19c administration for enabling flashback on

check if archive destination has enough space

sqlplus "/as sysdba"

SQL> alter system set db_recovery_file_dest_size=10G scope=both sid=’*’;

System altered.

SQL> alter system set db_recovery_file_dest=’+DATA_01’ scope=both sid=’*’;

System altered.

SQL> alter database flashback on;

Database altered.

restart the database;

SQL> select log_mode,flashback_on from v$database;

LOG_MODE FLASHBACK_ON

———— ——————

ARCHIVELOG YES

Best wishes