How to eastimating size of Flash Recovery Area for Flashback Logs?

SQL> SELECT ESTIMATED_FLASHBACK_SIZE FROM V$FLASHBACK_DATABASE_LOG;

This Query will return an estimate disk space (needed) for current flashback retation target.

This will be based on the database workload since Flashback Database was enabled.

How to determine earliest point in time to which can actually rewind your

database?

SQL>SELECT OLDEST_FLASHBACK_SCN,OLDEST_FLASHBACK_TIME FROM V$FLASHBACK_DATABASE_LOG;

Monitor logging in the Flashback Database logs?

SQL>select begin_time, flashback_data, db_data, redo_data, ESTIMATED_FLASHBACK_SIZE from v$flashback_database_stat;

Monitor the Flashback Database retention target?

select * from v$flashback_database_log;