MySQL索引日常使用

EXPLAIN

SQL分析工具

EXPLAIN
SELECT
	* 
FROM
	invitation_assist_flow 
WHERE 
	  seller_id = 1
	AND activity_id = 1
	AND marketing_type = 1 
	AND new_user_id = 1 
	AND new_user_mobile = '1' 
	AND old_user_id = 1 
	AND old_user_mobile = '1'

分析：

可能使用了五种索引，涉及到2条数据，当涉及的数量大于75%左右时（自己用少数量测试）过多时，此时就会全表查，索引就会失效

标签：old,EXPLAIN,索引,user,MySQL,new,id,日常
来源： https://www.cnblogs.com/mainwoods/p/16455474.html