As you mentioned I keep getting the same error no matter what i do . I tried already doing offline drop of undo datafile on mount while setting _*offline_rollback*_segments _*corrupted_rollback*_segments _*allow_resetlogs*_corruption even the oracle support suggest me to go ahead and copy a full backup . so I will take it as a learning and go back copy files. thanks everybody. -Prasad On Jan 18, 2008 1:00 PM, Jeremiah Wilton <jeremiah@xxxxxxxxxxx> wrote: > Prasad, > > The error you are getting from open is that the UNDO tablespace datafiles > are missing. Specifying _corrupted_rollback_segments will not solve that > problem. If you would like to move on to the *next* error you are going to > receive, then you can re-create the controlfile with the UNDO datafiles > removed, or you can OFFLINE DROP them from MOUNT mode. > > Notably, the method of saving time/space you devised is simply invalid. > You > need undo in order to create a consistent database. You can technically > open it without UNDO, but the result will range from inconsistent in the > best case, to constantly crashing in the worst. > > For those performing real recoveries of production data, I think this > group > is a great place to learn about extraordinary recovery methods, such as > how > to allow resetlogs/read only corruption, specify corrupted rollback > segments, and artificially advance the SCN. But for those like you who > are > willfully persisting in a flawed approach, the desire to help, at least on > my part, is greatly reduced. > > Please just go back and get a copy of the UNDO tablespace which at 16G is > really not that big. It doesn't matter if it takes 20 hours to make the > copy, as long as you can bring it all consistent with archivelogs. As > with > others, I recommend taking a more conventional approach to this project. > I > don't believe you will be providing your clients with a test system that > is > consistent with professional standards if you continue on your current > path. > > Regards, > > Jeremiah Wilton > ORA-600 Consulting > > > Prasad wrote: > > > Yes, it shows correctly printed in the alert log . but when I try to do > show parameter it do not show . does > > that mean it is effective on the background? but if it is effective > then > when I try to open in resetlogs it > > should not complain about undotbs . but right now it complains. > > >