autotrace是SQL*PLUS中的一个工具，可以显示所执行查询的解释计划（explain plan）以及所用的资源。
　　（如果是其它版本的话可能要先执行/rdbms/admin/utlxplan.sql；再create public synonym plan_table for plan_table;）
　　grant all on plan_table to public；
　　运行sqlplus/admin/plustrace.sql；内容如下： 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 "/ 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
　　再执行：
　　grant plustrace to public；
　　set autotrace off;
　　set autotrace on explain;
　　set autotrace on statistics;
　　set autotrace on;