V$FLASHBACK_DATABASE_LOG

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 (in bytes) for the current target retention
CON_ID	NUMBER	The ID of the container to which the data pertains. Possible values include: 0: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs. 1: This value is used for rows containing data that pertain to only the root n: Where n is the applicable container ID for the rows containing data