DRY your database.yml

Use anchors (&) and references (*) to merge options allowing your database.yml to not be so repetitive. Obviously you can organize in a way that makes the most sense to your organization but the following is an example where the database and test environments share some config and the production and staging environment share some config. So rather than repeating them you we just tag the first one with an anchor and then merge it (<<) into the next def with a reference (*).

development: &sqlite
  adapter: sqlite3
  database: db/development.sqlite3
  pool: 5
  timeout: 5000
test:
  <<: *sqlite
  database: db/test.sqlite3
staging: &mysql
  adapter: mysql
  encoding: utf8
  socket: /tmp/mysql.sock
  username: admin
  password: password
  database: staging
production:
  <<: *mysql
  database: production