Rails - Nov 2006 - excluding column from associations

Is there a recommended way to exclude a column from associations?  for example:

Model Album
  has_and_belongs_to_many :photos

Model Photo
  has_and_belongs_to_many :albums

Photo Table
int  :id
int  :order
blob :data     <-- the culprit!

--------------------------------------------------------

I''m caching the output of Photo.data in a controller, but i
don''t want
to select the photo data every time i do something like album.photos.
The data blob is BIG  (i''m caching a resized version on the way out)
and I think it''s killing my performance.

I''d like the Album Model to say something like
  has_and_belongs_to_many :photos, :exclude_column => :data

I can''t seem to find the right words to explain my problem to google
-- no love there.
Anyone have any info for me?

Thanks in advance,
Clint Troxel

-- 
clint troxel _ Open End Studios _
307.413.0366
http://openendstudios.com