Erm right; I have set undoretention to 1 second; and I still seem to be running out of disk space - my undo tablespace is 10gb+. I am only updating 100m rows, and it can't be using 10gb to retain 1 sec of undo info? can it?!

How can i tell oracle that the changes i have made are ok and i definatly want them (so it can junk the undo info)?