Some note from Oracle’s documentation “Applications that spend the majority of CPU time waiting for I/O activity to complete are said to be I/O-bound.Prerequisites for I/O Calibration”.
Values to parameters
timed_statistics=TRUE
“When using file systems, asynchronous I/O can be enabled by setting the FILESYSTEMIO_OPTIONS initialization parameter to SETALL.”
DBMS_RESOURCE_MANAGER.CALIBRATE_IO procedure
SET SERVEROUTPUT ON
DECLARE
lat INTEGER;
iops INTEGER;
mbps INTEGER;
BEGIN
— DBMS_RESOURCE_MANAGER.CALIBRATE_IO (<DISKS>, <MAX_LATENCY>, iops, mbps, lat);
DBMS_RESOURCE_MANAGER.CALIBRATE_IO (2, 10, iops, mbps, lat);
DBMS_OUTPUT.PUT_LINE (‘max_iops = ‘ || iops);
DBMS_OUTPUT.PUT_LINE (‘latency = ‘ || lat);
dbms_output.put_line(‘max_mbps = ‘ || mbps);
end;
/
To query the I/O calibration process: V$IO_CALIBRATION_STATUS view.
To see the results : DBA_RSRC_IO_CALIBRATE table.
References:
Oracle® Database Performance Tuning Guide 8 I/O Configuration and Design
