1, The installation says we must use debian-sys-maint, Why must? The installation guide give us the not choice, it seems 'not must'.
2, I am using 'mysql-community-server', 5.7.24-1ubuntu18.04 . which doesn't have debian-sys-maint reserved user.
3, Is 'mysql-community-server', 5.7.24-1ubuntu18.04 mysql.sys is equvilent to debian-sys-maint ?
4. where is the password of debian-sys-maint or mysql.sys ? In my case, it is not the same as root