Measure average I/O-load and CPU-usage on Oracle database instance

Short overview on peak I/O requests, transfer volume and CPU-usage for given time range.
Based on average values within AWR-cycle.

SELECT /* DB-Tools Ramm average system load */
       Instance_Number, MIN(Begin_Time) Start_Range, MAX(End_Time) End_Range,
       MAX(Phys_Write_Total_kB_per_Sec)                                            Max_Phys_Writes_kB_per_Sec,
       MAX(Begin_Time) KEEP (DENSE_RANK LAST ORDER BY Phys_Write_Total_kB_per_Sec) Max_Write_per_Sec_BeginTime,
       MAX((End_Time-Begin_Time)*1440) KEEP (DENSE_RANK LAST ORDER BY Phys_Write_Total_kB_per_Sec) Cycle_Minutes_1,  
       MAX(Phys_Read_Total_kB_per_Sec)                                             Max_Phys_Read_kB_per_Sec,
       MAX(Begin_Time) KEEP (DENSE_RANK LAST ORDER BY Phys_Read_Total_kB_per_Sec)  Max_Read_per_Sec_BeginTime, 
       MAX((End_Time-Begin_Time)*1440) KEEP (DENSE_RANK LAST ORDER BY Phys_Read_Total_kB_per_Sec) Cycle_Minutes_2,  
       MAX(Phys_Write_IO_per_Sec)                                                  Max_Phys_Write_IO_per_Sec,
       MAX(Begin_Time) KEEP (DENSE_RANK LAST ORDER BY Phys_Write_IO_per_Sec)       Max_Write_IO_per_Sec_BeginTime,
       MAX((End_Time-Begin_Time)*1440) KEEP (DENSE_RANK LAST ORDER BY Phys_Write_IO_per_Sec) Cycle_Minutes_3,  
       MAX(Phys_Read_IO_per_Sec)                                                   Max_Phys_Read_IO_per_Sec,
       MAX(Begin_Time) KEEP (DENSE_RANK LAST ORDER BY Phys_Read_IO_per_Sec)        Max_Read_IO_per_Sec_BeginTime, 
       MAX((End_Time-Begin_Time)*1440) KEEP (DENSE_RANK LAST ORDER BY Phys_Read_IO_per_Sec) Cycle_Minutes_4,  
       MAX(Host_CPU_Utilization_Pct)                                               Max_Host_CPU_Utilization_Pct,
       MAX(Begin_Time) KEEP (DENSE_RANK LAST ORDER BY Host_CPU_Utilization_Pct)    Max_Host_CPU_Pct_BeginTime, 
       MAX((End_Time-Begin_Time)*1440) KEEP (DENSE_RANK LAST ORDER BY Host_CPU_Utilization_Pct) Cycle_Minutes_4,  
       MAX(DB_CPUs)                                                                Max_DB_CPUs,
       MAX(Begin_Time) KEEP (DENSE_RANK LAST ORDER BY DB_CPUs)                     DB_CPUs_BeginTime, 
       MAX((End_Time-Begin_Time)*1440) KEEP (DENSE_RANK LAST ORDER BY DB_CPUs)     Cycle_Minutes_4  
FROM   ( 
        SELECT /*+ NO_MERGE LEADING(h.ash) PARALLEL(h,4) */ 
               Instance_Number, Begin_Time, End_Time,
               ROUND(SUM(CASE WHEN Metric_Name = 'Physical Write Total Bytes Per Sec' THEN Average ELSE 0 END)/1024) Phys_Write_Total_kB_per_Sec,
               ROUND(SUM(CASE WHEN Metric_Name = 'Physical Read Total Bytes Per Sec'  THEN Average ELSE 0 END)/1024)  Phys_Read_Total_kB_per_Sec,
               ROUND(SUM(CASE WHEN Metric_Name = 'Physical Write IO Requests Per Sec' THEN Average ELSE 0 END)) Phys_Write_IO_per_Sec,
               ROUND(SUM(CASE WHEN Metric_Name = 'Physical Read IO Requests Per Sec'  THEN Average ELSE 0 END))  Phys_Read_IO_per_Sec,
               ROUND(SUM(CASE WHEN Metric_Name = 'Host CPU Utilization (%)'           THEN Average ELSE 0 END))  Host_CPU_Utilization_Pct,
               ROUND(SUM(CASE WHEN Metric_Name = 'CPU Usage Per Sec'                  THEN Average ELSE 0 END)/100,2)  DB_CPUs
        FROM   DBA_Hist_SysMetric_Summary
        WHERE  Begin_Time > SYSTIMESTAMP - 7
        AND    Metric_Name IN ('Physical Write Total Bytes Per Sec', 'Physical Write IO Requests Per Sec', 'Physical Read Total Bytes Per Sec', 'Physical Read IO Requests Per Sec',
                               'Host CPU Utilization (%)', 'CPU Usage Per Sec' )
        GROUP BY Instance_Number, Begin_Time, End_Time
       ) h
GROUP BY Instance_Number       
;