database-level cascade or restrict will take precedence over a
DBIx-Class-based cascading delete.
+If you delete an object within a txn_do() (see L<DBIx::Class::Storage/txn_do>)
+and the transaction subsequently fails, the row object will remain marked as
+not being in storage. If you know for a fact that the object is still in
+storage (i.e. by inspecting the cause of the transaction's failure), you can
+use C<< $obj->in_storage(1) >> to restore consistency between the object and
+the database. This would allow a subsequent C<< $obj->delete >> to work
+as expected.
+
See also L<DBIx::Class::ResultSet/delete>.
=cut