Migrate from Mongo to Postgres in Rails 3.1

gistfile1.txt

Tested on: Rails 3.1, Mongoid 2.0.1, pg 0.12.0 gem

Migrate from Mongo to PG
1. remove mongoid gem
2. add pg gem
3. in application.rb re-add ActiveRecord
4. for all models
- inherit from ActiveRecord::Base
- get rid of Mongoid:Document line
- make migrations and put fields there
- redo embedded relats
5. In initializers/devise.rb may need:
  require 'devise/orm/active_record'
 #active_record should be default but can be problems
6. Invalidate Session if nec by changing secret_token in initializers
- See https://gist.github.com/1504625
- happens b/c session will prolly have Bson which no longer valid
7. Modify any mongoid-specific query, etc. code