Track Amount of Redo Generation

select trunc(completion_time) rundate
,count(*)  logswitch
,round((sum(blocks*block_size)/1024/1024/1024)) "REDO PER DAY (GB)"
from v$archived_log
group by trunc(completion_time)
order by 1;


SELECT  Start_Date,   Start_Time,   Num_Logs,
Round(Num_Logs * (Vl.Bytes / (1024 * 1024)),2) AS Mbytes, Vdb.NAME AS Dbname
FROM (SELECT To_Char(Vlh.First_Time, 'YYYY-MM-DD') AS Start_Date,
To_Char(Vlh.First_Time, 'HH24') || ':00' AS Start_Time, COUNT(Vlh.Thread#) Num_Logs
FROM V$log_History Vlh 
GROUP BY To_Char(Vlh.First_Time,  'YYYY-MM-DD'),
To_Char(Vlh.First_Time, 'HH24') || ':00') Log_Hist,
V$log Vl ,  V$database Vdb
WHERE Vl.Group# = 1
ORDER BY Log_Hist.Start_Date, Log_Hist.Start_Time;