oracle flashback 闪回 误删数据

1、闪回到undo空间允许的时间戳：

FlashBack table materials to timestamp to_timestamp('2023-05-16 18:40:00','yyyy-mm-dd hh24:mi:ss');

2、查询某表undo空间允许的时间戳：

select * from materials as of timestamp to_timestamp('2023-05-16 18:12:11','yyyy-mm-dd hh24:mi:ss') where id ='1';

3、恢复某一行数据到某表

insert into  materials select * from materials as of timestamp to_timestamp('2023-05-16 18:12:11','yyyy-mm-dd hh24:mi:ss');

4、知道scn时

select dbms_flashback.get_system_change_number scn from dual; --5192495

select * from materials as of scn 5173163 where id=858;