Chris wrote:
> Hiroshi Inoue wrote:
>
> > When I used Oracle,I saw neither option of DROP
> > COLUMN feature. It seems to tell us that the
> > implementation isn't
> > that easy. It may not be a bad choise to give up DROP
> > COLUMN feature forever.
>
> Because it's not easy we shouldn't do it? I don't think so. The perfect
> solution is lazy updating of tuples but it requires versioning of
> meta-data and that requires a bit of work.
>
We could easily break the consistency of DB due to careless
implementations. Is "DROP COLUMN" valuable to walk on a
tightrope ? I would agree if "ADD COLUMN" needs to walk
on a tightrope.
Regards.
Hiroshi Inoue