscript debugger can be sent useful, this is turned on at the front screen on transaction SE71.
     Standard text used within a layout set must be assigned to a transport request using the program RSTXTRAN. Once assigned the transport request can be released in the usual manner via SE10.
7     Changing the SAP Standard
     You can adjust the R/3 System to meet your needs in the following ways:
o     Customizing: This means setting up specific business processes and functions for your system according to an implementation guide. The need for these changes has already been foreseen by SAP and an implementation procedure has been developed.
o     Personalization: This means making changes to certain fields' global display attributes (setting default values or fading fields out altogether), as well as creating user-specific menu sequences.
o     Modifications: These are changes to SAP Repository objects made at the customer site. If SAP delivers a changed version of the object, the customer's system must be adjusted to reflect these changes. Prior to Release 4.0B these adjustments had to be made manually using upgrade utilities. From Release 4.5A, this procedure has been automated with the Modification Assistant.
o     Enhancements: This means creating Repository objects for individual customers that refer to objects that already exist in the SAP Repository.
o     Customer Developments: This means creating Repository objects unique to individual customers in a specific namespace reserved for new customer objects.
     If your requirements cannot be met by Customizing or personalization, you may either start a development project or try using a CSP solution (= Complementary Software Product).
     A development project falls into the customer development category if the SAP standard does not already contain functions similar to the one you are trying to develop. If, however, a similar SAP function exists, try to assimilate it into your development project by either enhancing or modifying it, by using a user exit, or simply by making a copy the appropriate SAP program.
     Modifications can create problems, as new versions of SAP objects must be adjusted after an upgrade to coincide with modified versions of SAP objects you have created. Prior to Release 4.0B these adjustments had to be made manually using upgrade utilities. From Release 4.5A, this procedure has been automated with the Modification Assistant.
     Thus, you should only make modifications if:
     Customizing or personalizing cannot satisfy your requirements
     Enhancements or user exits are not planned
     It would not make sense to copy the SAP object to the customer namespace.
7.1     Originals and copies
     An object is original in only one system. In the case of objects delivered by SAP, the original system is at SAP itself. These objects are only copies in customer systems. This applies to your development system and all other systems that come after it.
     If you write your own applications, the objects that you create are original in your development system. You assign your developments to a change request, which has the type Development/Correction.
This request ensures that the objects are transported from the development system into the subsequent systems
7.2     Corrections and repairs
     Changes to an original are called corrections. They are recorded in a change request whose tasks have the type "Development/correction".
     If, on the other hand, you change a copy (an object outside its own original system), the change is recorded in a task with the type "Repair". Repairs to SAP objects are called modifications.
     When you repair your own objects (for example, if something goes wrong in your production system), you can correct the original in your development system straight away. When you change copies, you must correct the original immediately!
     However, you cannot do this with SAP objects, because they are not original in any of your systems.
     You should only modify the SAP standard if the modifications you want to make are absolutely necessary for optimizing workflow in your company. Be aware that good background knowledge of application structure and flow are important prerequisites for deciding what kind of modifications to make and how these modifications should be designed.
7.3     Modifications and upgrades
During an upgrade or an import of R/3 Support Packages, new objects delivered overwrite existing objects of the SAP standard. In order to help customers keep those objects that have been modified in a previous release, SAP now offers upgrade adjustment for all objects being upgraded in the form of transactions SPAU and SPDD. These transactions allow customers to enter their modifications into the corresponding new objects being delivered at upgrade. The Modification Assistant supports this process of adopting customer modifications. In general, objects altered using the Modification Assistant can now be automatically accepted into the upgraded system if the modifications undertaken in the original version do not directly overlap those made in the customer version. If collisions occur between the two versions at upgrade (naming collisions, or if SAP has deleted an object modified by a customer), the system offers semi-automatic adjustment support. In some cases, however, you may still have to manually adjust objects using ABAP Workbench tools.
     Whenever you upgrade your system, apply a support package, or import a transport request, conflicts can occur with modified objects.
     Conflicts occur when you have changed an SAP object and SAP has also delivered a new version of it. The new object delivered by SAP becomes an active object in the Repository of your system.
     If you want to save your changes, you must perform a modification adjustment for the objects. If you have a lot of modified SAP objects, your upgrade can be slowed down considerably.
     To ensure consistency between your development system and subsequent systems, you should only perform modification adjustments in your development system. The objects from the adjustment can then be transported into other systems.
7.4     Modifications Procedures
     A registered developer must register changes to SAP objects. Exceptions to this registration are matchcodes, database indexes, buffer settings, customer objects, patches, and objects whose changes are based on automatic generation (for example, in Customizing). If the object is changed again at a later time, no new query is made for the registration key. Once an object is registered, the related key is stored locally and automatically copied for later changes, regardless of which registered developer is making the change. For the time being, these keys remain valid even after a release upgrade.
     How do you benefit from SSCR (SAP Software Change Registration)?
o     Quick error resolution and high availability of modified systems
All objects that have been changed are logged by SAP. Based on this information, SAP's First Level Customer Service can quickly locate and fix problems. This increases the availability of your R/3 system.
o     Dependable operation
Having to register your modifications helps prevent unintended modification. This in turn ensures that your R/3 software runs more reliably.
o     Simplification of upgrades
Upgrades and release upgrades become considerably easier due to the smaller number of modifications.
7.5     Modifications Assistant
The aim of the Modification Assistant is to make modification adjustments easier. This is because (among other reasons) the modifications are registered in a different layer
     If you want to change an SAP object, you must provide the following information:
o     SSCR key
o     Change request
     The system informs you that the object is under the control of the Modification Assistant. Only restricted functions are available in the editor.
     You can switch the Modification Assistant on or off for the entire system by changing the R/3 profile parameter eu/controlled_modification. SAP recommends that you always work with the Modification Assistant.
     You can switch off the Modification Assistant for single Repository Objects. Once you have done so, the system no longer uses the fine granularity of the Modification Assistant.
     In modification mode, you have access to a subset of the normal editor tools. You can access these using the appropriate pushbuttons. For example, in the ABAP Editor, you can:
o     Insert
The system generates a framework of comment lines between which you can enter your source code.
o     Replace
Position the cursor on a line and choose Replace. The corresponding line is commented out, and another line appears in which you can enter coding. If you want to replace several lines, mark them as a block first.
o     Delete
Select a line or a block and choose Delete. The lines are commented out.
o     Undo modifications
This undoes all of the modifications you have made to this object.
o     Display modification overview
Choose this function to display an overview of all modifications belonging to this object.
7.6     Restoring the original
You can reset all of the modifications that you have made to the current object using the Modification Assistant by choosing this function. The record of the modifications is also deleted.
Remember that you cannot selectively undo modifications to an object. You can only undo modifications based on the "all or nothing" principle.
          Any modifications in standard SAP object will require proper justification and needs to be documented. The rights of modification the standard SAP object is limited to PROJECT MANGER only.
Cheers,
ashish.

Book for 1Z0-033 Oracle9i Database: Performance Tuning

Hi
are there are any recommended books for 1Z0-033 exam
regards
kedar

Moreover, You can refer the Instructor Led Training (ILT) Materials which provided by Oracle Authorized Institutions i.e. SQL * International, and also, practice the Oracle's self test software questions.
Best of luck.
Sabdar Syed.

Can Anybody Send Me The Latest Testking Pdf Of 1z0-033 (Performance Tuning

Hello,
Can Anybody Send Me The Latest Testking Pdf Of 1z0-033 (Performance Tuning
my email address is asiforacle [email protected]
Regards,
Asif Iqbal
Software Engineer. ( Karachi, Pakistan ).

The answer is surely NO but what I would like to ask for the sake of curiosity , why did you ask about Performance Tuning questions over Sql /Plsql forum , not on Database General Forum? Not that you should go there now and ask, just curious.
Tell you what, read the free book(yup free). Here it is,
http://download.oracle.com/docs/cd/B10501_01/server.920/a96533.pdf
You won't need anything else to read, not even that testking stuff too.
HTH
Aman....

Database Performance task

Hi,
Who takes up the task of database performance tuning....is it the BW consulant or anyother?
Thanks

JB
We actually never involve in Database performance tuning!, All the time DBA will handle the
database tuning according SAP notes. We all the time involve in loading and query perfomance issues.
Srinivas.D

Invalid statement in Performance Tuning Guide

Oracle® Database Performance Tuning Guide
10g Release 2 (10.2)
Part Number B14211-01
13 The Query Optimizer
http://download.oracle.com/docs/cd/B19306_01/server.102/b14211/optimops.htm#sthref1324
excerpt:
"You can specify fast full index scans with the initialization parameter OPTIMIZER_FEATURES_ENABLE or the INDEX_FFS hint. Fast full index scans cannot be performed against bitmap indexes."
Emphasis mine - Gints
Here is counterexample:
SQL> select * from v$version;
BANNER
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Prod
PL/SQL Release 10.2.0.1.0 - Production
CORE    10.2.0.1.0      Production
TNS for 32-bit Windows: Version 10.2.0.1.0 - Production
NLSRTL Version 10.2.0.1.0 - Production
SQL> create table blah (sex varchar2(1) not null, data varchar2(4000));
Table created.
SQL> insert into blah select 'F', lpad('a', 4000, 'a') from user_objects where rownum<=10;
10 rows created.
SQL> insert into blah select 'M', lpad('a', 4000, 'a') from user_objects where rownum<=10;
10 rows created.
SQL> commit;
Commit complete.
SQL> create bitmap index sexidx on blah(sex);
Index created.
SQL> exec dbms_stats.gather_table_stats(user, 'blah', cascade=>true)
PL/SQL procedure successfully completed.
SQL>
SQL> set autot traceonly expl
SQL> set lines 100
SQL> select count(*) from blah where sex = 'F';
SQL> /
Execution Plan
Plan hash value: 1028317341
| Id | Operation                     | Name   | Rows | Bytes | Cost (%CPU)| Time     |
|   0 | SELECT STATEMENT              |        |     1 |     2 |     1   (0)| 00:00:01 |
|   1 | SORT AGGREGATE               |        |     1 |     2 |            |          |
|   2 |   BITMAP CONVERSION COUNT     |        |    10 |    20 |     1   (0)| 00:00:01 |
|* 3 |    BITMAP INDEX FAST FULL SCAN| SEXIDX |       |       |            |          |
Predicate Information (identified by operation id):
   3 - filter("SEX"='F')
SQL> set autot off
SQL> alter session set events '10046 trace name context forever, level 12';
Session altered.
SQL> select count(*) from blah where sex = 'F';
COUNT(*)
        10
SQL> disconn
Disconnected from Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining optionsand here is relevant section from tkprofed trace file assuring that bitmap index fast full scan really was performed.
select count(*)
from
blah where sex = 'F'
call     count       cpu    elapsed       disk      query    current        rows
Parse        1      0.00       0.02          0          0          0           0
Execute      1      0.00       0.03          0          0          0           0
Fetch        2      0.00       0.00          0          3          0           1
total        4      0.00       0.05          0          3          0           1
Misses in library cache during parse: 1
Optimizer mode: ALL_ROWS
Parsing user id: 60
Rows     Row Source Operation
      1 SORT AGGREGATE (cr=3 pr=0 pw=0 time=74 us)
      1   BITMAP CONVERSION COUNT (cr=3 pr=0 pw=0 time=55 us)
      1    BITMAP INDEX FAST FULL SCAN SEXIDX (cr=3 pr=0 pw=0 time=43 us)(object id 98446)Gints Plivna
http://www.gplivna.eu

Hello Gints. I've reported this to the writer responsible for the Performance Tuning Guide. One of us will get back to you with the resolution.
Regards,
Diana

Performance Tuning on PL/sql

Dear all,
I am not sure whether I am right to post this enquiry here, please correct me if I am wrong.
I have a sql stmt that run for a long time and caused a error of 'out of temp sapce' in oracle server. How can I tune my sql for better performance using command 'EXPLAIN PLAN'? How could I know the details information for those columns in the table 'PLAN_TABLE'?
Best Regards,
Marius

Read the "Database Performance Tuning Guide and Reference" for your version of Oracle (available online, right here).
Richard

Planning to start the performance tuning but....

Friends,
Database OS: RHEL AS 3.0
Database: Oracle Release 9.2.0.4.0
Number of Tables: 503
TableSpace size - 1.8GB out of 3GB
Max.Records in a Table - 1 Million and its increasing..
Our DB Optimizer mode is - CHOOSE (is it RBO?)
We are not using enterprise manager and not installed any tuning scripts like statspack etc....
Currently we are taking user managed backup without any problem so we are continuing the same from 2004 onwards.
Now we want want to tune our database.(We have never tuned our database)
We would like to change our optimizer from RBO to CBO.
Can anybody tell me the first step for the performance tuning?
Please dont suggest me oracle doc im already studying.....its taking time....
In the mean time......
Step 1: Can i Analyze the table or dbms_stat package?
We have not at all used the analyze or dbms_stat. So can i start with any of the above or do u have any other suggestions for the 1st step?
Thanks

our manager feels that if we tune our db the performance will be more than compared to the current one.you have a mystique manager then, ask him what kind of "feelings" does he have about my database ;) there is no place for feelings in this game, this is life cycle to be successful ; testing->reporting->analyzing->take nedded actions->re-testing->reporting->analyzing..
so while you are surely reading the documentation;
Oracle9i Database Performance Planning Release 2 (9.2)
http://download.oracle.com/docs/cd/B10501_01/server.920/a96532/toc.htm
Oracle9i Database Performance Tuning Guide and Reference Release 2 (9.2)
http://download.oracle.com/docs/cd/B10501_01/server.920/a96533/toc.htm
first thing you have to do is to setup an appropriate test environment with same os-oracle releases, parameters;
-- some of them to check
SELECT NAME, VALUE
FROM v$system_parameter a
WHERE a.NAME IN
       ('compatible', 'optimizer_features_enable',
        'optimizer_mode', 'pga_aggregate_target', 'workarea_size_policy',
        'db_file_multiblock_read_count', .. )and of course schema set and data amount. Then you run your application on load and take statspack snapshots and do the same after collecting statistics;
-- customize for your configuration, schema level object statistics
exec dbms_stats.gather_schema_stats( ownname =>'YOUR_SCHEMA', degree=>16, options=>'GATHER AUTO', estimate_percent=>dbms_stats.auto_sample_size, cascade=>TRUE, method_opt=>'FOR ALL COLUMNS SIZE AUTO', granularity=>'ALL');
-- check your system stats, with sys account
SELECT pname, pval1 FROM sys.aux_stats$ WHERE sname = 'SYSSTATS_MAIN';after you have the base report and the report after change compare the top 5 waits, the top queries which have dramatic logical I/O changes etc. At this point you go into session based tuning in order to understand why a specific query performs worser with CBO compared to RBO. You need to be able to create and read execution plans and i/o statistics at least. Here are some quick introductions;
http://www.bhatipoglu.com/entry/17/oracle-performance-analysis-tracing-and-performance-evaluation
http://psoug.org/reference/explain_plan.html
http://coskan.wordpress.com/2007/03/04/viewing-explain-plan/
and last words again goes to your manager; how does he "feel" about a 10gR2 migration? With Grid Control, AWR, ADDM and ASH performance tuning evolved a lot. Important note here, after 10g RBO is dead(unsupported).
Best Regards,
H.Tonguç YILMAZ
http://tonguc.yilmaz.googlepages.com/
Message was edited by:
TongucY

Performance Tuning For 11g Database

I've heard some Oracle DBA's suggest / recommend that specific parameters be tuned in the O.S. for using Linux as a dedicated Oracle 11g database server. I'm guess those parameters vary greatly based on utilization, hardware, and various other factors. I just wanted to ask if there are some soft or safe performance adjustments I can make which regardless of other various factors that are unknown would most likely benefit and or improve database performance?
Here is what I know:
- OS = RHEL 6.2 or OEL 6.2 64-bit
- RAM = 4 GB
- x2 Quad Core Xeon CPU's
Thanks for shedding any light on this for me...

>
I've heard some Oracle DBA's suggest / recommend that specific parameters be tuned in the O.S. for using Linux as a dedicated Oracle 11g database server. I'm guess those parameters vary greatly based on utilization, hardware, and various other factors. I just wanted to ask if there are some soft or safe performance adjustments I can make which regardless of other various factors that are unknown would most likely benefit and or improve database performance?
>
ALWAYS read and follow the instructions provided by Oracle in the installation guide. It discusses the very issue you mention.
http://docs.oracle.com/cd/E11882_01/install.112/e24321.pdf
There is even a section for 'Configuring Kernel Parameters for Linux'
After you read the installation guide and evaluate your own installation environment if you have any specific questions then post them. And if you intend to 'guess those parameters vary greatly based on utilization, hardware, and various other factors' then it should be obvious that you need to provide information on 'utilization, hardware, and various other factors' or we won't be able to help you with your specific use case.

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

Database performance tuning Question

Similar Messages

Maybe you are looking for