| Performance of Oracle 9i in Unix machine (merged 3) [message #270658] |
Thu, 27 September 2007 13:47  |
oraprobs
Messages: 9
Registered: September 2007
Location: lowell
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Junior Member |
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hi,
I have upgraded oracle 8i machine to oracle 9i in an unix machine.After the upgradation the queries are taking much long time to execute.The query that used to take 20 secs in oracle 8i, is taking 10 mins to execute now.How might be the reason for this.Please help me.
thanks in advance,
Brad
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| Performance of Oracle 9i in Unix machine [message #270677 is a reply to message #270658] |
Thu, 27 September 2007 14:15  |
oraprobs
Messages: 9
Registered: September 2007
Location: lowell
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Junior Member |
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hi,
I have upgraded oracle 8i machine to oracle 9i in an unix machine.After the upgradation the queries are taking much long time to execute.The query that used to take 20 secs in oracle 8i, is taking 10 mins to execute now.How might be the reason for this?Please help me.
thanks in advance,
Brad
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| Oracle 9i in unix and Oracle 9i in Windows [message #270712 is a reply to message #270658] |
Thu, 27 September 2007 16:57 |
oraprobs
Messages: 9
Registered: September 2007
Location: lowell
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Junior Member |
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Is there any performance difference between Oracle 9i in unix and oracle 9i in windows.My application uses both oracle 8i and oracle 9i.Initially i had my application setup(inslatted in windows machine) with oracle 8i database installed in an unix machine.then i upgraded it to oracle 9i.My application has became very slow.I did the same in Windows i.e. I installed oracle 8i in windows machine,my application was running fine with it.then i upgrade the database to oracle 9i.now also my application is runinng fine.So why only the database performane degraded for upgrading the database in the unix machine?Please help me.
thanks in advance,
Brad
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| Re: Performance of Oracle 9i in Unix machine (merged 3) [message #271009 is a reply to message #270658] |
Fri, 28 September 2007 13:32 |
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BlackSwan
Messages: 26766
Registered: January 2009
Location: SoCal
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Senior Member |
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>This link doesn't work...
Which link does not work?
We are NOT mind readers!
If "tuning" was easy to do, it would be done automagically by a program.
1. Read Concepts manual.
2. Understand that most performance issues come from application issues.
For example, if some silly SQL reads an entire table to get a few rows,
you wil likely have a lot of unnecessary I/O that won't fill up the SGA.
3. Read the Performance manual.
4. Understand the optimizer. It can only use the information it is given.
If the statistics it uses are wrong, non-existent, or skewed in a manner the
optimizer doesn't know about, it can choose a silly plan for accessing the data.
Sometimes a full table scan is not silly.
5. Understand what plans are and how to use them to understand 4.
6. Understand what statspack can tell you.
7. Understand when, how and why to use tracing.
8. Understand what waits are and how to evaluate them.
9. Read and work through books and articles by Jonathan Lewis, Tom Kyte, and Cary Milsap.
10. Understand why rules of thumb can be a bad idea for improving the database of customers.
11. Understand that tools based strictly on Oracle can be a bit misleading from a systems
standpoint, and systems tools can be misleading from Oracle's viewpoint. Simply knowing
you have a lot of reads does not mean anything is wrong, after all, what is a database
going to be used for? A proper tuning methodology will figure out what critical
bottlenecks are, and what to do about them.
12. Understand the basics. For example, if you have sequential write-intensive
archive writing interfering with random reads and writes for undo and everything
else, thrashing a SAN cache, you probably have a configuration problem. If you
have multiple users accessing data, you need to understand how Oracle handles
the issues involved.
13. Create clear metrics for performance improvement.
14. Read Concepts manual.
15. Go to #1 above
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