codeigniter - キーワード用のPyroCMSコードの最適化

Question

ブログモジュールのtagged（）メソッドに従ってこのメソッドを作成しました

public function genres($genre = null)
{
    $this->db->order_by('name', 'ASC');
    $result = $this->db->get('keywords');
    $genres = $result->result();

    if($genre)
    {
        $this->load->model('genres_m');
        // decode encoded cyrillic characters
        $genre = rawurldecode($genre) OR redirect('generos');

        $time[] = time();
        // Count total blog posts and work out how many pages exist
        $pagination = create_pagination(lang('ebooks:routes:genres') . '/' . $genre, $this->genres_m->count_genres_by($genre, array('entry_active' => 1)), NULL, 4);

        $time[] = time();
        // Get the current page of blog posts
        $books = $this->genres_m
            ->limit($pagination['per_page'])
            ->order_by('info_title', 'ASC')
            ->get_genres_by($genre, array('entry_active' => 1));

        $time[] = time();
        foreach ($books AS &$book)
        {
            $book->books_info_genre = Keywords::get($book->books_info_genre, 'blog/tagged');
            $book->url = site_url(lang('ebooks:routes:ebook') . '/' . $book->info_title . '/' . $book->id);
        }

        $time[] = time();
        // Set meta description based on post titles
        //$meta = $this->_posts_metadata($books);

        $name = str_replace('-', ' ', $genre);

        // Build the page
        $this->template
            ->title($this->_template_title(lang('ebooks:of').' '.$name))
            ->set_metadata('description', $this->_template_title(lang('ebooks:of').' '.$name))
            ->set_metadata('keywords', $this->_template_title(lang('ebooks:of').' '.$name))
            ->set('genres', $genres)
            ->set('books', $books)
            ->set('genre', $genre)
            ->set('time', $time)
            ->set('pagination', $pagination)
            ->build('genres-list');
    }
    else
    {
        $this->template->title($this->_template_title(lang('ebooks:genres_by')))
            ->set_metadata('description', $this->_template_title(lang('ebooks:genres_by')))
            ->set_metadata('keywords', $this->_template_title(lang('ebooks:genres_by')))
            ->set('genres', $genres)
            ->build('genres-list');
    }
}

そして、これはモデルです：

public function count_genres_by($genre, $params)
{
    return $this->db->select('*')
        ->from('downloads_books_book_info')
        ->join('keywords_applied', 'keywords_applied.hash = downloads_books_book_info.books_info_genre')
        ->join('keywords', 'keywords.id = keywords_applied.keyword_id')
        ->where('keywords.name', str_replace('-', ' ', $genre))
        ->where($params)
        ->count_all_results();
}

    public function get_genres_by($genre, $params)
{
    return $this->db->select('*')
        ->from('downloads_books_book_info')
        ->join('keywords_applied', 'keywords_applied.hash = downloads_books_book_info.books_info_genre')
        ->join('keywords', 'keywords.id = keywords_applied.keyword_id')
        ->where('keywords.name', str_replace('-', ' ', $genre))
        ->where($params)
        ->get()
        ->result();
}

コードの最初の部分でわかるように、time（）を4回取得し、遅延を与えています。

18:49-19:03-19:41-19:41

約5Kのエントリを持つDBがあります。このコードを最適化するにはどうすればよいですか？