! Name truncation warning

- ON UPDATE clause in generated schema

  Would be nice to be able to specify this similar to on_delete.

- load_value() that returns object by value, similar to query_value()

  That would be both the database class function as well as the query
  result iterator function. The latter would be especially useful with
  views.

  Somewhat related: it could be that for views it is better not to
  dynamically allocate the instance when we do something like i->count.

- Mass UPDATE

  This could be very useful in data migration code. In fact, need to
  add an example in the manual when this is supported.

! Diagnose lack of default ctor if object used in relationship

  Got two questions on the mailing list about that in one week. Maybe
  always diagnose lack of public ctor? Maybe with a warning if no
  relationship? The no_ctor pragma like no_id?