Mejorar la velocidad de nuestra web con PHP

Si queremos modificar las búsquedas que ofrece WordPress para que devuelva lo que nosotros queremos tan solo hay que hacer dos funciones para dos filtros:

add_filter('posts_results', 'mi_search');
function mi_search($posts) {
  $s = get_query_var('s');
  if (condicion($s)) {
    $posts = array();
    $paged = intval(get_query_var('paged'));
    if ($paged < 1) $paged = 1;
    $posts_per_page = intval(get_query_var('posts_per_page'));
    $from = ($paged-1)*$posts_per_page;
    global $wpdb;
    $_posts = $wpdb->get_results("select post_id from $wpdb->posts where loquesea order by post_id desc limit $from, $posts_per_page");
    foreach($_posts as $p) {
      $posts[] = get_post($p->post_id);
    }
  }
  return $posts;
}

add_filter('found_posts', 'mi_found_posts');
function mi_found_posts($n) {
  $s = get_query_var('s');
  if (condicion($s)) {
    global $wpdb;
    $res = $wpdb->get_results("select count(*) as n from $wpdb->posts where condicion ");
    $n = $res[0]->n;
  }

  return $n;
}