SQL> set autotrace

Usage: SET AUTOT[RACE] {OFF | ON | TRACE[ONLY]} [EXP[LAIN]] [STAT[ISTICS]]

SQL> set autotrace on

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

SP2-0611: Error enabling STATISTICS report

SQL> conn /as sysdba

Connected.

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> 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> grant plustrace to scott;

Grant succeeded.

SQL> conn scott/tiger

Connected.

SQL> set autotrace on

SQL> select count(*) from emp;

  COUNT(*)

----------

    14

Execution Plan

----------------------------------------------------------

Plan hash value: 2937609675

-------------------------------------------------------------------

| Id  | Operation     | Name   | Rows  | Cost (%CPU)| Time      |

-------------------------------------------------------------------

|   0 | SELECT STATEMENT |      |    1 |    1   (0)| 00:00:01 |

|   1 |  SORT AGGREGATE  |      |    1 |           |      |

|   2 |   INDEX FULL SCAN| PK_EMP |    14 |    1   (0)| 00:00:01 |

-------------------------------------------------------------------

Statistics

----------------------------------------------------------

      1  recursive calls

      0  db block gets

      1  consistent gets

      1  physical reads

      0  redo size

    526  bytes sent via SQL*Net to client

    520  bytes received via SQL*Net from client

      2  SQL*Net roundtrips to/from client

      0  sorts (memory)

      0  sorts (disk)

      1  rows processed

SQL>