On 28/03/12 17:20, Mark W. Farnham wrote: > Excellent summary Hans. The only thing I would add is the answer to the OP's > unstated question that I suspect is lurking: > .... If anyone wants to know how redo and/or undo work in an Oracle database, might I recommend Jonathan Lewis' excellent book on the matter Oracle Core Essentials. I read it on my eReader on holiday recently and my wife had no idea that I wasn't reading a "boys own adventure book" while sitting in the shade! You have to love eReaders! Cheers, Norm. -- Norman Dunbar Dunbar IT Consultants Ltd Registered address: Thorpe House 61 Richardshaw Lane Pudsey West Yorkshire United Kingdom LS28 7EL Company Number: 05132767 -- //www.freelists.org/webpage/oracle-l