cp data file

cp /var/lib/mysql /data -Rf
chown -R mysql:mysql /data/mysql

AppArmor

/etc/apparmor.d/local/usr.sbin.mysqld

/data/mysql r,
/data/mysql/** rwk, 

sudo systemctl reload apparmor 

sudo as myql

sudo -s -u mysql

mysql 时间类型支持微秒

MySQL permits fractional seconds for TIME, DATETIME, and TIMESTAMP values, with up to microseconds (6 digits) Mysql DATETIME(6) DATETIME[(fsp)] The fsp value, if given, must be in the range 0 to 6. A value of 0 signifies that there is no fractional part. If omitted, the default precision is 0. (This differs from the standard SQL default of 6, for compatibility with previous MySQL versions.)

检查表大小

select table_schema as database_name, table_name, round( (data_length + index_length) / 1024 / 1024, 2) as total_size, round( (data_length) / 1024 / 1024, 2) as data_size, round( (index_length) / 1024 / 1024, 2) as index_size from information_schema.tables where table_schema not in ('information_schema', 'mysql', 'performance_schema' ,'sys') and table_type = 'BASE TABLE' -- and table_schema = 'your database name' order by total_size desc limit 10;