Re: Any tools/scripts for finding underlying cause of concurrency?
From: <johnbhurley_at_sbcglobal.net>
Date: Sun, 8 Mar 2009 13:21:38 -0700 (PDT)
Message-ID: <39c41621-8ef0-4bb0-b5ab-d81fdbf33691_at_x13g2000yqf.googlegroups.com>
On Mar 8, 11:56 am, vm22 <vivekmarw..._at_gmail.com> wrote:
> We have been having concurrency issues for the past week but have
> managed to resolve it (the underlying cause of it was a bug). One
> thing that I wanted to know is that if there are any tools or scripts
> out there to tell us immediately the cause of the concurrency?
>
> All we saw in OEM was a couple of statements which were the Top SQL as
> well as a session that was blocking and several being blocked. We
> could not see the underlying SQL that was causing it. Eventually, the
> issue was the UNDO segments being released from a huge transaction -
> thereby causing the concurrency.
>
> Any help is appreciated.
>
> Regards,
> Vivek
Date: Sun, 8 Mar 2009 13:21:38 -0700 (PDT)
Message-ID: <39c41621-8ef0-4bb0-b5ab-d81fdbf33691_at_x13g2000yqf.googlegroups.com>
On Mar 8, 11:56 am, vm22 <vivekmarw..._at_gmail.com> wrote:
> We have been having concurrency issues for the past week but have
> managed to resolve it (the underlying cause of it was a bug). One
> thing that I wanted to know is that if there are any tools or scripts
> out there to tell us immediately the cause of the concurrency?
>
> All we saw in OEM was a couple of statements which were the Top SQL as
> well as a session that was blocking and several being blocked. We
> could not see the underlying SQL that was causing it. Eventually, the
> issue was the UNDO segments being released from a huge transaction -
> thereby causing the concurrency.
>
> Any help is appreciated.
>
> Regards,
> Vivek
Are you working with your DBA on this?
Not quite sure if you are understanding the concepts correctly.
Oracle uses locking mechanisms to manage concurrency. Most of the time it is transactions involved that lock resources that other transactions are trying to access. At times there can be some funky things with space in blocks not only data and index but perhaps other types of blocks. Received on Sun Mar 08 2009 - 15:21:38 CDT