SQL> set timing on
SQL> select empno,ename,job from   scott.emp ;
     EMPNO ENAME      JOB                                                      
---------- ---------- ---------                                                
      7369 xiaonan    CLERK                                                    
      7499 ALLEN      SALESMAN                                                 
      7521 WARD       SALESMAN                                                 
      7566 JONES      MANAGER                                                  
      7654 MARTIN     SALESMAN                                                 
      7698 BLAKE      MANAGER                                                  
      7782 CLARK      MANAGER                                                  
      7788 SCOTT      ANALYST                                                  
      7839 KING       PRESIDENT                                                
      7844 TURNER     SALESMAN                                                 
      7876 ADAMS      CLERK                                               
      7900 JAMES      CLERK                                                    
      7902 FORD       ANALYST                                                  
      7934 MILLER     CLERK                                                    

已选择14行。
已用时间:  00: 00: 00.01

以上数字输出分别是：Hours:Minutes:Seconds.Milliseconds