database design help

Hi, I'm coding a little application to make couples profile. The problem is I just don't know how to create my databases so that their are no bottlenecks and that I can have a relation. The way I see it is that their would be a user database and a profile database and they would link 2 to 1. Is this the right way? In the user db I would store their userid and some session info, should I use their userid as primary key?

DB Scheme User1---            >---Profile User2---

User DB -userid (primary key?) -profileid -session info -timestamp

Profile DB -personnal info

Any help would be appreciated, thanks' in advance.

Rails' convention is that every ActiveRecord object is identified by an 'id' column (auto-incrementing, int primary key) and foreign keys are named <other_table>_id. The nice thing about following the conventions is that it greatly simplifies your coding (in some cases eliminating code!). So your model would look something like this:

create_table :users do |t|   t.integer :profile_id   t.string :crypted_password   ... etc ... end

class User < ActiveRecord::Base   belongs_to :profile end

create_table :profiles do |t|   ... personal info ... end

class Profile < ActiveRecord::Base   has_many :users end

With those migrations and classes you do not need to specify the name of the primary key (assumed to be id... and written into the create_table migration for you). You also don't need to tell the has_many macro the name of the foreign key to use when looking up users (or the User objects which Profile to file) since it's assumed to be profile_id.