flashback drop 闪回下降（删除）
SQL> show parameter recyclebin
SQL> purge recyclebin;（清除回收站）
SQL> create tablespace tbs01 datafile '/home/oracle/tbs01.dbf' size 5M;
SQL> create table t1 tablespace tbs01 as select * from dba_objects where rownum<=20000;
SQL> create index t1_object_id_idx on t1(object_id) tablespace tbs01;
SQL> select INDEX_NAME from user_indexes where TABLE_NAME='T1';
SQL> drop table t1;
SQL> select table_name from user_tables;
SQL> show recyclebin
SQL> select object_name, original_name, type, droptime from user_recyclebin; 包含index
SQL> select count(*) from "BIN$IyKOcy5jPo7gUwEAqMCBEg==$0";
SQL> flashback table t1 to before drop;
SQL> select INDEX_NAME from user_indexes where TABLE_NAME='T1';
SQL> alter index "BIN$LRyc7hA1JaPgUwEAqMDzWw==$0" rename to T1_OBJECT_ID_IDX; 恢复index名称
重名的处理：
SQL> flashback table "BIN$IyKOcy5jPo7gUwEAqMCBEg==$0" to before drop;
SQL> flashback table t1 to before drop rename to t2;
SQL> drop table t1;
SQL> show recyclebin 在回收站中
SQL> create table t2 tablespace tbs01 as select * from dba_objects where rownum<=30000;
SQL> show recyclebin t1被覆盖
SQL> drop table t2 purge;
SQL> purge recyclebin
flashback transaction query(闪回事务查询)
SQL> alter database add supplemental log data;
SQL> alter database add supplemental log data (primary key) columns;
SQL> create table t1(x int);
SQL> insert into t1 values (1);
SQL> commit;
SQL> update t1 set x=11 where x=1; 误操作的事务
SQL> commit;
SQL> insert into t1 values (2);
SQL> commit;
select versions_starttime, versions_endtime, versions_xid, versions_operation, x
from t1
versions between scn minvalue and maxvalue
order by versions_starttime; 获取误操作事务的xid
SQL> select UNDO_SQL, OPERATION from flashback_transaction_query where xid='02000F0059040000';
flashback database（闪回数据库）
SQL> shutdown immediate
SQL> startup mount
SQL> alter database flashback on; 数据库在归档模式下
SQL> show parameter db_flashback_retention_target
SQL> select OLDEST_FLASHBACK_TIME from v$flashback_database_log;
SQL> create table t1(x int);
SQL> insert into t1 values (1);
SQL> commit;
SQL> select dbms_flashback.get_system_change_number from dual;
SQL> truncate table t1;
SQL> create table after_truncate(x int); 其他正确操作
SQL> select OLDEST_FLASHBACK_TIME, OLDEST_FLASHBACK_SCN from v$flashback_database_log; 确认是否在恢复范围
SQL> shutdown abort
SQL> startup mount
SQL> flashback database to scn 1495195;
SQL> alter database open resetlogs;
SQL> select * from t1;
SQL> select * from after_truncate; 消失
移动数据
sqlloader
SQL> create table t1(id int constraint t1_id_pk primary key, name varchar2(20), salary int constraint t1_salary_ck check(salary>0));
$ vi ~/loader.dat
100,"abc",1000
100,"def",2000
102,"xyz",-1000
em中常规导入，自动处理违反约束的记录

em中直接导入
SQL> select CONSTRAINT_NAME, STATUS from user_constraints where TABLE_NAME='T1';
SQL> select INDEX_NAME, STATUS from user_indexes where TABLE_NAME='T1';
SQL> alter table t1 enable validate constraint T1_SALARY_CK; 失败
SQL> @?/rdbms/admin/utlexpt1.sql
处理check约束：
SQL> alter table t1 enable validate constraint T1_SALARY_CK exceptions into exceptions;
SQL> select * from t1 where rowid in(select ROW_ID from exceptions);
SQL> update t1 set salary=abs(salary) where id=102;
SQL> truncate table exceptions;
SQL> alter table t1 enable validate constraint T1_SALARY_CK exceptions into exceptions;
处理pk约束：
SQL> alter table t1 disable novalidate constraint T1_ID_PK;
SQL> alter table t1 enable validate constraint T1_ID_PK exceptions into exceptions;
SQL> select * from t1 where rowid in(select ROW_ID from exceptions);
SQL> update t1 set id=101 where name='def';
SQL> truncate table exceptions;
SQL> alter table t1 enable validate constraint T1_ID_PK exceptions into exceptions;
SQL> select INDEX_NAME, STATUS from user_indexes where TABLE_NAME='T1';