Originally posted by slimdave
Obvious question, but it has to be asked -- is there any differencein the nullability of columns between 8.1.7.4 and the other databases?

What average column lengths do you get for all these different scenarios?
The same table is imported on the 3 databases. avg_row_len is 350 on 10g and 9i, and 200/350/450 in 8.1.7 depending of the type of reorganisation of the columns.