普通用户开启AUTOTRACE 功能

　 AUTOTRACE是一个SQL*Plus工具,用于跟踪SQL的执行计划,收集执行时所耗用资源的统计信息。系统账户本身具有AUTOTRACE，其他账户需要通过手动赋予

一. 用系统账户登录（DBA）

 SQL> set autotrace traceonly
 SQL> select * from hr.jobs;

 19 rows selected.

 Execution Plan
 ----------------------------------------------------------
 Plan hash value: 944056911

 --------------------------------------------------------------------------
 | Id  | Operation         | Name | Rows  | Bytes | Cost (%CPU)| Time     |
 --------------------------------------------------------------------------
 |   0 | SELECT STATEMENT  |      |    19 |   627 |     3   (0)| 00:00:01 |
 |   1 |  TABLE ACCESS FULL| JOBS |    19 |   627 |     3   (0)| 00:00:01 |
 --------------------------------------------------------------------------

 Statistics
 ----------------------------------------------------------
           0  recursive calls
           0  db block gets
           9  consistent gets
           0  physical reads
           0  redo size
        1452  bytes sent via SQL*Net to client
         396  bytes received via SQL*Net from client
           3  SQL*Net roundtrips to/from client
           0  sorts (memory)
           0  sorts (disk)
          19  rows processed

 SQL> 

二.授予其他用户AUTOTRACE 功能

2.1 创建基础表　　运行$ORACLE_HOME/rdbms/admin/utlxplan脚本来创建plan_table

 SQL> conn /as sysdba                        --用系统账户登录
 Connected.
 SQL> start $ORACLE_HOME/rdbms/admin/utlxplan --执行utlxplan脚本

 Table created.

 SQL> create public synonym plan_table for plan_table;--为表plan_table创建公共同义词    

 Synonym created.

 --如果需要限制Autotrace权限，可以把对public的授权改为对特定user的授权。
 SQL> grant all on plan_table to public;--将同义词表plan_table授予给所有用户

 Grant succeeded.

 SQL>

2.2 创建角色　　运行$ORACLE_HOME/sqlplus/admin/plustrce.sql脚本

 SQL> start $ORACLE_HOME/sqlplus/admin/plustrce.sql  --执行创建角色的脚本
 SQL>
 --以下是脚本执行过程：首先 删除PLUSTRACE角色，重建PLUSTRACE角色，赋予权限
 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_$mystat to plustrace;

 Grant succeeded.

 SQL> grant plustrace to dba with admin option;

 Grant succeeded.

 SQL>
 SQL> set echo off
 SQL>         

2.3 角色的授予

　　在创建角色后，DBA首先被授予了该角色，且可以将角色授予其它组和用户。可以手工把plustrace授予给public,则该数据库内所有的用户都将拥有plustrace角色的权限。也可以单独授予给某个组和用户。

 --授予给单独用户
 SQL> grant plustrace to hr;

 Grant succeeded.

 --授予给所有用户
 SQL> grant plustrace to public;

 Grant succeeded.

 SQL>

　　现在所有用户即可使用autotrace 功能

三、AUTOTRACE的几个选项

 --在sql提示符下输入set autot后将会给出设置autotrace的提示，如下：
 SQL> set autot
 Usage: SET AUTOT[RACE] {OFF | ON | TRACE[ONLY]} [EXP[LAIN]] [STAT[ISTICS]]

 set autotrace off :缺省值，将不生成autotrace 报告
 set autotrace on :包含执行计划和统计信息
 set autotrace traceonly :等同于set autotrace on，但不显示查询输出的结果
 set autotrace on explain :只显示优化器执行路径报告
 set autotrace on statistics :只显示执行统计信息        

四.hr用户示例

 SQL> conn hr/hr123
 Connected.
 SQL> set autotrace traceonly
 SQL> select * from jobs;

 19 rows selected.

 Execution Plan
 ----------------------------------------------------------
 Plan hash value: 944056911

 --------------------------------------------------------------------------
 | Id  | Operation         | Name | Rows  | Bytes | Cost (%CPU)| Time     |
 --------------------------------------------------------------------------
 |   0 | SELECT STATEMENT  |      |    19 |   627 |     3   (0)| 00:00:01 |
 |   1 |  TABLE ACCESS FULL| JOBS |    19 |   627 |     3   (0)| 00:00:01 |
 --------------------------------------------------------------------------

 Statistics
 ----------------------------------------------------------
           1  recursive calls
           0  db block gets
           9  consistent gets
           0  physical reads
           0  redo size
        1452  bytes sent via SQL*Net to client
         396  bytes received via SQL*Net from client
           3  SQL*Net roundtrips to/from client
           0  sorts (memory)
           0  sorts (disk)
          19  rows processed

 SQL>