Estimate flashback destination size
Estimate flashback destination size
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.
Method to estimate flashback space :
-
- Check the archive generation size via below query
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');
- Take the average per day size of archives generated
- Multiply the average archive size with x number of days
- Then add the required space for flashback file system.
