クエリ: 複雑
  a_month_ago = Time.parse("2010-10-29")
  query = "Ruby 検索"
  sites.select do |record|
    condition = record.match(query) do |target|
      (target.title * 100) |
        (target.description * 10) |
        (target.content)
    end
    condition &
      (record.updated_at >= a_month_ago)
  end