With hstore you can add schema-less data to PostgreSQL. This allows you to store model attributes without creating separate database columns. Watch how to do this using the activerecord-postgres-hstore gem.
Rails 4.0 is still unfinished, but it is shaping up to become a great release. Here I show how to setup a new Rails 4.0 (edge) application and walk through many of its new features.
(20 minutes)
Postgres is a feature-packed relational database that every Rails developer should consider using. Here you will learn how to install it, add it to a new application, and transition from an existing SQLite app using the "taps" gem.
(8 minutes)