Create an index rules: https://www.cnblogs.com/helloworldlx/p/8651583.html
The results explain inspection index: https://blog.csdn.net/dennis211/article/details/78170079
Written in a very practical sense
I intend to use it
I use the next record, according to the source blog said, I chose to add multiple fields index, plus an index code is as follows
#添加索引
ALTER TABLE table_name ADD INDEX query_index (tained_id, is_group, send_time)Then explain test
explain select * from table_name where tained_id =42 and is_group=0 ORDER BY send_time ASC
The results are as follows
Attach a screenshot of the source blog:
