Access denied; you need (at least one of) the RELOAD privilege(s) for this operation

1. reload 是 administrative 级的权限，即 server administration；这类权限包括：
   CREATE USER, PROCESS, RELOAD, REPLICATION CLIENT, REPLICATION SLAVE, SHOW DATABASES, SHUTDOWN, SUPER

2. 这类权限的授权不是针对某个数据库的，因此须使用on *.* 来进行：

  grant reload on *.* to 'test'@'localhost';