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?
Exhibit:
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.
Explanation:
Requisition of Calibrate I/O (link)
Before running I/O calibration, ensure that the following requirements are met:
The user must be granted the SYSDBA privilege
timed_statistics must be set to TRUE
Asynchronous I/O must be enabled
When using file systems, asynchronous I/O can be enabled by setting the FILESYSTEMIO_OPTIONS
initialization parameter to SETALL. Ensure that asynchronous I/O is enabled for data files by running the
following query:
COL NAME FORMAT A50
SELECT NAME,ASYNCH_IO FROM V$DATAFILE F,V$IOSTAT_FILE I
WHERE F.FILE#=I.FILE_NO
AND FILETYPE_NAME=’Data File’;
Additionally, only one calibration can be performed on a database instance at a time.