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Re: why do you apply undo before redo?

From: Ryan <rgaffuri_at_cox.net>
Date: Mon, 19 Apr 2004 20:24:39 -0400
Message-ID: <87_gc.5258$uF3.4934@lakeread04>


I still do not understand why its better to do undo before redo. I do not see how you can have an inconsistent state the other way. I know Oracle does it that way.

I'm at a loss for the theory. Does anyone know more? "Jan Hidders" <jan.hidders_at_REMOVETHIS.pandora.be> wrote in message news:EJXgc.78458$NI6.5303414_at_phobos.telenet-ops.be...
> Ryan wrote:
> > "Jan Hidders" <jan.hidders_at_REMOVETHIS.pandora.be> wrote in message
> > news:HFDgc.77172$4W5.5180553_at_phobos.telenet-ops.be...
> >>
> >>No, I'm not. In the example the transaction in the UNDO list did not yet
> >>commit, and the transaction in the REDO list did. Does the book not
> >>explain what the REDO and the UNDO list are and how they are
constructed?
> >
> >
> > I know what undo and redo are. How is it possible to commit redo and not
> > undo?
>
> With "did not yet commit" I meant "did not yet commit before the crash".
>
> -- Jan Hidders
Received on Mon Apr 19 2004 - 19:24:39 CDT

Original text of this message

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