Open Stack

Hi

I am looking at ceilometer DB code. I find there are 3 tables (UniqueName, Event, Trait), and in Trait, the two columns "name_id" and "event_id" refer to table UniqueName and table Event.

My question is why we need UniqueName and Event, because in both tables there are no many other columns, so why not fill unique_name into Trait directly.

Thanks in advance.
--
Shane