[Rails] How to structure my database

Hi!

I'm creating an app that will import products from several XML feeds. In
the XML there is a category specified, like T-Shirt for instance. The
problem is that different resellers specify the categories differently. For
instance, what one reseller calls "T-Shirts" another may call "T-Shirt", a
third "short sleeved shirts" and so on.

I want to somehow map these categories to the categories I have myself. So
I need some tips on how I should create my database.

The idea I have is to create a "raw_categories" table which contains the
name of the resellers category and a "category_id" which has a belongs_to
relationship to my own "categories" table. Then when I import I simply try
to find a raw_category which has a matching name and if there is one, pick
it, otherwise add a new one. This new one I can then manually relate to one
of my own categories.


Do you understand how I mean, and is it a good approach? Is there a
better/more efficient way?

- If this is a good idea. How do I do it in Rails? Should I use something
like this (I think I've seen something like this in the API doc):
# products model
has_one :category, :through => :raw_categories

I estimate that there will be about 40k to 100k products in the database.

Regards
Linus