Ah, I should have been clearer. The default Catalyst::Model::CDBI class attempts to load *all* tables (using Class::DBI::Loader), which includes those without a primary key. Although I could have passed it a regexp of tables to include, that would soon become cumbersome. Since I only needed a few tables anyway, and they are all read-only (for this application), I bypassed C:M:CDBI for the tables I'm using.

Sorry for any confusion.