mysql - "Using Temporary"与自定义 WordPress 搜索

Question

我目前使用自定义 WordPress MySQL 查询来获取我的一些购物网站的相关产品。我刚刚分析了我的页面，我注意到这个查询大约需要 3 秒，但我不确定如何优化它。查询如下:

explain select 
    p . *,
    unix_timestamp(p.post_modified) as post_modified_ut,
    unix_timestamp(p.post_date) as post_date_ut,
    (((2.3 * (MATCH (p.post_title) AGAINST ('Motorola+MBP+36+Digital+Video+Monitor' IN BOOLEAN MODE)))) + (0.6 * (MATCH (p.post_content) AGAINST ('Motorola+MBP+36+Digital+Video+Monitor' IN BOOLEAN MODE)))) AS relevance
from
    wp_posts as p,
    wp_terms as t,
    wp_term_taxonomy as tt,
    wp_term_relationships as tr
where
    (MATCH (p.post_title , p.post_content) AGAINST ('Motorola+MBP+36+Digital+Video+Monitor' IN BOOLEAN MODE))
        and tr.object_id = p.ID
        and tr.term_taxonomy_id = tt.term_taxonomy_id
        and tt.term_id = t.term_id
        and p.post_type = 'post'
        and p.post_status in ('inherit' , 'publish')        
group by p.ID , p.post_title
order by relevance desc
limit 5;

解释的结果是:

+----+-------------+-------+--------+-------------------------------------------------+------------------+---------+------------------------------------+------+---------------------------------+
| id | select_type | table | type   | possible_keys                                   | key              | key_len | ref                                | rows | Extra                           |
+----+-------------+-------+--------+-------------------------------------------------+------------------+---------+------------------------------------+------+---------------------------------+
|  1 | SIMPLE      | tt    | ALL    | PRIMARY,term_id_taxonomy                        | NULL             | NULL    | NULL                               | 2822 | Using temporary; Using filesort |
|  1 | SIMPLE      | t     | eq_ref | PRIMARY                                         | PRIMARY          | 8       | reviewexplorer.tt.term_id          |    1 | Using index                     |
|  1 | SIMPLE      | tr    | ref    | PRIMARY,term_taxonomy_id                        | term_taxonomy_id | 8       | reviewexplorer.tt.term_taxonomy_id |    5 |                                 |
|  1 | SIMPLE      | p     | eq_ref | PRIMARY,type_status_date,searches,searches_more | PRIMARY          | 8       | reviewexplorer.tr.object_id        |    1 | Using where                     |
+----+-------------+-------+--------+-------------------------------------------------+------------------+---------+------------------------------------+------+---------------------------------+

正如您所看到的，我正在使用临时表，但我不想这样做，我想创建一个索引来加速此查询，但我不完全理解解释告诉我的内容。

Answer 1

显然，MySQL 无法在 wp_term_taxonomy 表上使用任何索引，并且必须在临时表中检查+排序所有 2822 行。话虽这么说，2822 行并没有大到可以解释这么长的查询时间。数据库或磁盘负载高吗？无论如何...

<小时/>

通过更仔细地查看您的查询，您会发现它非常令人困惑。显然，您有一个 wp_term_taxonomy.term_taxonomy_id 和 wp_term_relationships.term_taxonomy_id 但是可能的索引位于 wp_term_taxonomy.term_id_taxonomy 上。

看出区别了吗？ term_taxonomy_id ≠ term_id_taxonomy。
这是一个错字吗？一个错误？ “功能”？