strict constrain for the creation of db tables and columns

[Vincent Hou]

Some columns should be defined nullable=False，since they are unique in the table. For example, address in virtual_interfaces, host in aggregate_hosts, name in aggregates, etc. MySQL is ok, but databases with more strict column creation can yield errors, if it is not strictly defined.
Due to the same reason, method register_models in nova/db/sqlalchemy/models.py does not work for MYSQL. uuid in instance must be define unique and not null.

[Thierry Carrez (ttx)]

Looks like you're not working on that anymore. Please set back to InProgress and reassign to you if you're working on proposing a change for merging.

[Joe Gordon (jogo)]

Is this still valid, this bug is fairly old and many things have changed since then.

[Matt Riedemann (mriedem)]

This is being worked by blueprint enforce-unique-instance-uuid-in-db:

https://blueprints.launchpad.net/nova/+spec/enforce-unique-instance-uuid-in-db

https://review.openstack.org/#/c/97946/

I'm going to track this bug against that blueprint and invalidate this.