On Aug 20, 2013, at 12:51 PM, Ed Leafe <e...@openstack.org> wrote: > On Aug 20, 2013, at 2:33 PM, Chris Behrens <cbehr...@codestud.com> > wrote: > >> For instances table, we want to make sure 'uuid' is unique. But we can't >> put a unique constraint on that alone. If that instance gets deleted.. we >> should be able to create another entry with the same uuid without a problem. >> So we need a unique constraint on uuid+deleted. But if 'deleted' is only 0 >> or 1… we can only have 1 entry deleted and 1 entry not deleted. Using >> deleted=`id` to mark deletion solves that problem. You could use >> deleted_at… but 2 creates and deletes within the same second would not work. >> :) > > This creates another problem if you ever need to delete this second instance, > because now you have two with the same uuid and the same deleted status.
Not with the setting of 'deleted' to the row's `id` on delete… since `id` is unique. - Chris _______________________________________________ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
