Question

我目前使用自定义wordpress MySQL查询来获取某些购物网站的相关产品。我刚刚描述了我的页面，我注意到这个查询大约需要3秒钟，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                     |
+----+-------------+-------+--------+-------------------------------------------------+------------------+---------+------------------------------------+------+---------------------------------+

正如你所看到我正在使用临时表而我不想，我想创建一个索引来加速这个查询，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，并且必须检查所有2822行的临时表中的+排序。话虽这么说，2822行不是那么大，它可以解释如此长的查询时间。 DB或磁盘上的负载是否很高？反正...

通过更仔细地查看您的查询，这非常令人困惑。显然，您有wp_term_taxonomy.term_taxonomy_id和wp_term_relationships.term_taxonomy_id ，但可能的索引位于wp_term_taxonomy.term_id_taxonomy。

看到区别？ term_taxonomy_id≠term_id_taxonomy。这是拼写错误吗？一个错误？一个“功能”？

“使用临时”与自定义Wordpress搜索

1 个答案: