Performance problems ORACLE after change PA-RISC to Itanium system !!

[Former Member]

Hi Gurus !!!

We have change our production system from PA-RISC to Itanium and we have a high bad perfomance in database. We are checking parameter, but at this time we have not found any error.

Oracle Database 10.2.0.4 both systems.

In ST04 now we have this "bad" values

- Buffer Quality 93 %

- Reads / user Calls -> 64,7 (this value normally in PA-RISC was < 7 !!!! (Compared with other day like today !!!)

Please any help !!!

Thanks in advance !!!

[stefan_koehler]

Hello Xavier,

we have a high bad perfomance in database

What is bad? Is it a particuarl query? Is it slower overall queries?

- Buffer Quality 93 %
- Reads / user Calls -> 64,7 

Personally i don't rely on Buffer Quality, but the "Reads per User Call" is an indicator for some expensive SQL statements.

Refering to the following SAP documentation it should be less than 30 (http://help.sap.com/saphelp_40b/helpdata/pt/c4/3a7223505211d189550000e829fbbd/content.htm).

Goto ST04old or DBACOCKPIT and analyze the shared pool for expensive SQLs (check the columns reads/exec and bgets/row).

Regards

Stefan

[TomCenens]

Hello Xavier

Make sure you also have the correct recommended parameter settings, can make a serious difference:

Note 830576 - Parameter recommendations for Oracle 10g

Concerning system stats, dictionary stats I would recommend that you implement BR*Tools 710 with which you can set additional parameters in init<SID>.ora file to automatically run system and dictionary stats every X days with your regular statistics calculation run.

After you "change". If you have a new database keep in mind buffers need to also be filled up before you have good % values.

Kind regards

Tom

[Former Member]

How did you migrate? Just copy the database files? I hope you did a new install of the database software (because it is possible to run the PA-Risc binaries on IA64).

As a first action, you should generate new database stats, especially system and dictionary stats:

brconnect -c -u / -f stats -t system_stats
brconnect -c -u / -f stats -t oradict_stats
brconnect -c -u / -f stats -t all -f collect -p <degree>

Second you should investigate the costly SQL statements (make sure your db_cache_size is at least the same size than before).

Cheers Michael