V$FLASHBACK_DATABASE_LOG displays information about the flashback data. Use this view to help estimate the amount of flashback space required for the current workload.
| Column | Datatype | Description | 
|---|---|---|
| OLDEST_FLASHBACK_SCN | NUMBER | Lowest system change number (SCN) in the flashback data, for any incarnation | 
| OLDEST_FLASHBACK_TIME | DATE | Time of the lowest SCN in the flashback data, for any incarnation | 
| RETENTION_TARGET | NUMBER | Target retention time (in minutes) | 
| FLASHBACK_SIZE | NUMBER | Current size (in bytes) of the flashback data | 
| ESTIMATED_FLASHBACK_SIZE | NUMBER | Estimated size of flashback data needed for the current target retention |