One more point -- rake migrations are great and ActiveRecord is pretty cool, but both work at a "lowest" denominator level. What this means is that you can have this defined in Postgres:
create table things (
id integer not null primary key,
some_text varchar(100)
constraint things_some_text_un unique
);create table gadgets (
id integer not null primary key,
thing_id integer not null
constraint gadgets_fk references things(id),
status_code varchar(1)
constraint gadgets_status_code_ck check (status_code in ('c','o')) default 'c'
);
But all (well, most of) these wonderful constraints will not be re-created once you run rake migrate on another machine....
