Re: Deadlocks

From: Alex Fatkulin <afatkulin_at_gmail.com>
Date: Tue, 29 Sep 2009 15:22:21 -0400
Message-ID: <49d668000909291222l52cf3832s93d8628467813f7d_at_mail.gmail.com>

"The two sessions involved in the deadlocks are staying locked for over 24 hours. "

The sessions may stay blocked for 24h because it is not a deadlock yet.

"The Oracle documentation states that Oracle will detect the deadlock and will automatically resolve it by rolling back the transaction that detected the deadlock..."

I'm not sure where this came from but this is not how deadlock resolution works. What's getting rolled back is the statement which caused a deadlock, not the transaction. This called a statement-level rollback.

On Tue, Sep 29, 2009 at 3:06 PM, Julio Aguilar-Chang <jachang_at_lanl.gov> wrote:
> Hello:
> I have an Oracle 10.2.0.4 database running on Windows Server 2003.
>  Deadlocks are being reported in the alert log.  These deadlocks are being
> generated by a 3rd party application.  The two sessions involved in the
> deadlocks are staying locked for over 24 hours.  The Oracle documentation
> states that Oracle will detect the deadlock and will automatically resolve
> it by rolling back the transaction that detected the deadlock, thereby
> allowing the first transaction to complete.
>
> Even though my database is detecting the deadlock, it is not automatically
> rolling back the blocked transaction.  I'm having to do that manually.
>
> Has anyone experienced this behavior of the database not automatically
> resolving the deadlock?
> I, of course, have no access to the 3rd party app. code to see what types of
> explicit locks are being called, nor can I change the code even if I find
> out the faulty logic in the code.
>
> --
>
> *****************************************
> Julio Aguilar-Chang
> Los Alamos National Laboratory
> jachang_at_lanl.gov
> *****************************************
>
> --
> http://www.freelists.org/webpage/oracle-l
>
>
>

-- 
Alex Fatkulin,
http://afatkulin.blogspot.com
http://www.linkedin.com/in/alexfatkulin
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Received on Tue Sep 29 2009 - 14:22:21 CDT