SP2-0618: Cannot find the Session Identifier. Check PLUSTRACE role is enabled错误

普通用户在SQL*Plus中开启AUTOTRACE报告时，遇到SP2-0618: Cannot find the Session Identifier. Check PLUSTRACE role is enabled错误。如下所示：
SYS@ db02 > conn scott/tiger
SQL> set autotrace on;
SP2-0618: Cannot find the Session Identifier. Check PLUSTRACE role is enabled
SP2-0611: Error enabling STATISTICS report

此时应该检查数据库是否已经创建了角色PLUSTRACE，使用下面脚本检查角色PLUSTRACE是否存在。
SELECT * FROM DBA_ROLES WHERE ROLE='PLUSTRACE';

如果角色不存在，应该去$ORACLE_HOME/sqlplus/admin/目录下，你会找到plustrce.sql脚本文件。
cd $ORACLE_HOME/sqlplus/admin/

more plustrce.sql
--
-- Copyright (c) Oracle Corporation 1995, 2002. All Rights Reserved.
--
-- NAME
-- plustrce.sql
--
-- DESCRIPTION
-- Creates a role with access to Dynamic Performance Tables
-- for the SQL*Plus SET AUTOTRACE ... STATISTICS command.
-- After this script has been run, each user requiring access to
-- the AUTOTRACE feature should be granted the PLUSTRACE role by
-- the DBA.
--
-- USAGE
-- sqlplus "sys/knl_test7 as sysdba" @plustrce
--
-- Catalog.sql must have been run before this file is run.
-- This file must be run while connected to a DBA schema.

set echo on

drop role plustrace;
create role plustrace;

grant select on v_$sesstat to plustrace;
grant select on v_$statname to plustrace;
grant select on v_$mystat to plustrace;
grant plustrace to dba with admin option;

set echo off

执行该脚本就会创建角色PLUSTRACE，如下所示。然后将该角色授予对应用户即可。
@?/sqlplus/admin/plustrce.sql
grant plustrace to scott;