Re: why do you apply undo before redo?
Date: Sun, 18 Apr 2004 12:25:12 GMT
> I'm reading a generic database textbook and it states that when databases
> are recovering undo is applied before redo.
Any specific reason why you would like the title of the book to remain a secret? :-)
Because some of the operations of the transactions of the UNDO list might conflict with those in the REDO list. So if you did the undo-phase last you might be erasing the result of some operations that you first did in the redo-phase.
- Jan Hidders