Best solution for accessing multiple databases?

I'm currently running my Rails app out of PostgreSQL database but I've
gotten to a point where I need to query another Oracle database to
retrieve a single record.

I've seen approaches like this:

But is this the right method for me?

When a user uses my application it determines who they are via their
Windows Login. Using that login I have the capability to query an
Oracle database and retrieve all the information on that user. So when
the user logs into my application I would like to make the call to that
Oracle database, pull down their information and continue with the
application never having to access the Oracle database again.

Why wouldn't you setup the oracle database in database.yml then create a model like 'AllUserInfo' or something that makes more sense and define it like this:

class AllUserInfo < ActiveRecord::Base
   establish_connection 'oracle_db_defined_in_yml_file'
   set_table_name 'whatever my table name is'

and then just do...

all_info_about_a_user = AllUserInfo.find(:first, :conditions....)