per-relationship basis by supplying C<< cascade_update => 0 >> in the
relationship attributes.
-The cascaded operations are performed after the requested update,
-so if your database has a constraint on the relationship, it will
-have updated/updated the related records or raised an exception
-before DBIx::Class gets to perform the cascaded operation.
+This is not a RDMS style cascade update - it purely means that when
+an object has update called on it, all the related objects also
+have update called. It will not change foreign keys automatically -
+you must arrange to do this yourself.
=item on_delete / on_update