在sqlplus中set autotrace on 出錯的解決辦法（ Unable to verify PLAN_TABLE）

在做sql語句的性能優化時執行set autotrace on時出錯．特記下解決過程，分享給大家，也方便自己以後查看
1。出錯

SQL> set autotrace on exp
SP2-0613: Unable to verify PLAN_TABLE format or existence
SP2-0611: Error enabling EXPLAIN report

2。解決（紅色爲輸入）

SQL*Plus: Release 10.1.0.2.0 - Production on 星期二 1月 12 15:00:56 2010
Copyright (c) 1982, 2004, Oracle. All rights reserved.
Connected to:
Oracle Database 10g Enterprise Edition Release 10.1.0.2.0 - Production
With the Partitioning, OLAP and Data Mining options
SQL> [color=red]@$ORACLE_HOME/rdbms/admin/utlxplan[/color]

Table created.

SQL> [color=red]create public synonym plan_table for plan_table; [/color]

Synonym created.

SQL>[color=red] grant all on plan_table to public ; [/color]
Grant succeeded.

SQL>[color=red] @$ORACLE_HOME/sqlplus/admin/plustrce [/color]SQL>
SQL> drop role plustrace;
drop role plustrace
*
ERROR at line 1:
ORA-01919: role 'PLUSTRACE' does not exist

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_$session to plustrace;

Grant succeeded.

SQL> grant plustrace to dba with admin option;

Grant succeeded.

SQL>
SQL> set echo off
SQL>[color=red] grant plustrace to public ; [/color]

Grant succeeded.

SQL>

3。做完上面操作就好了，