Comment 4 for bug 1482416

To clarify, nova is not supporting drops on tables or columns:

https://review.openstack.org/#/c/197349/

sqlite doesn't support alter:

http://www.sqlite.org/lang_altertable.html

So you have to drop and recreate things with sqlite to fake it out, that's what sqlalchemy-migrate does with foreign key constraints and unique constraints, e.g. https://review.openstack.org/#/c/157878/.

So if you needed to support a column alter in nova and the failure is with sqlite, then fix sqlalchemy-migrate.