Monkey patch ActiveRecord to use bigints for ids and references

connection_adapters.rb

require 'active_record/connection_adapters/postgresql_adapter'

module ActiveRecord
  module ConnectionAdapters
    class TableDefinition
      def references(*args)
        options = args.extract_options!
        polymorphic = options.delete(:polymorphic)
        index_options = options.delete(:index)
        args.each do |col|
          column("#{col}_id", :bigint, options)
          column("#{col}_type", :string, polymorphic.is_a?(Hash) ? polymorphic : options) if polymorphic
          index(polymorphic ? %w(id type).map { |t| "#{col}_#{t}" } : "#{col}_id", index_options.is_a?(Hash) ? index_options : {}) if index_options
        end
      end
    end

    class PostgreSQLAdapter < AbstractAdapter
      NATIVE_DATABASE_TYPES[:primary_key] = 'bigserial primary key'
    end
  end
end