环境：Oracle 10g,11g.
现象：在一次迁移测试中，发现有这样的角色赋权会报错不存在：
SYS@orcl> grant PLUSTRACE to jingyu;
grant PLUSTRACE to jingyu
*
ERROR at line 1:
ORA-01919: role 'PLUSTRACE' does not exist
查询发现这个角色是需要手工执行脚本创建，直接执行Oracle自带的SQL脚本@?/sqlplus/admin/plustrce.sql即可：
SYS@orcl> @?/sqlplus/admin/plustrce.sql
SYS@orcl>
SYS@orcl> drop role plustrace;
drop role plustrace
*
ERROR at line 1:
ORA-01919: role 'PLUSTRACE' does not exist
SYS@orcl> create role plustrace;
Role created.
SYS@orcl>
SYS@orcl> grant select on v_$sesstat to plustrace;
Grant succeeded.
SYS@orcl> grant select on v_$statname to plustrace;
Grant succeeded.
SYS@orcl> grant select on v_$mystat to plustrace;
Grant succeeded.
SYS@orcl> grant plustrace to dba with admin option;
Grant succeeded.
SYS@orcl>
SYS@orcl> set echo off
SYS@orcl>
可以看到这个角色就是封装了对v_$sesstat，v_$statname，v_$mystat这几个视图的查询权限。
执行以后就可以直接赋予用户PLUSTRACE的角色了：
SYS@orcl> grant PLUSTRACE to jingyu;