Re: AW: [HACKERS] ALTER TABLE DROP COLUMN

[Hiroshi Inoue]

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. > > > However I would strongly object to 2x > > ADD COLUMN if such implementations are proposed. > > Not even 2x for ADD COLUMN DEFAULT ? Certainly it would need 2x. However is ADD COLUMN DEFAULT really needed ? I would do as follows. ADD COLUMN (without default) UPDATE .. SET new_column = new default ALTER TABLE ALTER COLUMN SET DEFAULT Regards. Hiroshi Inoue