[tlug] Database design in Japan. (question)

["Birkir A. Barkarson" <birkirb@example.com>]

Since I started working in software development here in Japan I
accept many of the odd idiosyncrasies I have encountered such as the
propensity for natural keys to peculiar naming conventions, but
this latest case just strikes me as being stupid so I feel a need to elicit 
different opinions.

In front of me I have a database design where a product list table has a
product type property (this property is a hierarchical tree) and
is using six different fields to store each of the levels of the type tree the
product belongs to.

My instinct would be to have an external type per product table (with a
field pointing to the product table and another to a type table). Hierarchical
info could be in the type table (a parent field) if a single hierarchy is used
or in a separate one for multiple hierarchies.

Can anyone chip in some good reasons for and against the implementation I am
faced with on the one hand and my suggestion on the other?

Regards,

BAB