# File lib/heroku/commands/pg.rb, line 36
    def extract_db(opts={})
      db_id = extract_option("--db")
      (name, database) = resolve_db_id(db_id, :default => 'DATABASE_URL') # get DATABASE_URL first

      return name, database if opts[:include_shared] || name.match("HEROKU_POSTGRESQL")

      (name, database) = resolve_db_id(db_id, :default => heroku_postgresql_var_names.first) # get any HEROKU_POSTGRESQL_*_URL next
      return name, database if name.match("HEROKU_POSTGRESQL")
    end