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statspack [message #172476] Tue, 16 May 2006 13:48 Go to next message
rkl1
Messages: 97
Registered: June 2005
Member
Dear All:I have a few questions on statspack and any suggestion and advice would be highly appreciated.

1.how many logical reads and physical reads/s would consider for an average load.

2. What should be a large redo size per second.

3.what should be the avg.read(ms) for datafile and avg buffer waits (ms) for individual data file.

4.Going down on the statspack report:for the Top 5 Timed events:
we may have db file scatter read, cpu time etc. It has four columns: event, waits, time (s) and %Total Ela Time. Is the %Total Ela Time refers to the elapsed time ie, the time duration between the 2 snapshots (say 60 minutes on which starts report is created). However calculating the % does not make it equal to the actual time elasped. I have seen some articles referring to the response time which is total of service time and wait time.

thanks.

Thanks.
Re: statspack [message #172493 is a reply to message #172476] Tue, 16 May 2006 19:47 Go to previous message
krystian.zieja
Messages: 12
Registered: May 2006
Location: Poland
Junior Member
1.how many logical reads and physical reads/s would consider for an average load.

Depends on the system

2. What should be a large redo size per second.

I would say redo size and it is dependent on the system

3.what should be the avg.read(ms) for datafile and avg buffer waits (ms) for individual data file.

Depends on the system

4.Going down on the statspack report:for the Top 5 Timed events:

Database is always waiting for something. Read on asktom.oracle.com about CPU wait time – there is brilliant description.

There is no average on database systems, each system is totally different. I think you should get several statspack reports and compare the results. In statspack reports you have also listed SQL Statements which caused most of buffer gets, if you have problems with wait db file scattered read I would advice you investigating this SQL statements maybe you can tune them.

Best Regards
Krystian Zieja / mob
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