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DBMS_RESOURCE_MANAGER.CALIBRATE_IO

dbms_resource_manager.calibrate_io calibrates I/O capabilities by gathering statistics on I/O operations. This is typically required only after hardware has changed. 
declare
   max_io_per_second pls_integer;
   max_mb_per_second pls_integer;
   actual_latency    pls_integer;

begin

   dbms_resource_manager.calibrate_io(
   -- num_physical_disks    =>   use default
   -- max_latency           =>   use default
      max_iops              =>   max_io_per_second,
      max_mbps              =>   max_mb_per_second,
      actual_latency        =>   actual_latency
   );


   dbms_output.put_line('Max io/s: ' || to_char(max_io_per_second, '9999990'      ));
   dbms_output.put_line('Max MB/s: ' || to_char(max_mb_per_second, '9999990'      ));
   dbms_output.put_line('Act. lat: ' || to_char(actual_latency   ,    '9990.99999'));

end;
/

select * from v$io_calibration_status;
select * from dba_rsrc_io_calibrate;

See also

dbms_resource_manager

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