mysql - 查询优化

Question

我安装的 WP 包含超过 50k 篇文章。有时，由于许多锁定的查询，网站速度会变慢。似乎某些代码正在启动像这样的疯狂查询

SELECT SQL_CALC_FOUND_ROWS  wp_posts.* 
   FROM wp_posts  
   WHERE 1=1  
   AND wp_posts.ID NOT IN (43500, ... )) 
   AND wp_posts.ID NOT IN ( SELECT tr.object_id 
                                   FROM wp_term_relationships AS tr 
                                   INNER JOIN wp_term_taxonomy AS tt
                                   ON tr.term_taxonomy_id = tt.term_taxonomy_id WHERE tt.taxonomy = 'category' AND tt.term_id IN ('20207', '20788', '20789', '20790', '20791', '20792', '20793', '20794', '20795', '20796', '20797', '20798', '20799', '20800', '20801', '20802', '20803', '20804', '20805', '20806', '20807', '20808', '21012') ) 
                                  AND wp_posts.post_type = 'post' 
                                  AND (wp_posts.post_status = 'publish')  
   ORDER BY wp_posts.post_date DESC LIMIT 0, 5

wp_posts ID NOT IN (...) 列表包含超过 5000 个 ID，这会导致非常漫长的查询。

这个查询从哪里来？我该如何改进它？

Answer 1

在JOIN中使用的表中的外键中创建索引将提高性能