优化MySQL多对多查询

优化MySQL多对多查询,mysql,optimization,query-optimization,Mysql,Optimization,Query Optimization,我在让MySQL在多对多查询中使用索引时遇到了问题,我已经在下面粘贴了相关信息 EXPLAIN SELECT * FROM interviews JOIN interview_category_links ON interviews.id = interview_category_links.inter_id JOIN categories ON interview_category_links.cat_id = categories.id WHERE categories.category_

我在让MySQL在多对多查询中使用索引时遇到了问题,我已经在下面粘贴了相关信息

EXPLAIN  SELECT *
FROM interviews
JOIN interview_category_links ON interviews.id = interview_category_links.inter_id
JOIN categories ON interview_category_links.cat_id = categories.id
WHERE categories.category_safe = 'news'
ORDER BY date DESC
LIMIT 15 

id  select_type  table  type  possible_keys  key  key_len  ref  rows  Extra
1  SIMPLE  categories  ALL  PRIMARY,id  NULL  NULL  NULL  16  Using where; Using temporary; Using filesort
1  SIMPLE  interview_category_links  ref  inter_id,inter_id_2,cat_id  cat_id  4  devel.categories.id  893   
1  SIMPLE  interviews  eq_ref  PRIMARY  PRIMARY  4  devel.interview_category_links.in...  1

在类别表中,我有索引(id,cat_id),在访谈类别链接表中,我有索引(cat_id,INTERU id)和个人索引(cat_id)以及索引(INTERU id)

你有访谈索引(id)吗

如果您删除了“订单日期描述”怎么办?查询是否运行得更快?如果是这样,您可能希望向该字段添加一个索引(我假设它是访谈表中的一列)