db_recovery_file_dest_size大小查看，修改

SQL> show parameter db_recover;

NAME                                 TYPE
------------------------------------ ----------------------
VALUE
------------------------------
db_recovery_file_dest                string
/opt/oracle/flash_recovery_are
a
db_recovery_file_dest_size           big integer
20G

修改db_recovery_file_dest_size大小为500G

alter system set db_recovery_file_dest_size=500G scope=spfile(需要重启DB生效)