mysql8.0 运维相关新特性（未完待续）

https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-0.html
MySQL8.0.0
The current maximum auto-increment counter value is now written to the redo log each time the value changes, and saved to an engine-private system table on each checkpoint。

MySQL 8.0.1
https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-1.html
开始支持descending indexes

MySQL 8.0.11
https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-11.html

账号相关
1、使用grant创建用户的方式被废弃，只能使用create user方式
2、create user ... IDENTIFIED BY PASSWORD 'hash_string' 方式已废弃
3、password()函数已废弃，即通过update mysql.user set password=password('xxx')这种方式不可用了。

MySQL 8.0.12
https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-12.html
1、InnoDB现在支持 ALGORITHM=INSTANT以下 ALTER TABLE操作：

MySQL 8.0.13
https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-13.html#mysqld-8-0-13-feature
1、开始支持functional indexes 和 index skip scan
2、gtid环境开始支持 CREATE TEMPORARY TABLE and DROP TEMPORARY TABLE

MySQL 8.0.14
https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-14.html

1、允许一个帐户具有双重密码，
RETAIN CURRENT PASSWORD,保留当前的密码作为辅助密码
DISCARD OLD PASSWORD,丢弃不再需要的辅助密码

MySQL 8.0.16
https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-16.html

1、mysql升级相关调整
https://mysqlserverteam.com/mysql-8-0-16-mysql_upgrade-is-going-away/

MySQL 8.0.17
https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-17.html

1、引入Clone Plugin

MySQL 8.0.20
https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-20.html

1、hash join

MySQL 8.0.21
CREATE TABLE ... SELECT statements. Prior to MySQL 8.0.21, CREATE TABLE ... SELECT statements are not allowed when using GTID-based replication