Oracle Database Discussions

Hello: I have this in my DB:

SQL> archive log list
Database log mode Archive Mode
Automatic archival Enabled
Archive destination USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence 7474
Next log sequence to archive 7476
Current log sequence 7476
SQL> show parameter db_recovery;

NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_recovery_file_dest string /opt/oracle/backups/flash_recovery_area
db_recovery_file_dest_size big integer 100G

SQL> select space_used/(1024*1024),space_limit/(1024*1024) from v$recovery_file_dest;

SPACE_USED/(1024*1024) SPACE_LIMIT/(1024*1024)
---------------------- -----------------------
199.989746 102400

SQL> select estimated_flashback_size, flashback_size, oldest_flashback_scn, oldest_flashback_time from v$flashback_database_log;

no rows selected

SQL> select * from v$flashback_database_stat ;

no rows selected


My question is : The values showed from v$recovery_file_dest are enough to decrease the size of the flsh recovery area, or should i see anything else. What is the best procedure to decrease the size without stop the DB ?

Thanks in advance by your help