Comment 4 for bug 981263

I agree that we need access to deleted instance types internally (within Nova), but I don't want to expose them through the public API. flavor_id is designed to be reused, while instance_type_id is the autoincrement unique id used internally. We do have a uniqueness requirement on flavor_id when deleted=0, but other than that it shouldnt matter.

Ideally we would treat flavors totally differently and simply apply the resources to an instance at boot, rather than preserving the tie to a separate table. Our current approach is very fragile and cumbersome.