Sometimes we need to enable flashback for x number of days. In such case, we need to estimate the flashback space required for x number of days in order to store the flashback logs.
Note : The flashback log size is same as archive log size generated in a database.
select to_char(COMPLETION_TIME,'DD-MON-YYYY') Arch_Date,count(*) No#_Logs, sum((BLOCKS*512)/1024/1024/1024) Arch_LogSize_GB from v$archived_log where to_char(COMPLETION_TIME,'DD-MON-YYYY')>=trunc(sysdate-7) and DEST_ID=1 group by to_char(COMPLETION_TIME,'DD-MON-YYYY') order by to_char(COMPLETION_TIME,'DD-MON-YYYY');