Re: when client disconnect oracle server abnormally

From: Mark D Powell <>
Date: Thu, 22 Oct 2009 06:45:18 -0700 (PDT)
Message-ID: <>

On Oct 22, 12:20 am, karim <> wrote:
> hello to all.
> if i am working in a client side and suddenly lost the connection
> between me and oracle server, then what the server do to uncommitted
> statements? will the server make auto-commit or rollback.
> thanks.

If the front-end session suddenly loses its connection to Oracle what happens depends on what caused the connection loss to begin with and where the problem occurred: on the database side, in the network transport, either end OS, or in the front-end application itself, and on if Oracle recongizes that the front-end went away.

If Oracle recognises the abnormal termination then pmon will clean up the user Oracle background processing releasing locks and other resources held. If Oracle does not recognize the front-end loss then the user session Oracle background process becomes what is known as a runaway or dead session usually showing as waiting on a response/ request from the client.

There have been numerous thread on dead session detection. There are Oracle parameters that can be used to terminate these sessions automatically.

HTH -- Mark D Powell -- Received on Thu Oct 22 2009 - 08:45:18 CDT

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