不小心delete掉一些数据，而且已经commit了，怎么办？我们可以基于回闪（flashback）和scn进行一些数据的恢复。
--查询当前scn SQL> select dbms_flashback.get_system_change_number from dual; GET_SYSTEM_CHANGE_NUMBER ------------------------ 4787371 SQL> SELECT COUNT(*) FROM hjm_tb_test01; COUNT(*) ---------- 10072 --模拟误删除数据： SQL> delete from hjm_tb_test01 where object_id<=5000; 已删除4940行。 SQL> commit; 提交完成。 --删除数据后只有5132行了，原为10072行 SQL> SELECT COUNT(*) FROM hjm_tb_test01; COUNT(*) ---------- 5132 --创建用于恢复的表，将恢复数据插入其中 SQL> create table hjm_tb_test01_recov as select * from hjm_tb_test01 where 1=0; 表已创建。 SQL> select dbms_flashback.get_system_change_number from dual; GET_SYSTEM_CHANGE_NUMBER ------------------------ 4788873 SQL> select count(*) from hjm_tb_test01 as of scn &scn; 输入 scn 的值: 4788873 原值 1: select count(*) from hjm_tb_test01 as of scn &scn 新值 1: select count(*) from hjm_tb_test01 as of scn 4788873 COUNT(*) ---------- 5132 SQL> / 输入 scn 的值: 4787873 原值 1: select count(*) from hjm_tb_test01 as of scn &scn 新值 1: select count(*) from hjm_tb_test01 as of scn 4787873 COUNT(*) ---------- 10072 SQL> / 输入 scn 的值: 4788872 原值 1: select count(*) from hjm_tb_test01 as of scn &scn 新值 1: select count(*) from hjm_tb_test01 as of scn 4788872 COUNT(*) ---------- 5132 SQL> / 输入 scn 的值: 4788772 原值 1: select count(*) from hjm_tb_test01 as of scn &scn 新值 1: select count(*) from hjm_tb_test01 as of scn 4788772 COUNT(*) ---------- 5132 SQL> / 输入 scn 的值: 4787972 原值 1: select count(*) from hjm_tb_test01 as of scn &scn 新值 1: select count(*) from hjm_tb_test01 as of scn 4787972 COUNT(*) ---------- 10072 SQL> / 输入 scn 的值: 4788072 原值 1: select count(*) from hjm_tb_test01 as of scn &scn 新值 1: select count(*) from hjm_tb_test01 as of scn 4788072 COUNT(*) ---------- 10072 SQL> SQL> / 输入 scn 的值: 4788999 原值 1: select count(*) from hjm_tb_test01 as of scn &scn 新值 1: select count(*) from hjm_tb_test01 as of scn 4788999 COUNT(*) ---------- 5132 SQL> / 输入 scn 的值: 4788500 原值 1: select count(*) from hjm_tb_test01 as of scn &scn 新值 1: select count(*) from hjm_tb_test01 as of scn 4788500 COUNT(*) ---------- 5132 SQL> / 输入 scn 的值: 4788700 原值 1: select count(*) from hjm_tb_test01 as of scn &scn 新值 1: select count(*) from hjm_tb_test01 as of scn 4788700 COUNT(*) ---------- 5132 SQL> / 输入 scn 的值: 4788800 原值 1: select count(*) from hjm_tb_test01 as of scn &scn 新值 1: select count(*) from hjm_tb_test01 as of scn 4788800 COUNT(*) ---------- 5132 SQL> / 输入 scn 的值: 4788900 原值 1: select count(*) from hjm_tb_test01 as of scn &scn 新值 1: select count(*) from hjm_tb_test01 as of scn 4788900 COUNT(*) ---------- 5132 SQL> / 输入 scn 的值: 4788950 原值 1: select count(*) from hjm_tb_test01 as of scn &scn 新值 1: select count(*) from hjm_tb_test01 as of scn 4788950 COUNT(*) ---------- 5132 SQL> / 输入 scn 的值: 4788990 原值 1: select count(*) from hjm_tb_test01 as of scn &scn 新值 1: select count(*) from hjm_tb_test01 as of scn 4788990 COUNT(*) ---------- 5132 SQL> / 输入 scn 的值: 4788995 原值 1: select count(*) from hjm_tb_test01 as of scn &scn 新值 1: select count(*) from hjm_tb_test01 as of scn 4788995 COUNT(*) ---------- 5132 SQL> / 输入 scn 的值: 4788998 原值 1: select count(*) from hjm_tb_test01 as of scn &scn 新值 1: select count(*) from hjm_tb_test01 as of scn 4788998 COUNT(*) ---------- 5132 SQL> / 输入 scn 的值: 4788999 原值 1: select count(*) from hjm_tb_test01 as of scn &scn 新值 1: select count(*) from hjm_tb_test01 as of scn 4788999 COUNT(*) ---------- 5132 SQL> / 输入 scn 的值: 4788572 原值 1: select count(*) from hjm_tb_test01 as of scn &scn 新值 1: select count(*) from hjm_tb_test01 as of scn 4788572 COUNT(*) ---------- 5132 SQL> / 输入 scn 的值: 4788200 原值 1: select count(*) from hjm_tb_test01 as of scn &scn 新值 1: select count(*) from hjm_tb_test01 as of scn 4788200 COUNT(*) ---------- 10072 SQL> / 输入 scn 的值: 4788300 原值 1: select count(*) from hjm_tb_test01 as of scn &scn 新值 1: select count(*) from hjm_tb_test01 as of scn 4788300 COUNT(*) ---------- 10072 SQL> / 输入 scn 的值: 4788400 原值 1: select count(*) from hjm_tb_test01 as of scn &scn 新值 1: select count(*) from hjm_tb_test01 as of scn 4788400 COUNT(*) ---------- 5132 SQL> / 输入 scn 的值: 4788350 原值 1: select count(*) from hjm_tb_test01 as of scn &scn 新值 1: select count(*) from hjm_tb_test01 as of scn 4788350 COUNT(*) ---------- 10072 SQL> insert into hjm_tb_test01_recov select * from hjm_tb_test01 as of scn 4788350; 已创建10072行。 SQL> commit; 提交完成。 SQL>