About database performance

I annalyze my database(oracle 8.04)using db tools.the following is report of results.
1: redo buffer copy misses ratio is 0.105%
you are having redo latch contention that
may cause performance reduction.
2. recursive calls ratio is 3.1%
recursive calls ratio is usually
between,7.0-10.0 for tuned production
system ,10-14 for tuned development
system.
3. high number of i/o operations:file
gygb05.dbf -17.9% gygb04.dbf -64.4%.
what is the meaning? why?
what will i do performance?
do you help me?
null

1. Adjust the buffer
2. Re-locate the tables , indexes that are mostly used to another drive
<BLOCKQUOTE><font size="1" face="Verdana, Arial, Helvetica">quote:</font><HR>Originally posted by sunzhaochang sunzhaochang ([email protected]):
I annalyze my database(oracle 8.04)using db tools.the following is report of results.
1: redo buffer copy misses ratio is 0.105%
you are having redo latch contention that
may cause performance reduction.
2. recursive calls ratio is 3.1%
recursive calls ratio is usually
between,7.0-10.0 for tuned production
system ,10-14 for tuned development
system.
3. high number of i/o operations:file
gygb05.dbf -17.9% gygb04.dbf -64.4%.
what is the meaning? why?
what will i do performance?
do you help me?<HR></BLOCKQUOTE>
null

Similar Messages

Oracle Database Performance With Semantic

Hello,
Is there a Developer's Guide for Semantic that specifically talks about database performance with the Semantic network/tables/indexes? We are having issues with performance the larger the semantic network becomes.
Any help or pointers would be appriciated.
Thanks
-MichaelB

Matt,
Thanks for your response. Here are the answers to the questions about our setup/environment.
1) Are you querying multiple models and/or a model + entailment? If so, are you using a virtual model and using the ALLOW_DUP=T query option?
A single model, no entailments. We attempted to use multiple models, and a virtual model (with ALLOW_DUP=T), however the UNION ALL in the explain plan made the query duration unacceptable.
2) Are you using named graphs?
No named graphs.
3) How many triples are you querying?
Approximately 85 million.
4) What semantic network and/or datatype indexes have been created?
We have PCSGM, PSCGM, PSCM, PCSM, CPSM, and SCM.
5) What is your hardware setup (number and type of disks, RAM, processor, etc.)?
We are running the 11.2.0.3 database on a Sun Solaris T2000, we have ASM managing our disks from RAID5, I believe currently we have two Disk Groups with the indexes in one and the data tables in the other. We have 32 GB of memory, and 32 CPUs. However, it is not the only thing running on the machine.
6) How much memory have you allocated to the database (pga, sga, memory_target, etc.)?
We have the memory_target set to 9GB, the db_cache_size set to 2GB, and the db_keep_cache_size set to 4.5GB. `pga_aggregate_target` is set to 0 (auto), as is `sga_target`.
(Since my initial request, we pinned the RDF_VALUE$ (~2.5GB) and C_PK_VID (~1.7GB) objects in the KEEP buffer cache, which drastically improved performance)
7) Are you using parallel query execution?
Yes, some of the more complex queries we run with the parallel hint set to 8.
8) Have you tried dynamic sampling?
Yes. We have ODS set to 3 for our more complex queries, we have not altered this much to see if there is a performance gained by changing this value.
Thanks again,
-Michael

How about a separate forum Database-Performance

hi friends/Moderators,
I had one thing to give feedback/suggestion to give , but didnt know of any link/place to put it.
So opening a new thread over it.
I see many new threads related to Database Performance, sql tuning, redo/undo ( and many other architecture related things which can impact the performance of the database).
How about a idea of having another forum Database-Performance like we have Database-General now?
Personally I would like to start replying to performance related questions so that apart from helping the OPs i learn more about performance issues which other people see or face outside of my workplace.
What do you guys say?
Cheers!

Kunwar wrote:
hi friends/Moderators,
I had one thing to give feedback/suggestion to give , but didnt know of any link/place to put it.
So opening a new thread over it.For such questions, please post them over the Community Discussions forum.
I see many new threads related to Database Performance, sql tuning, redo/undo ( and many other architecture related things which can impact the performance of the database).
How about a idea of having another forum Database-Performance like we have Database-General now?
Personally I would like to start replying to performance related questions so that apart from helping the OPs i learn more about performance issues which other people see or face outside of my workplace.
What do you guys say?
This was asked by me in 2008. Please have a read of the thread,
Can We Have a Perfomance Tuning Forum?
That said, it may break things even more. Don't take it personally but just take the example of this question. You are here from some time now and even then, you wrongly posted this question in a product forum even when there is already a non-technical, community feedback forum is in place. So may be people won't use a separate forum of Performance and will keep on posting the questions in different forums, just like what happens now too. And with every new forum added, the overhead would also increase (my guess) .
And another thing that comes to mind is that since the forums are already scheduled for a major upgrade in the mid-April , I doubt that such request would be fulfilled , at least right now because last time, when the upgrade of the forums happened, it wasn't a smooth one and the focus of the OTN team would be surely to make sure that the history won't repeat itself.
Just my 2 cents.
Aman....

Regarding Database Performance

Hi All,
I have installed *10gR2 on RHEL4 (4GB -- RAM, space is enough)*. One application (oracle ucm) is running on that. Its contains apache and content server. After 2-3 weeks, developers were saying taking long time for opening url. So done gather database statistics (after that daily gathering db stats using scheduler). After that, it was working fine. Again after week they are having the prob. They are doing lot of dml on db. Checked in os level using top command. But oracle ( installed entire application as oracle) user is not consuming that much memory. set pga_aggregate_target to about 500M. Sga (sga_max_size --- 950M) is auto tuning. db is of size 8GB. workarea_policy_size is auto.
Please suggest any solutions for improving database performance.
Thanks,
Manikandan.

daily gathering db stats using scheduler)Done by default on V10+
Please suggest any solutions for improving database performance.Ready, Fire, Aim!
Is any OS resource the bottleneck; CPU, RAM, IO, network?
During slow period what is reported by AWR?
Please read these:
When your query takes too long
When your query takes too long ...
How to Post a SQL statement tuning request
HOW TO: Post a SQL statement tuning request - template posting
Edited by: sb92075 on Jul 27, 2010 10:01 AM

Database performance

Can anyone help me? I just anted to know which are best and
precise sites on internet where I can find info about Oracle 8i
database performance monitoring,correction,best practises and
prevention. Many times our database performance goes down and
need to trouble shoot and correct the problems
Thanks
sandeep

Hi sue..
please send the papers to me also..my mail id [email protected]
bye bye
subbu
The Oracle Performance and Tuning class is very good at least
when I took it around 2 years ago.
Oracle Performance Tuning by Mark Curry and Peter Corrigan is
good but is probably too deep for someone new in Oracle. (It's
too deep for me most of the time since I've worked with Oracle
for 2.5 years now)
I could also send you a paper that gives a fairly good
explanation on use of V$SESSION_WAIT, V$SESSION_EVENT, and
V$SYSTEM_WAIT. V$SESSION_WAIT tells you what application is
wating and what is the event wait occuring.
Let me know if you want it.

Database performance side effects of huge inserts

All,
I know this might not be the right place to raise this question. Just thought any of you might have come across this in db programming.
I have a table in database in which there would be huge no. of insertions through out the day. The volume of insertions per day would be around 20000 rows. And there is no process other than this which would be querying this table.
My question is whether so many INSERTs on one table would affect in any way the performance of the whole database ?
Would this affect the response time of the processes working with other tables in the same database ?

My question is whether so many INSERTs on one tablewould affect in any way the performance of the whole
database ?
Would this affect the response time of the processesworking with other tables in the same database ?
Yeah since it's running on the same PC.
The volume of insertions per day would be around20000 rows. And there is
no process other than this which would be queryingthis table.
But 20000 rows is a very small insert number for
database, so you needn't to consider too much about
performance. If you wish to insert quicker, you
should use PreparedStatement to insert your rows, or
use batch insert.
One exception is that you'r inserting 20000 rows into
a very big table with many index expressions on that
table or imported/exported keys on other big tables.
That will be slower.Well this table wont have any foreign keys on any big table...
though the table size would be huge... would gross upto 1 gb data in a month. I am not concerned about the performance of queries on this table at any stage.. but would continuous insertions... 10 INSRTS a sec in this table affect the performance of the rest of the tables in the db in any way

Database Performance Slow

Hi to all,
My database performance is suddenly going slow. My PGA Cahe hit percentage remain in 96%.
I will list out the findidngs I found...
Some tables were not analyzed since Dec2007. Some tables were never analyzed.
(Will the tables were analyzed the performance will be improved for this scenario)
PGA Allocated is 400MB. But till now the max pga allocated is 95MB since Instance started (11 Nov 08 - Instance started date).
(I persume we have Over allocated PGA can i reduce it to 200MB and increase the Shared pool and Buffer Cache 100MB each?)
Memory Configuration:
Buffer Cache: 504 MB
Shared Pool: 600 MB
Java Pool: 24MB
Large Pool: 24MB
SGA Max Size is: 1201.72 MB
PGA Aggregate is: 400 MB
My Database resided in Windows 2003 Server Standard Edition with 4GB of RAM.
Please give me suggestions.
Thanks and Regards,
Vijayaraghavan K

Vijayaraghavan Krishnan wrote:
My database performance is suddenly going slow. My PGA Cahe hit percentage remain in 96%.
Some tables were not analyzed since Dec2007. Some tables were never analyzed.
PGA Allocated is 400MB. But till now the max pga allocated is 95MB since Instance started (11 Nov 08 - Instance started date).
(I persume we have Over allocated PGA can i reduce it to 200MB and increase the Shared pool and Buffer Cache 100MB each?)
You are in an awkward situtation - your database is behaving badly, but it has been in an unhealthy state for a very long time, and any "simple" change you make to address the performance could have unpredictable side effects.
At this moment you have to think at two levels - tactical and strategic.
Tactical - is there anything you can do in the short term to address the immediate problem.
Strategic - what is the longer-term plan to sort out the state of the database.
Strategically, you should be heading for a database with correct indexing, representative data statistics, optimium resource allocation, minimum hacking in the parameter file, and (probably) implementation of "system statistics".
Tactically, you need to find out which queries (old or new) have suddenly introduced an extra work load, or whether there has been an increase in the number of end-users, or other tasks running on the machine.
For a quick and dirty approach you could start by checking v$sql every few minutes for recent SQL that might be expensive; or run checks for SQL that has executed a very large number of times, or has used a lot of CPU, or has done a lot of disk I/O or buffer gets.
You could also install statspack and start taking snapshots hourly at level 7, then run off reports covering intervals when the system is slow - again a quick check would be to look at the "SQL ordered by .." sections of the report to the expensive SQL.
If you are lucky, there will be a few nasty SQL statements that you can identify as responsible for most of your resource usage - then you can decide what to do about them
Regarding pga_aggregate_target: this is a value that is available for sharing across all processes; from the name you've used, I think you may be looking at a figure for a single specific process - so I wouldn't reduce the pga_aggregate_target just yet.
If you want to post a statspack report to the forum, we may be able to make a few further suggestions. (Use the "code" tags - in curly brackets { } to make the report readable in a fixed fontRegards
Jonathan Lewis
http://jonathanlewis.wordpress.com
http://www.jlcomp.demon.co.uk
"The temptation to form premature theories upon insufficient data is the bane of our profession."
Sherlock Holmes (Sir Arthur Conan Doyle) in "The Valley of Fear".

Database performance issue (8.1.7.0)

Hi,
We are having tablespace "payin" in our database (8.1.7.0) .
This tablespace is the main Tablespace of our database which is dictionary managed and heavily accessed by the user SQL statements.
Now we are facing the database performance issue during the peak time (i.e. at the month end) when no. of users use to run the no. of large reports.
We have also increased the SGA sufficiently on the basis of RAM size.
This tablespace is heavily accessed for the reports.
Now my question is,
Is this performance issue is because the tablespace is "dictionary managed" instead of locally managed ?
because when i monitor the different sessions through OEM, the no. of hard parses is more for the connected users.
Actually the hard parses should be less.
In oracle 8.1.7.0 Can we convert dictionary managed tablespace to locally managed tablespace ?
by doing so will the problem will get somewhat resolve ? will it reduce the overhead on the dictionary tables and on the shared memory ?
If yes then how what is procedure to convert the tablespace from dictionary to locally managed ?
With Regards

If your end users are just running reports against this tablespace, I don't think that the tablespace management (LM/DM) matters here. You should be concerned more about the TEMP tablespace (for heavy sort operations) and your shared pool size (as you have seen hard parses go up).
As already stated, get statspack running and also try tracing user sessions with wait events. Might give you more clues.

Does too many extents afftect database performance?

Hi gurus
There are some tablespaces created with "UNIFORM SIZE 1M" which should be created "SYSTEM" . The database version is 10g. I worry about that too much extents will affect the database performance even
availability cause extent management overhead. Do i need to recreate these tablespace with "SYSTEM" allocation type or just do nothing? Thank u for your reply!!
Edited by: KevinMao on Apr 12, 2009 8:48 PM

"SYSTEM" is for Tablespaces created with AUTOALLOCATE. Here you would have extents sizes beginning at 64K and then growing to 1M, 8M and 64M.
With "UNIFORM 1M" all your extents are 1M in size. If you have tables/indexes/partitions growing into the tens of GBs in size, you would have extent counts of tens of thousands. That, in itself, is not an issue.
"extent management overhead" that you refer to is actually reduced from DMT to LMT. Within LMT, the difference between "UNIFORM 1M" and "AUTOALLOCATE" may not be noticeable unless you have a particular patten of a very large number of DROP and TRUNCATEs being executed frequently. In that case, assuming that such DROP and TRUNCATEs are for small "temporary" tables, "UNIFORM 1M" may actually be better than AUTOALOCATE, except that you would be "wasting" some disk space (as the former would use 1M extents while the latter would use 64K extents for the first MB).
If you think of "AUTOALLOCATE"s 8M and 64M extents for very large tables, you might actually be better of using UNIFORM 32M or UNIFORM 64M for specific tablespaces and tables. Just be careful not to put relatively small tables into such tablespaces !
Edited by: Hemant K Chitale on Apr 13, 2009 11:58 AM

Question about Databases on a distributed environment...

Hi,
I have quick question. We have production in a distributed environment as follows
(a) SQL server, EPMA, and Calc Manager
(b) Workspace, and Shared Services
(c) Essbase
(d) Planning
Now we have multiple databases for each hyperion service i.e.
(1) HSS (using for hyperion shared service)
(2) BIPLUS (Using for workspace)
(3) AAS (Using for Essbase Administrator Services)
(4) CALCMGR (Using for calculation manager)
(5) EPMA (Using for EPMA)
(6) ERPI (Using for ERP Integrator)
(7) PLANSYS (Using for Planning)
Now, my question is ....is it necessary that we have that multiple database in a distributed environment or we can have one database for everything? What is main objective for creating databases for each application?
Please share your best knowledge and give me positive and negative about multiple database and single database for hyperion...
Thanks to all...
Safi

I am going to be lazy and copy an extract from the install doc
For simplicity and ease of deployment, you can use one database repository for all products (with the exceptions noted below). When you configure multiple products at one time using EPM System Configurator, one database is configured for all selected products.
Caution!
To use a different database for each product, perform the “Configure Database” task separately for each product. In some cases you might want to configure separate databases for products. Consider performance, rollback procedures for a single application or product, and disaster recovery plans.
The following products and product components require unique databases:
Performance Management Architect interface data source
Extended Analytics for Financial Management and Extended Analytics for Strategic Finance
Planning – Each Planning application should have its own repository.
Performance Scorecard
FDM – Use an Oracle Database instance exclusively for FDM.
Data Relationship Management.
Cheers
John
http://john-goodwin.blogspot.com/

Where to learn about database tuning from?

Hello,
I need to learn more about database tuning - practical aspect. Are there any sites/services that could help me? I can't use production environment of course, I need to prepare my own ones (Oracle DBs on linux and windows too) and workload too. How to simulate workload from many users?
Thanks in advance for help
Aliq

How do you learn to paint? You can read every book on the subject, attend lectures by famous artists on paints and brushes and styles and what not..
None of this will turn you into an artist that can paint. Theory only goes that far.
And this is as true in performance tuning as in painting. You need to run into that brick wall called experience over and over again - and each time learn hard lessons that no theory can ever teach.
If performance tuning was that easy, we would have had fully automated tuning software in operating systems and database systems that could detect and fix all our performance woes on the fly.
Does not work like that.
Also, performance tuning is many times seen as an "after the fact" thing. Design the system. Code the software. Implement it. Then tune it.
Wrong. Also does not work like that.
Performance tuning begins at the very first workshop when brainstorming the basic design of the system. If performance and scalability are not part of that process, they cannot easily (if at all) be made to be part of the final system as a tuning exercise.
If I need to pass a single fundamental "uber-alles" principle for performance tuning - when dealing with it after the fact (as many of us do), then it is:
Identify The Problem
Do not confuse symptoms as the actual problem.
PS. Performance tuning is also many time (IMO) a situation where you have lost. Why? Because of if the code was designed and coded correctly, then there would not have been a performance issue. If the Oracle architecture was understood correctly, there would not be a problem. Which makes the advice by the other 2 posters so important. Understand Oracle. Understand how to design and code in Oracle. If done well, what is there left to performance tune?

Database performing Very slow - Lots of wait events

My database is on Oracle10g on Sun 5.10
The users are complaining about database is very slow.
I analyzed the indexes & later on rebuild them, hardly it has only 5% performance improvement.
http://i812.photobucket.com/albums/zz43/sadeel00/untitled1.jpg
http://i812.photobucket.com/albums/zz43/sadeel00/untitled2.jpg
ADDM has no recommendations.

Duplicate post - Database performing Very slow - Lots of wait events
Srini

Can archive log backup influence database performance?

Hi,
can archive log backup generally influence the database performance? I mean: users can view their query to go slowly during backup of archived redolog?

Are you asking about backing up the archived redo logs via rman or directly to tape or the actual archive process where Oracle backs the online redo to disk?
-- comments on archive process
Normally the redo log archiving process should have no noticable effect on database performance. About the only way for the process to have a noticable performance impact while it is running is if you store all your online redo logs on the same physical disk. You would also want the backup to be on a different physical disk.
Check your alert log to make sure you do not have error messages related to being unable to switch redo logs and checkpoint incomplete messages. These would be an indication that your online redo logs are defined too small and you are trying to cycle around before Oracle has finished archiving the older logs.
-- comments on archived redo log backup
Archived reodo logs should not be on the same disk as the database so using rman or an OS task to back these files up should not impact Oracle unless you server is itself near capacity and any additional task effects the server.
HTH -- Mark D Powell --

Database Performance for Newbies

Hello Forum,
the Database I have is now running for 1,5 years.
At the beginnig there where 90.000 login data per month. Now there are over 900.000 login data per month stored in a table.
I am now a little concerned about the performance, because I do not know anithing about it. Maybe the database crashes if 1.000.000 will bereached or what ever. I do not know.
I red few posts here in the forum about performance, but they are to complicated for me or I red the wrong ones.
Can somebody help me getting out some statistics or when the limit of the hardware resources will be reached or something?
I just did the following:
SELECT object_name, counter_name, cntr_value * 8/1024.0 AS SizeMB
FROM sys.dm_os_performance_counters
WHERE object_name = 'SQLServer:Buffer Manager'
counter_name IN ('Total pages', 'Target pages')
And got as result:
SQLServer:Buffer Manager Total pages 7943.0000
SQLServer:Buffer Manager Target pages 27565.8125
And if I go to the computer management console and look at performance it says:
Available MB: 21.759
Guranteed used Bytes (%): 16.9
So maxbe someone has some querys, tools or what ever for me, I can use and know if it looks good and when it will look bad.
Kind regards
Peter

You have not configured Max Server Memory and it would be good to set it such that you leave 4 to 8 GB for OS. If you dont have any other softwares/appilcation in your systems then 4 GB for OS and then set the rest 28 for SQL Server.
Check this article on How to set Max Server Memory -
http://technet.microsoft.com/en-us/library/ms191144(v=sql.105).aspx
You might need to do a performance stress test to understand if you can ramp up the number of concurrent users in the system. There is no easy way to predict it.
As far as monitoring goes, check this link I hope this is not really difficult to start with
http://www.sqlskills.com/blogs/jonathan/the-accidental-dba-day-21-of-30-essential-perfmon-counters/
http://www.brentozar.com/archive/2006/12/dba-101-using-perfmon-for-sql-performance-tuning/
You need to intially monitor the counters for few weeks so that you can create a base line as to how it performs. Then when you find any times the counters are way different from baseline you can start working on the find the root cause.
Now for database maintenance, If you are not doing any reindexing/updatestats etc I would suggest you to take a look at Ola Hallegrans scripts for this.
http://ola.hallengren.com/sql-server-index-and-statistics-maintenance.html
I am not sure if you are a dba or not, but you can start reading through this series to get more understanding in a gradual manner.
http://www.sqlskills.com/blogs/glenn/the-accidental-dba-day-1-of-30-hardware-selection-cpu-and-memory-considerations/
Regards, Ashwin Menon My Blog - http:\\sqllearnings.com

10g grid control. minimum DB privileges for database performance tab?

database -> performance tab -> log into database.
what are the minimum privileges needed for this? I normally use DBA privs. However, I need to give access to non-dbas. When I try to log in with their account, it says see the help. I have been hunting through the help, but can't find anything about this.

This article may be of use: http://dbastreet.com/blog/?tag=grid-control
If you "grant select any table" (Query tables, views, or mviews in any schema) to the role oem_monitor you get what you want. Maybe an overkill but thats what I can think of now.
Eric

About database performance

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