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Rollback per transaction % too high and a lot db file sequential reads [message #271412] Mon, 01 October 2007 10:59 Go to next message
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

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 Go to previous messageGo to next message
Michel Cadot
Messages: 64152
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
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 Go to previous messageGo to next message
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?)
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 Go to previous messageGo to next message
Michel Cadot
Messages: 64152
Registered: March 2007
Location: Nanterre, France, http://...
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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 Go to previous message
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

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

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