开启autotrace报错

SQL> set autotrace traceonly statistics
SP2-0618: Cannot find the Session Identifier.  Check PLUSTRACE role is enabled
SP2-0611: Error enabling STATISTICS report
原因是因为system用户给scott做了授权，

最简单的解决办法：用sys用户重新授权一下：

SQL> @?/sqlplus/admin/plustrce

SQL>
SQL> drop role plustrace;

Role dropped.

SQL> create role plustrace;

Role created.

SQL>
SQL> grant select on v_$sesstat to plustrace;

Grant succeeded.

SQL> grant select on v_$statname to plustrace;

Grant succeeded.

SQL> grant select on v_$mystat to plustrace;

Grant succeeded.

SQL> grant plustrace to dba with admin option;

Grant succeeded.

SQL>
SQL> set echo off
SQL> grant plustrace to scott;

Grant succeeded.

SQL> set autot on

重新使用scott用户登录则正常开启
SQL> set autotrace traceonly statistics