当网站的文章数量超过10万篇时，明显感觉到打开速度变慢了很多。
变慢的原因
select sql_calc_found_rows wp_posts.id from wp_posts where 1=1 and wp_posts.post_type = 'post' and (wp_posts.post_status = 'publish' ) order by wp_posts.post_date desc limit 0, 20 select found_rows()
query_posts和wp_query会因为sql_calc_found_rows出现慢查询。
解决办法一：彻底禁用sql_calc_found_rows
add_action('pre_get_posts', 'wndt_post_filter');
function wndt_post_filter($query) {
if (is_admin() or !$query->is_main_query()) {
return $query;
}
// 禁止查询 sql_calc_found_rows
$query->set('no_found_rows', true);
}
解决办法二：使用更加高效的explain方式
if ( ! function_exists( 'maizi_set_no_found_rows' ) ) {
/**
* 设置wp_query的 'no_found_rows' 属性为true，禁用sql_calc_found_rows
*
* @param wp_query $wp_query wp_query实例
* @return void
*/
function maizi_set_no_found_rows(\wp_query $wp_query)
{
$wp_query->set('no_found_rows', true);
}
}
add_filter( 'pre_get_posts', 'maizi_set_no_found_rows', 10, 1 );
if ( ! function_exists( 'maizi_set_found_posts' ) ) {
/**
* 使用 explain 方式重构
*/
function maizi_set_found_posts($clauses, \wp_query $wp_query)
{
// don't proceed if it's a singular page.
if ($wp_query->is_singular()) {
return $clauses;
}
global $wpdb;
$where = isset($clauses['where']) ? $clauses['where'] : '';
$join = isset($clauses['join']) ? $clauses['join'] : '';
$distinct = isset($clauses['distinct']) ? $clauses['distinct'] : '';
$wp_query->found_posts = (int)$wpdb->get_row("explain select $distinct * from {$wpdb->posts} $join where 1=1 $where")->rows;
$posts_per_page = (!empty($wp_query->query_vars['posts_per_page']) ? absint($wp_query->query_vars['posts_per_page']) : absint(get_option('posts_per_page')));
$wp_query->max_num_pages = ceil($wp_query->found_posts / $posts_per_page);
return $clauses;
}
}
add_filter( 'posts_clauses', 'maizi_set_found_posts', 10, 2 );
