自己积累的表、数据恢复。

alter table tablename enable row movement;
flashback table name to timestamp(systimestamp - interval '50' minute);   
--或
select *from ch_settle_app as of timestamp to_timestamp ('04/19/2011 00:00:00','mm/dd/yyyy hh24:mi:ss');   
-----恢复drop掉的表：
SELECT * FROM user_recyclebin WHERE original_name=upper('group_customer');
方法1.FLASHBACK TABLE GROUP_CUSTOMER TO BEFORE DROP RENAME TO GROUP_CUSTOMER_aa;
方法2.flashback table "BIN$wlVv6h+IINDgQwomyh8g0A==$0" to before drop;此句与上一句的作用是一样的，都是恢复表

select * from recyclebin

----oracle中取一个随机值
select dbms_random.value from dual;
select dbms_random.value(0,1) from dual;