OCP 1Z0 053 266

266.View the Exhibit to examine the parameters set for your database instance. You execute the following 
command to perform I/O calibration after the declaration of bind variables in the session that are used in 
the command: 
SQL> EXECUTE dbms_resource_manager.calibrate_io( num_physical_disks=>1, - max_latency=>50, 
-max_iops=>:max_iops, -max_mbps=>:max_mbps, - 
actual_latency=>:actual_latency); 
Which statement describes the consequence? 

A. The command produces an error. 
B. The calibration process runs successfully and populates all the bind variables. 
C. The calibration process runs successfully but the latency time is not computed. 
D. The calibration process runs successfully but only the latency time is computed. 
Answer: A 

http://docs.oracle.com/cd/E11882_01/appdev.112/e40758/d_resmgr.htm#ARPLS050
Only users with the SYSDBA privilege can run this procedure. Qualified users must also turn on timed_statistics, and ensure asynch_io is enabled for datafiles. This can be achieved by setting filesystemio_options to either ASYNCH or SETALL. One can also query the asynch_io status by means of the following SQL statement:

SQL> alter session set statistics_level = basic;会话已更改。SQL> alter session set timed_statistics = false;会话已更改。SQL> SET SERVEROUTPUT ONSQL> DECLARE  2    lat  INTEGER;  3    iops INTEGER;  4    mbps INTEGER;  5  BEGIN  6  -- DBMS_RESOURCE_MANAGER.CALIBRATE_IO (<DISKS>, <MAX_LATENCY>, iops, mbps, lat);  7     DBMS_RESOURCE_MANAGER.CALIBRATE_IO (1, 50, iops, mbps, lat);  8  9    DBMS_OUTPUT.PUT_LINE ('max_iops = ' || iops); 10    DBMS_OUTPUT.PUT_LINE ('latency  = ' || lat); 11    DBMS_OUTPUT.PUT_LINE ('max_mbps = ' || mbps); 12  end; 13  /DECLARE*第 1 行出现错误:ORA-56709: timed_statistics 已设置为 FALSEORA-06512: 在 "SYS.DBMS_RMIN", line 463ORA-06512: 在 "SYS.DBMS_RESOURCE_MANAGER", line 1302ORA-06512: 在 line 7