查看快速恢复区；

centos@SYS> show parameter db_recovery_file_dest
NAME                                        TYPE  VALUE
------------------------------------ -----------  ------------------------------
db_recovery_file_dest                     string  /u01/app/oracle/flash
db_recovery_file_dest_size           big integer  2G
centos@SYS>

修改快速恢复区路径：alter system set db_recovery_file_dest='指定路径';

修改快速恢复区大小；

centos@SYS> alter system set db_recovery_file_dest_size=3G;
System altered.
centos@SYS> show parameter db_recovery_file_dest
NAME                                        TYPE  VALUE
------------------------------------ -----------  ------------------------------
db_recovery_file_dest                     string  /u01/app/oracle/flash
db_recovery_file_dest_size           big integer  3G
centos@SYS>