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Rollback per transaction % too high and a lot db file sequential reads [message #271412]

Mon, 01 October 2007 10:59

thorin666
Messages: 144
Registered: March 2007

Senior Member

Hi
i have performance problems and i see in statspack that rollback per transaction % is at 99.90 (and that number must be near "0") i think
Is this a parameter problem or it's an aplication problem?
how can i fix it?

in other side of the statspack report i see that in the top5 wait events i have
db file sequential read 1.6M waits (in 15 minutes aprox)
but i cant find the cause
thnx in advance

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Re: Rollback per transaction % too high and a lot db file sequential reads [message #271419 is a reply to message #271412]

Mon, 01 October 2007 11:19

Michel Cadot
Messages: 68704
Registered: March 2007
Location: Nanterre, France, http://...

Senior Member
Account Moderator

Quote:

that rollback per transaction % is at 99.90 {...] Is this a parameter problem or it's an aplication problem?

It is an application issue. Likely a Sybase/MS SQL Server application stupidely ported in Oracle.
It is not a serious problem if there is nothing to rollback.

Analyze the wait events. If it is IO, analyze the SQL.

Regards
Michel

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Re: Rollback per transaction % too high and a lot db file sequential reads [message #271423 is a reply to message #271419]

Mon, 01 October 2007 11:22

thorin666
Messages: 144
Registered: March 2007

Senior Member

i am not using mssql or sybase
it's true that i am using a 3rd part program
i must to check the io reads sqls (from statspack?)

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Re: Rollback per transaction % too high and a lot db file sequential reads [message #271442 is a reply to message #271423]

Mon, 01 October 2007 12:21

Michel Cadot
Messages: 68704
Registered: March 2007
Location: Nanterre, France, http://...

Senior Member
Account Moderator

I didn't say you are using these ones. I said it is likely an Sybase-like application.
Maybe it is an Oracle application developped by a Sybase programmer.

For the rest read How to Identify Performance Problem and Bottleneck.

Regards
Michel

[Updated on: Mon, 01 October 2007 12:23]

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Re: Rollback per transaction % too high and a lot db file sequential reads [message #271519 is a reply to message #271412]

Mon, 01 October 2007 17:02

OracleDisected
Messages: 25
Registered: September 2007
Location: Mexico

Junior Member

Hi,

The db file sequential read wait is related to index access.

If this is an overall figure is not that bad, cause it adds the time spent waiting for IO to complet on ALL sessions accesing indexes.

If that figure corresponds to one session or sentence, then you may check the indexes involved (if exist) or even a table-full (if don't exist).

Regards
Ignacio

[Edit MC: url to poster blog removed. We don't care about your blog in this post. If you have an answer on your site, post a link to this answer. If you don't, post your blog url in Marketplace]

[Updated on: Thu, 11 October 2007 12:40] by Moderator

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