那边就不做牵线,本文首要对Oracle常用闪回使用做些详细介绍

三、备注
1、相关数据字典
V$FLASHBACK_DATABASE_LOG ##翻开数据库可闪回的时光点/SCN等信息
V$flashback_database_stat ##查阅闪回日志空间记录音信
2、常用查询语句
(1)查看数据库状态

备考:就算不初步flashback,只要打开了recyclebin,那么就足以闪回DROP表。

一、Oracle闪回概述

select scn, STORAGE_SIZE ,to_char(time,'yyyy-mm-dd hh24:mi:ss') time,NAME from v$restore_point;

但即使老是覆盖,就需求指定復苏的表名,如若已经存在表,则须要还原重命名。

(3)开启闪回

  

(2)获取当前数据库的连串时间和SCN

 

SQL> show recyclebin;
ORIGINAL NAME RECYCLEBIN NAME OBJECT TYPE DROP TIME
---------------- ------------------------------ ------------ -------------------
T BIN$YEh2QcvddJLgUxyAgQpnVQ==$0 TABLE 2017-12-14:15:07:54
T BIN$YEh2QcvcdJLgUxyAgQpnVQ==$0 TABLE 2017-12-14:15:07:27
SQL> flashback table "BIN$YEh2QcvcdJLgUxyAgQpnVQ==$0" to before drop ;
Flashback complete.
SQL> show recyclebin;
ORIGINAL NAME RECYCLEBIN NAME OBJECT TYPE DROP TIME
---------------- ------------------------------ ------------ -------------------
T BIN$YEh2QcvddJLgUxyAgQpnVQ==$0 TABLE 2017-12-14:15:07:54
SQL> flashback table t to before drop rename to tt;
Flashback complete.

a.闪回数据库
  FLASHBACK DATABASE TO TIMESTAMP to_timestamp(‘2017-12-14
14:28:33′,’yyyy-mm-dd HH24:MI:SS’);;
  flashback database to scn 16813234;
b.闪回DROP
其中table_name可以是去除表名称,也可以是别名
  flashback table table_name to before drop;
  flashback table table_name to before drop rename to
table_name_new;
c.闪回表
  flashback table table_name to scn scn_number;
  flashback table table_name to timestamp to_timestamp(‘2017-12-14
14:28:33′,’yyyy-mm-dd hh24:mi:ss’);
d.闪回查询
  select * from table_name as of timestamp to_timestamp(‘2017-12-14
14:28:33′,’yyyy-mm-dd hh24:mi:ss’);
  select * from scott.dept as of scn 16801523;

(5)关闭闪回

SQL> select flashback_on from v$database;
FLASHBACK_ON
------------------
YES    

 

SQL> select NAME,OPEN_MODE ,DATABASE_ROLE,CURRENT_SCN,FLASHBACK_ON from v$database;

NAME OPEN_MODE DATABASE_ROLE CURRENT_SCN FLASHBACK_ON
------------- -------------------- ---------------- ----------- ------------------
TESTDB READ WRITE PRIMARY 16812246 YES

数据库闪回必须在mounted状态下开展,基于快照的可以再open下展开闪回库
闪回数据库重点是将数据库还原值过去的某个时间点或SCN,用于数据库出现逻辑错误时,需求open
database resetlogs
a.全库闪回
数据库闪回示例

2、闪回使用

SQL> select * from scott.EMP;

EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
---------- ---------- --------- ---------- ------------------- ---------- ---------- ----------
7369 SMITH CLERK 7902 1980-12-17 00:00:00 800 20
7499 ALLEN SALESMAN 7698 1981-02-20 00:00:00 1600 300 30
7521 WARD SALESMAN 7698 1981-02-22 00:00:00 1250 500 30
7566 JONES MANAGER 7839 1981-04-02 00:00:00 2975 20
7654 MARTIN SALESMAN 7698 1981-09-28 00:00:00 1250 1400 30
7698 BLAKE MANAGER 7839 1981-05-01 00:00:00 2850 30
7782 CLARK MANAGER 7839 1981-06-09 00:00:00 2450 10
7788 SCOTT ANALYST 7566 1987-04-19 00:00:00 3000 20
7839 KING PRESIDENT 1981-11-17 00:00:00 5000 10
7844 TURNER SALESMAN 7698 1981-09-08 00:00:00 1500 0 30
7876 ADAMS CLERK 7788 1987-05-23 00:00:00 1100 20
7900 JAMES CLERK 7698 1981-12-03 00:00:00 950 30
7902 FORD ANALYST 7566 1981-12-03 00:00:00 3000 20
7934 MILLER CLERK 7782 1982-01-23 00:00:00 1300 10

14 rows selected.

SQL> truncate table scott.EMP;

Table truncated.
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount;
ORACLE instance started.

Total System Global Area 9.4067E+10 bytes
Fixed Size 2263936 bytes
Variable Size 9395242112 bytes
Database Buffers 8.4557E+10 bytes
Redo Buffers 112766976 bytes
Database mounted.
SQL> flashback database to timestamp to_timestamp('2017-12-14 14:12:46','yyyy-mm-dd HH24:MI:SS');

Flashback complete.
SQL> alter database open resetlogs;

Database altered.

SQL> select * from scott.emp;

EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
---------- ---------- --------- ---------- ------------------- ---------- ---------- ----------
7369 SMITH CLERK 7902 1980-12-17 00:00:00 800 20
7499 ALLEN SALESMAN 7698 1981-02-20 00:00:00 1600 300 30
7521 WARD SALESMAN 7698 1981-02-22 00:00:00 1250 500 30
7566 JONES MANAGER 7839 1981-04-02 00:00:00 2975 20
7654 MARTIN SALESMAN 7698 1981-09-28 00:00:00 1250 1400 30
7698 BLAKE MANAGER 7839 1981-05-01 00:00:00 2850 30
7782 CLARK MANAGER 7839 1981-06-09 00:00:00 2450 10
7788 SCOTT ANALYST 7566 1987-04-19 00:00:00 3000 20
7839 KING PRESIDENT 1981-11-17 00:00:00 5000 10
7844 TURNER SALESMAN 7698 1981-09-08 00:00:00 1500 0 30
7876 ADAMS CLERK 7788 1987-05-23 00:00:00 1100 20
7900 JAMES CLERK 7698 1981-12-03 00:00:00 950 30
7902 FORD ANALYST 7566 1981-12-03 00:00:00 3000 20
7934 MILLER CLERK 7782 1982-01-23 00:00:00 1300 10

14 rows selected.

b.闪回版本查询

(4)确定闪回开启

用来查询行级数据库随时间变化的点子

2、闪回使用

SQL> select flashback_on from v$database;
FLASHBACK_ON
------------------
NO

用来查询行级数据库随时间变化的措施

db_recovery_file_dest:指定闪回过来区的岗位
db_recovery_file_dest_size:指定闪回过来区的可用空间尺寸
db_flashback_retention_target:指定数据库可以回退的日子,单位为分钟,默许1440分钟(1天),实际取决于闪回区大小
(2)检查是或不是开启闪回

SQL> alter system set db_recovery_file_dest='/home/U01/app/oracle/fast_recovery_area' scope=both;
System altered.
SQL> alter system set db_recovery_file_dest_size=60G scope=both;
System altered.
SQL> alter system set db_flashback_retention_target=4320 scope=both;
System altered.    

Oracle 9i
早先援救闪回,Oracle10g起来周到协理闪回功用,Oracle11g有所完善,为大家很快的回涨数据,查询历史数据提供了很大的便民方式。

1、闪回开启
(1)开启闪回需求条件
a.开启归档日志

SQL> select to_char(systimestamp,'yyyy-mm-dd HH24:MI:SS') as sysdt , dbms_flashback.get_system_change_number scn from dual;

SYSDT SCN
------------------- ----------
2017-12-14 14:28:33 16813234
SQL> flashback table scott.dept to timestamp to_timestamp('2017-12-14 16:20:00','yyyy-mm-dd hh24:mi:ss');
flashback table scott.dept to timestamp to_timestamp('2017-12-14 16:20:00','yyyy-mm-dd hh24:mi:ss')
ERROR at line 1:
ORA-08189: cannot flashback the table because row movement is not enabled

SQL> select row_movement from dba_tables where table_name='DEPT' and owner='SCOTT';
ROW_MOVE
--------
DISABLED
SQL> alter table scott.dept enable row movement;
Table altered.

SQL> flashback table scott.dept to timestamp to_timestamp('2017-12-14 16:20:00','yyyy-mm-dd hh24:mi:ss');
Flashback complete.
SQL> select * from scott.dept;
DEPTNO DNAME LOC
---------- -------------- -------------
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON    
SQL> alter table scott.dept disable row movement;
Table altered.

 c.闪回snapshot standby

SQL> select * from V$FLASHBACK_DATABASE_LOG;

OLDEST_FLASHBACK_SCN OLDEST_FLASHBACK_TI RETENTION_TARGET FLASHBACK_SIZE ESTIMATED_FLASHBACK_SIZE
-------------------- ------------------- ---------------- -------------- ------------------------
16801523 2017-12-14 11:35:05 4320 104857600 244113408

 

a.开启归档

SQL> alter database flashback on;
Database altered.
SQL> select * from scott.dept;
DEPTNO DNAME LOC
---------- -------------- -------------
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON
SQL> delete from scott.dept where deptno=40;
1 row deleted.
SQL> commit;
Commit complete.
SQL> select * from scott.dept as of timestamp sysdate-10/1440;

DEPTNO DNAME LOC
---------- -------------- -------------
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON
SQL> select * from scott.dept as of timestamp to_timestamp('2017-12-14 16:20:00','yyyy-mm-dd hh24:mi:ss');

DEPTNO DNAME LOC
---------- -------------- -------------
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON

SQL> select * from scott.dept as of scn 16801523;

DEPTNO DNAME LOC
---------- -------------- -------------
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON

b.设置合理的闪回区

3、闪回注意事项
(1)数据库闪回必要在mounted下进行,并且open时索要利用resetlogs
(2)闪回DROP只可以用于非系统表空间和本地管理的表空间,外键约束无法苏醒,对方覆盖、重命名需注意
(3)表DROP,对应的物化视图会被彻底剔除,物化视图不会存放在recyclebin里
(4)闪回表,若是在做过dml,然后举行了表结构修改、truncate等DDL操作,新增/删除结构不可以做闪回
(5)闪回归档,必须在assm管理tablespace和undo auto管理下展开
(6)注意闪回区管理,幸免磁盘爆满,闪回区空间不足等

当一个表被drop掉,表会被放入recyclebin回收站,可通过回收站做表的闪回。表上的目录、约束等同样会被还原
不协理sys/system用户表空间对象,可通过alter system set
recyclebin=off;关闭回收站功用
闪回DROP示例:

 二、Oracle闪回使用详解

正文主要对Oracle常用闪回使用做些详细介绍,其中对于不常用的事体和本子闪回,那里就不做牵线

 

SQL> flashback table scott.dept to timestamp to_timestamp('2017-12-14 16:20:00','yyyy-mm-dd hh24:mi:ss');
flashback table scott.dept to timestamp to_timestamp('2017-12-14 16:20:00','yyyy-mm-dd hh24:mi:ss')
ERROR at line 1:
ORA-08189: cannot flashback the table because row movement is not enabled

SQL> select row_movement from dba_tables where table_name='DEPT' and owner='SCOTT';
ROW_MOVE
--------
DISABLED
SQL> alter table scott.dept enable row movement;
Table altered.

SQL> flashback table scott.dept to timestamp to_timestamp('2017-12-14 16:20:00','yyyy-mm-dd hh24:mi:ss');
Flashback complete.
SQL> select * from scott.dept;
DEPTNO DNAME LOC
---------- -------------- -------------
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON    
SQL> alter table scott.dept disable row movement;
Table altered.

 c.闪回snapshot standby

 

SQL> select * from V$flashback_database_stat;
BEGIN_TIME END_TIME FLASHBACK_DATA DB_DATA REDO_DATA ESTIMATED_FLASHBACK_SIZE
------------------- ------------------- -------------- ---------- ---------- ------------------------
2017-12-14 14:34:53 2017-12-14 14:56:43 1703936 9977856 1487872 0    

e.闪回快照

  

数据库闪回必须在mounted状态下展开,基于快照的可以再open下举行闪回库
闪回数据库重点是将数据库还原值过去的某部时刻点或SCN,用于数据库出现逻辑错误时,须求open
database resetlogs
a.全库闪回
数据库闪回示例

Oracle 9i
初阶支持闪回,Oracle10g开班周到支持闪回功效,Oracle11g有所完善,为大家快捷的东山再起数据,查询历史数据提供了很大的便利措施。

(4)确定闪回开启

正文首要对Oracle常用闪回使用做些详细介绍,其中对于不常用的业务和本子闪回,那里就不做牵线

(4)查看闪回日志空间情状

c.闪回事情查询
用来提供查看工作级别数据库变化的办法

 针对主库和备库都足以制造闪回快照点,然后还原到指定的快照点,但主库一旦复苏到快照点,备库的联合则须要重新联合

(1)闪回查询
闪回查询重要是基于Undo表空间数据进行多版本查询,针对v$和x$动态品质视图无效,但对DBA_、ALL_、USER_是有效的
a.闪回查询
同意用户查询过去某个时间点的多寡,用以重构由于意外删除或转移的数据,数据不会生成。

 

 

(7)闪回语句

请参见我前边的和讯:http://blog.itpub.net/27067062/viewspace-2129130/

  create restore point before_201712151111 guarantee flashback
database;

 

select scn,to_char(time_dp,'yyyy-mm-dd hh24:mi:ss')from sys.smon_scn_time;

c.开启flashback (10g在mount开启)

SQL> show recyclebin;
ORIGINAL NAME RECYCLEBIN NAME OBJECT TYPE DROP TIME
---------------- ------------------------------ ------------ -------------------
T BIN$YEh2QcvddJLgUxyAgQpnVQ==$0 TABLE 2017-12-14:15:07:54
T BIN$YEh2QcvcdJLgUxyAgQpnVQ==$0 TABLE 2017-12-14:15:07:27
SQL> flashback table "BIN$YEh2QcvcdJLgUxyAgQpnVQ==$0" to before drop ;
Flashback complete.
SQL> show recyclebin;
ORIGINAL NAME RECYCLEBIN NAME OBJECT TYPE DROP TIME
---------------- ------------------------------ ------------ -------------------
T BIN$YEh2QcvddJLgUxyAgQpnVQ==$0 TABLE 2017-12-14:15:07:54
SQL> flashback table t to before drop rename to tt;
Flashback complete.
闪回级别 闪回场景 闪回技术 对象依赖   影响数据
数据库 表截断、逻辑错误、其他多表意外事件 闪回DATABASE 闪回日志、undo
DROP 删除表 闪回DROP 回收站(recyclebin)
更新、删除、插入记录 闪回TABLE 还原数据,undo
查询 当前数据和历史数据对比 闪回QUERY 还原数据,undo
版本查询 比较行版本 闪回Version Query 还原数据,undo
事务查询 比较 闪回Transaction Query 还原数据,undo
归档 DDL、DML 闪回Archive 归档日志
         

(2)获取当前数据库的连串时间和SCN

(4)闪回数据库(truncate/多表数据变动)

SQL> alter system set db_recovery_file_dest='/home/U01/app/oracle/fast_recovery_area' scope=both;
System altered.
SQL> alter system set db_recovery_file_dest_size=60G scope=both;
System altered.
SQL> alter system set db_flashback_retention_target=4320 scope=both;
System altered.    

(7)闪回语句

SQL> select * from V$FLASHBACK_DATABASE_LOG;

OLDEST_FLASHBACK_SCN OLDEST_FLASHBACK_TI RETENTION_TARGET FLASHBACK_SIZE ESTIMATED_FLASHBACK_SIZE
-------------------- ------------------- ---------------- -------------- ------------------------
16801523 2017-12-14 11:35:05 4320 104857600 244113408

(3)查看数据库可过来的小时点

SQL> select * from t ;

ID NAME
---------- ---------------------------------------
1
2
3
4
30

SQL> drop table t;

Table dropped.

SQL> show recyclebin;
ORIGINAL NAME RECYCLEBIN NAME OBJECT TYPE DROP TIME
---------------- ------------------------------ ------------ -------------------
T BIN$YEh2QcvZdJLgUxyAgQpnVQ==$0 TABLE 2017-12-14:15:02:06
SQL> flashback table t to before drop;

Flashback complete.

SQL> select * from t;

ID NAME
---------- -------------------------------------
1
2
3
4
30    
SQL> select to_char(systimestamp,'yyyy-mm-dd HH24:MI:SS') as sysdt , dbms_flashback.get_system_change_number scn from dual;

SYSDT SCN
------------------- ----------
2017-12-14 14:28:33 16813234

 二、Oracle闪回使用详解

b.设置闪回区

select scn, STORAGE_SIZE ,to_char(time,'yyyy-mm-dd hh24:mi:ss') time,NAME from v$restore_point;
SQL> select * from scott.dept;

    DEPTNO DNAME          LOC           ADDR
---------- -------------- ------------- ------------------------------
        10 ACCOUNTING     NEW YORK
        20 RESEARCH       DALLAS
        30 SALES          CHICAGO

SQL> create restore point before_201712151111 guarantee flashback database;
Restore point created.

SQL> create table scott.t as select * from scott.dept;
Table created.

SQL> truncate table scott.t;
Table truncated.
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount;
ORACLE instance started.

Total System Global Area 9.4067E+10 bytes
Fixed Size                  2263936 bytes
Variable Size            9663677568 bytes
Database Buffers         8.4289E+10 bytes
Redo Buffers              112766976 bytes
Database mounted.
SQL> flashback database to restore point before_201712151111;
Flashback complete.
SQL> alter database open resetlogs;
Database altered.

此时主库scott.t已不存在:
SQL> select * from scott.t;
select * from scott.t
                    *
ERROR at line 1:
ORA-00942: table or view does not exist
此时从库的scott.依旧存在,主备同步终止
解决方案:在主库创建快照时间点,从库自动停止应用日志,等主库闪回后,重新应用日志即可。
如果已经做了上述操作,从库可以选择重建
ALTER DATABASE REGISTER LOGFILE '/xx/xx/archive.dbf';

(7)闪回空间爆满难题处理

(2)闪回表(update/insert/delete)
闪回表就是对表的数据做回退,回退到事先的某个时间点,其选取的是undo的野史数据,与undo_retention设置有关,默许是14400分钟(1天)
一样,sys用户表空间不辅助闪回表,要想表闪回,要求允许表启动行迁移(row
movement)
闪回表示例:

select scn, STORAGE_SIZE ,to_char(time,'yyyy-mm-dd hh24:mi:ss') time,NAME from v$restore_point;
select database_role,open_mode,db_unique_name,flashback_on from v$database;

SQL> set line 200;
SQL> set pagesize 2000;
SQL> select database_role,open_mode,db_unique_name,flashback_on from v$database;

DATABASE_ROLE    OPEN_MODE            DB_UNIQUE_NAME                 FLASHBACK_ON
---------------- -------------------- ------------------------------ ------------------
PHYSICAL STANDBY READ ONLY            testdbms                       NO


SQL> ALTER DATABASE CONVERT TO SNAPSHOT STANDBY;  

Database altered.

SQL> select database_role,open_mode,db_unique_name,flashback_on from v$database;

DATABASE_ROLE    OPEN_MODE            DB_UNIQUE_NAME                 FLASHBACK_ON
---------------- -------------------- ------------------------------ ------------------
SNAPSHOT STANDBY MOUNTED              testdbms                       RESTORE POINT ONLY

SQL> alter database open;

Database altered.

SQL> select open_mode from v$database;

OPEN_MODE
--------------------
READ WRITE


此时备库操作:
SQL> select * from scott.emp;

     EMPNO ENAME      JOB              MGR HIREDATE                   SAL       COMM     DEPTNO
---------- ---------- --------- ---------- ------------------- ---------- ---------- ----------
      7369 SMITH      CLERK           7902 1980-12-17 00:00:00        800                    20
      7499 ALLEN      SALESMAN        7698 1981-02-20 00:00:00       1600        300         30
      7521 WARD       SALESMAN        7698 1981-02-22 00:00:00       1250        500         30
      7566 JONES      MANAGER         7839 1981-04-02 00:00:00       2975                    20
      7654 MARTIN     SALESMAN        7698 1981-09-28 00:00:00       1250       1400         30
      7698 BLAKE      MANAGER         7839 1981-05-01 00:00:00       2850                    30
      7782 CLARK      MANAGER         7839 1981-06-09 00:00:00       2450                    10
      7788 SCOTT      ANALYST         7566 1987-04-19 00:00:00       3000                    20
      7839 KING       PRESIDENT            1981-11-17 00:00:00       5000                    10
      7844 TURNER     SALESMAN        7698 1981-09-08 00:00:00       1500          0         30
      7876 ADAMS      CLERK           7788 1987-05-23 00:00:00       1100                    20
      7900 JAMES      CLERK           7698 1981-12-03 00:00:00        950                    30
      7902 FORD       ANALYST         7566 1981-12-03 00:00:00       3000                    20
      7934 MILLER     CLERK           7782 1982-01-23 00:00:00       1300                    10

14 rows selected.

SQL> truncate table scott.emp;

Table truncated.

主库操作:
SQL> create table scott.t as select * from scott.dept;

Table created.

SQL> select * from scott.t;

    DEPTNO DNAME          LOC           ADDR
---------- -------------- ------------- ------------------------------
        10 ACCOUNTING     NEW YORK
        20 RESEARCH       DALLAS
        30 SALES          CHICAGO

备库恢复到物理standby
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount;
ORACLE instance started.

Total System Global Area 9.4067E+10 bytes
Fixed Size                  2263936 bytes
Variable Size            9663677568 bytes
Database Buffers         8.4289E+10 bytes
Redo Buffers              112766976 bytes
Database mounted.
SQL> ALTER DATABASE CONVERT TO PHYSICAL STANDBY; 

Database altered.
SQL> shutdown immediate;
ORA-01507: database not mounted


ORACLE instance shut down.
SQL> startup ;
ORACLE instance started.

Total System Global Area 9.4067E+10 bytes
Fixed Size                  2263936 bytes
Variable Size            9663677568 bytes
Database Buffers         8.4289E+10 bytes
Redo Buffers              112766976 bytes
Database mounted.
Database opened.

##此时备库的数据已经恢复到转变snapshot standby时间点
SQL> select database_role,open_mode,db_unique_name,flashback_on from v$database;

DATABASE_ROLE    OPEN_MODE            DB_UNIQUE_NAME                 FLASHBACK_ON
---------------- -------------------- ------------------------------ ------------------
PHYSICAL STANDBY READ ONLY            testdbms                       NO

SQL>  select * from scott.emp;

     EMPNO ENAME      JOB              MGR HIREDATE                   SAL       COMM     DEPTNO
---------- ---------- --------- ---------- ------------------- ---------- ---------- ----------
      7369 SMITH      CLERK           7902 1980-12-17 00:00:00        800                    20
      7499 ALLEN      SALESMAN        7698 1981-02-20 00:00:00       1600        300         30
      7521 WARD       SALESMAN        7698 1981-02-22 00:00:00       1250        500         30
      7566 JONES      MANAGER         7839 1981-04-02 00:00:00       2975                    20
      7654 MARTIN     SALESMAN        7698 1981-09-28 00:00:00       1250       1400         30
      7698 BLAKE      MANAGER         7839 1981-05-01 00:00:00       2850                    30
      7782 CLARK      MANAGER         7839 1981-06-09 00:00:00       2450                    10
      7788 SCOTT      ANALYST         7566 1987-04-19 00:00:00       3000                    20
      7839 KING       PRESIDENT            1981-11-17 00:00:00       5000                    10
      7844 TURNER     SALESMAN        7698 1981-09-08 00:00:00       1500          0         30
      7876 ADAMS      CLERK           7788 1987-05-23 00:00:00       1100                    20
      7900 JAMES      CLERK           7698 1981-12-03 00:00:00        950                    30
      7902 FORD       ANALYST         7566 1981-12-03 00:00:00       3000                    20
      7934 MILLER     CLERK           7782 1982-01-23 00:00:00       1300                    10

14 rows selected.


SQL> alter database recover managed standby database using current logfile disconnect;

Database altered.

SQL> select * from scott.t;

    DEPTNO DNAME          LOC           ADDR
---------- -------------- ------------- ------------------------------
        10 ACCOUNTING     NEW YORK
        20 RESEARCH       DALLAS
        30 SALES          CHICAGO


SQL>  select database_role,open_mode,db_unique_name,flashback_on from v$database;

DATABASE_ROLE    OPEN_MODE            DB_UNIQUE_NAME                 FLASHBACK_ON
---------------- -------------------- ------------------------------ ------------------
PHYSICAL STANDBY READ ONLY WITH APPLY testdbms                       NO
SQL> select * from t ;

ID NAME
---------- ---------------------------------------
1
2
3
4
30

SQL> drop table t;

Table dropped.

SQL> show recyclebin;
ORIGINAL NAME RECYCLEBIN NAME OBJECT TYPE DROP TIME
---------------- ------------------------------ ------------ -------------------
T BIN$YEh2QcvZdJLgUxyAgQpnVQ==$0 TABLE 2017-12-14:15:02:06
SQL> flashback table t to before drop;

Flashback complete.

SQL> select * from t;

ID NAME
---------- -------------------------------------
1
2
3
4
30    
SQL> archive log list;
Database log mode Archive Mode
Automatic archival Enabled
Archive destination /home/U01/app/oracle/oradata/testdb/arch
Oldest online log sequence 844
Next log sequence to archive 846
Current log sequence 846

##如未开启,在mount状态执行alter database archivelog;
SQL> select NAME,OPEN_MODE ,DATABASE_ROLE,CURRENT_SCN,FLASHBACK_ON from v$database;

NAME OPEN_MODE DATABASE_ROLE CURRENT_SCN FLASHBACK_ON
------------- -------------------- ---------------- ----------- ------------------
TESTDB READ WRITE PRIMARY 16812246 YES

 

b.设置合理的闪回区

c.闪回事情查询
用以提供查看工作级别数据库变化的办法

(3)闪回DROP(drop table)

(3)查看数据库可过来的光阴点

但即使一连覆盖,就要求指定恢复生机的表名,若是已经存在表,则要求还原重命名。

(6)查看闪回restore_point

  flashback database to restore point before_201712151111;

c.开启flashback (10g在mount开启)

b.快照闪回

1、闪回开启
(1)开启闪回需要条件
a.开启归档日志

 

a.开启归档

e.闪回快照

(2)闪回表(update/insert/delete)
闪回表就是对表的多寡做回退,回退到前边的某部时间点,其应用的是undo的历史数据,与undo_retention设置有关,默许是14400分钟(1天)
一致,sys用户表空间不协助闪回表,要想表闪回,须要允许表启动行迁移(row
movement)
闪回表示例:

(5)SCN和timestamp装换关系查询

SQL> select * from V$flashback_database_stat;
BEGIN_TIME END_TIME FLASHBACK_DATA DB_DATA REDO_DATA ESTIMATED_FLASHBACK_SIZE
------------------- ------------------- -------------- ---------- ---------- ------------------------
2017-12-14 14:34:53 2017-12-14 14:56:43 1703936 9977856 1487872 0    

(7)主库做库的闪回,会影响备库,需要再次联合
(8)snapshot standby 不帮助最高珍惜形式

 

a.闪回数据库
  FLASHBACK DATABASE TO TIMESTAMP to_timestamp(‘2017-12-14
14:28:33′,’yyyy-mm-dd HH24:MI:SS’);;
  flashback database to scn 16813234;
b.闪回DROP
其中table_name可以是去除表名称,也足以是别名
  flashback table table_name to before drop;
  flashback table table_name to before drop rename to
table_name_new;
c.闪回表
  flashback table table_name to scn scn_number;
  flashback table table_name to timestamp to_timestamp(‘2017-12-14
14:28:33′,’yyyy-mm-dd hh24:mi:ss’);
d.闪回查询
  select * from table_name as of timestamp to_timestamp(‘2017-12-14
14:28:33′,’yyyy-mm-dd hh24:mi:ss’);
  select * from scott.dept as of scn 16801523;

  flashback database to restore point before_201712151111;

SQL> alter database flashback off;
Database altered.

(4)闪回数据库(truncate/多表数据变动)

三、备注
1、相关数据字典
V$FLASHBACK_DATABASE_LOG ##查看数据库可闪回的光阴点/SCN等音信
V$flashback_database_stat ##翻看闪回日志空间记录音信
2、常用查询语句
(1)查看数据库状态

mount状态:alter database archivelog;

 

 

(7)闪回空间爆满难点处理

(5)闪回归档(增添、修改、重命名、删除表的列、truncate表、修改表的羁绊、以及修改分区表的分区规范)

此作用在11GR2相当实用,可自动创设闪回点、开启闪回日志,可成功线上数据测试后,然后做数据库闪回恢复生机主备关系

此效率在11GR2非常实用,可活动创造闪回点、开启闪回日志,可做到线上数据测试后,然后做数据库闪回苏醒主备关系

 

 

 

(7)主库做库的闪回,会影响备库,须要再行联合
(8)snapshot standby 不协理最高敬重方式

SQL> archive log list;
Database log mode Archive Mode
Automatic archival Enabled
Archive destination /home/U01/app/oracle/oradata/testdb/arch
Oldest online log sequence 844
Next log sequence to archive 846
Current log sequence 846

##如未开启,在mount状态执行alter database archivelog;

 

(5)闪回归档(伸张、修改、重命名、删除表的列、truncate表、修改表的封锁、以及修改分区表的分区规范)

备注:即便不开头flashback,只要打开了recyclebin,那么就可以闪回DROP表。

(6)查看闪回restore_point

 

 

 

mount状态:alter database archivelog;

(3)开启闪回

select scn,to_char(time_dp,'yyyy-mm-dd hh24:mi:ss')from sys.smon_scn_time;

(3)闪回DROP(drop table)

(4)查看闪回日志空间景况

请参考我前边的天涯论坛:http://blog.itpub.net/27067062/viewspace-2129130/

  create restore point before_201712151111 guarantee flashback
database;

SQL> alter database flashback off;
Database altered.
select scn, STORAGE_SIZE ,to_char(time,'yyyy-mm-dd hh24:mi:ss') time,NAME from v$restore_point;
select database_role,open_mode,db_unique_name,flashback_on from v$database;

SQL> set line 200;
SQL> set pagesize 2000;
SQL> select database_role,open_mode,db_unique_name,flashback_on from v$database;

DATABASE_ROLE    OPEN_MODE            DB_UNIQUE_NAME                 FLASHBACK_ON
---------------- -------------------- ------------------------------ ------------------
PHYSICAL STANDBY READ ONLY            testdbms                       NO


SQL> ALTER DATABASE CONVERT TO SNAPSHOT STANDBY;  

Database altered.

SQL> select database_role,open_mode,db_unique_name,flashback_on from v$database;

DATABASE_ROLE    OPEN_MODE            DB_UNIQUE_NAME                 FLASHBACK_ON
---------------- -------------------- ------------------------------ ------------------
SNAPSHOT STANDBY MOUNTED              testdbms                       RESTORE POINT ONLY

SQL> alter database open;

Database altered.

SQL> select open_mode from v$database;

OPEN_MODE
--------------------
READ WRITE


此时备库操作:
SQL> select * from scott.emp;

     EMPNO ENAME      JOB              MGR HIREDATE                   SAL       COMM     DEPTNO
---------- ---------- --------- ---------- ------------------- ---------- ---------- ----------
      7369 SMITH      CLERK           7902 1980-12-17 00:00:00        800                    20
      7499 ALLEN      SALESMAN        7698 1981-02-20 00:00:00       1600        300         30
      7521 WARD       SALESMAN        7698 1981-02-22 00:00:00       1250        500         30
      7566 JONES      MANAGER         7839 1981-04-02 00:00:00       2975                    20
      7654 MARTIN     SALESMAN        7698 1981-09-28 00:00:00       1250       1400         30
      7698 BLAKE      MANAGER         7839 1981-05-01 00:00:00       2850                    30
      7782 CLARK      MANAGER         7839 1981-06-09 00:00:00       2450                    10
      7788 SCOTT      ANALYST         7566 1987-04-19 00:00:00       3000                    20
      7839 KING       PRESIDENT            1981-11-17 00:00:00       5000                    10
      7844 TURNER     SALESMAN        7698 1981-09-08 00:00:00       1500          0         30
      7876 ADAMS      CLERK           7788 1987-05-23 00:00:00       1100                    20
      7900 JAMES      CLERK           7698 1981-12-03 00:00:00        950                    30
      7902 FORD       ANALYST         7566 1981-12-03 00:00:00       3000                    20
      7934 MILLER     CLERK           7782 1982-01-23 00:00:00       1300                    10

14 rows selected.

SQL> truncate table scott.emp;

Table truncated.

主库操作:
SQL> create table scott.t as select * from scott.dept;

Table created.

SQL> select * from scott.t;

    DEPTNO DNAME          LOC           ADDR
---------- -------------- ------------- ------------------------------
        10 ACCOUNTING     NEW YORK
        20 RESEARCH       DALLAS
        30 SALES          CHICAGO

备库恢复到物理standby
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount;
ORACLE instance started.

Total System Global Area 9.4067E+10 bytes
Fixed Size                  2263936 bytes
Variable Size            9663677568 bytes
Database Buffers         8.4289E+10 bytes
Redo Buffers              112766976 bytes
Database mounted.
SQL> ALTER DATABASE CONVERT TO PHYSICAL STANDBY; 

Database altered.
SQL> shutdown immediate;
ORA-01507: database not mounted


ORACLE instance shut down.
SQL> startup ;
ORACLE instance started.

Total System Global Area 9.4067E+10 bytes
Fixed Size                  2263936 bytes
Variable Size            9663677568 bytes
Database Buffers         8.4289E+10 bytes
Redo Buffers              112766976 bytes
Database mounted.
Database opened.

##此时备库的数据已经恢复到转变snapshot standby时间点
SQL> select database_role,open_mode,db_unique_name,flashback_on from v$database;

DATABASE_ROLE    OPEN_MODE            DB_UNIQUE_NAME                 FLASHBACK_ON
---------------- -------------------- ------------------------------ ------------------
PHYSICAL STANDBY READ ONLY            testdbms                       NO

SQL>  select * from scott.emp;

     EMPNO ENAME      JOB              MGR HIREDATE                   SAL       COMM     DEPTNO
---------- ---------- --------- ---------- ------------------- ---------- ---------- ----------
      7369 SMITH      CLERK           7902 1980-12-17 00:00:00        800                    20
      7499 ALLEN      SALESMAN        7698 1981-02-20 00:00:00       1600        300         30
      7521 WARD       SALESMAN        7698 1981-02-22 00:00:00       1250        500         30
      7566 JONES      MANAGER         7839 1981-04-02 00:00:00       2975                    20
      7654 MARTIN     SALESMAN        7698 1981-09-28 00:00:00       1250       1400         30
      7698 BLAKE      MANAGER         7839 1981-05-01 00:00:00       2850                    30
      7782 CLARK      MANAGER         7839 1981-06-09 00:00:00       2450                    10
      7788 SCOTT      ANALYST         7566 1987-04-19 00:00:00       3000                    20
      7839 KING       PRESIDENT            1981-11-17 00:00:00       5000                    10
      7844 TURNER     SALESMAN        7698 1981-09-08 00:00:00       1500          0         30
      7876 ADAMS      CLERK           7788 1987-05-23 00:00:00       1100                    20
      7900 JAMES      CLERK           7698 1981-12-03 00:00:00        950                    30
      7902 FORD       ANALYST         7566 1981-12-03 00:00:00       3000                    20
      7934 MILLER     CLERK           7782 1982-01-23 00:00:00       1300                    10

14 rows selected.


SQL> alter database recover managed standby database using current logfile disconnect;

Database altered.

SQL> select * from scott.t;

    DEPTNO DNAME          LOC           ADDR
---------- -------------- ------------- ------------------------------
        10 ACCOUNTING     NEW YORK
        20 RESEARCH       DALLAS
        30 SALES          CHICAGO


SQL>  select database_role,open_mode,db_unique_name,flashback_on from v$database;

DATABASE_ROLE    OPEN_MODE            DB_UNIQUE_NAME                 FLASHBACK_ON
---------------- -------------------- ------------------------------ ------------------
PHYSICAL STANDBY READ ONLY WITH APPLY testdbms                       NO
闪回级别 闪回场景 闪回技术 对象依赖   影响数据
数据库 表截断、逻辑错误、其他多表意外事件 闪回DATABASE 闪回日志、undo
DROP 删除表 闪回DROP 回收站(recyclebin)
更新、删除、插入记录 闪回TABLE 还原数据,undo
查询 当前数据和历史数据对比 闪回QUERY 还原数据,undo
版本查询 比较行版本 闪回Version Query 还原数据,undo
事务查询 比较 闪回Transaction Query 还原数据,undo
归档 DDL、DML 闪回Archive 归档日志
         

db_recovery_file_dest:指定闪回过来区的地点
db_recovery_file_dest_size:指定闪回过来区的可用空间尺寸
db_flashback_retention_target:指定数据库可以回退的年月,单位为秒钟,默许1440秒钟(1天),实际取决于闪回区大小
(2)检查是还是不是打开闪回

(5)关闭闪回

当一个表被drop掉,表会被放入recyclebin回收站,可因此回收站做表的闪回。表上的目录、约束等一律会被还原
不援救sys/system用户表空间对象,可因而alter system set
recyclebin=off;关闭回收站功效
闪回DROP示例:

SQL> select * from scott.EMP;

EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
---------- ---------- --------- ---------- ------------------- ---------- ---------- ----------
7369 SMITH CLERK 7902 1980-12-17 00:00:00 800 20
7499 ALLEN SALESMAN 7698 1981-02-20 00:00:00 1600 300 30
7521 WARD SALESMAN 7698 1981-02-22 00:00:00 1250 500 30
7566 JONES MANAGER 7839 1981-04-02 00:00:00 2975 20
7654 MARTIN SALESMAN 7698 1981-09-28 00:00:00 1250 1400 30
7698 BLAKE MANAGER 7839 1981-05-01 00:00:00 2850 30
7782 CLARK MANAGER 7839 1981-06-09 00:00:00 2450 10
7788 SCOTT ANALYST 7566 1987-04-19 00:00:00 3000 20
7839 KING PRESIDENT 1981-11-17 00:00:00 5000 10
7844 TURNER SALESMAN 7698 1981-09-08 00:00:00 1500 0 30
7876 ADAMS CLERK 7788 1987-05-23 00:00:00 1100 20
7900 JAMES CLERK 7698 1981-12-03 00:00:00 950 30
7902 FORD ANALYST 7566 1981-12-03 00:00:00 3000 20
7934 MILLER CLERK 7782 1982-01-23 00:00:00 1300 10

14 rows selected.

SQL> truncate table scott.EMP;

Table truncated.
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount;
ORACLE instance started.

Total System Global Area 9.4067E+10 bytes
Fixed Size 2263936 bytes
Variable Size 9395242112 bytes
Database Buffers 8.4557E+10 bytes
Redo Buffers 112766976 bytes
Database mounted.
SQL> flashback database to timestamp to_timestamp('2017-12-14 14:12:46','yyyy-mm-dd HH24:MI:SS');

Flashback complete.
SQL> alter database open resetlogs;

Database altered.

SQL> select * from scott.emp;

EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
---------- ---------- --------- ---------- ------------------- ---------- ---------- ----------
7369 SMITH CLERK 7902 1980-12-17 00:00:00 800 20
7499 ALLEN SALESMAN 7698 1981-02-20 00:00:00 1600 300 30
7521 WARD SALESMAN 7698 1981-02-22 00:00:00 1250 500 30
7566 JONES MANAGER 7839 1981-04-02 00:00:00 2975 20
7654 MARTIN SALESMAN 7698 1981-09-28 00:00:00 1250 1400 30
7698 BLAKE MANAGER 7839 1981-05-01 00:00:00 2850 30
7782 CLARK MANAGER 7839 1981-06-09 00:00:00 2450 10
7788 SCOTT ANALYST 7566 1987-04-19 00:00:00 3000 20
7839 KING PRESIDENT 1981-11-17 00:00:00 5000 10
7844 TURNER SALESMAN 7698 1981-09-08 00:00:00 1500 0 30
7876 ADAMS CLERK 7788 1987-05-23 00:00:00 1100 20
7900 JAMES CLERK 7698 1981-12-03 00:00:00 950 30
7902 FORD ANALYST 7566 1981-12-03 00:00:00 3000 20
7934 MILLER CLERK 7782 1982-01-23 00:00:00 1300 10

14 rows selected.
SQL> alter database flashback on;
Database altered.
SQL> select * from scott.dept;

    DEPTNO DNAME          LOC           ADDR
---------- -------------- ------------- ------------------------------
        10 ACCOUNTING     NEW YORK
        20 RESEARCH       DALLAS
        30 SALES          CHICAGO

SQL> create restore point before_201712151111 guarantee flashback database;
Restore point created.

SQL> create table scott.t as select * from scott.dept;
Table created.

SQL> truncate table scott.t;
Table truncated.
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount;
ORACLE instance started.

Total System Global Area 9.4067E+10 bytes
Fixed Size                  2263936 bytes
Variable Size            9663677568 bytes
Database Buffers         8.4289E+10 bytes
Redo Buffers              112766976 bytes
Database mounted.
SQL> flashback database to restore point before_201712151111;
Flashback complete.
SQL> alter database open resetlogs;
Database altered.

此时主库scott.t已不存在:
SQL> select * from scott.t;
select * from scott.t
                    *
ERROR at line 1:
ORA-00942: table or view does not exist
此时从库的scott.依旧存在,主备同步终止
解决方案:在主库创建快照时间点,从库自动停止应用日志,等主库闪回后,重新应用日志即可。
如果已经做了上述操作,从库可以选择重建
ALTER DATABASE REGISTER LOGFILE '/xx/xx/archive.dbf';

b.闪回版本查询

b.设置闪回区

SQL> select flashback_on from v$database;
FLASHBACK_ON
------------------
NO

(1)闪回查询
闪回查询首如若按照Undo表空间数据进行多版本查询,针对v$和x$动态品质视图无效,但对DBA_、ALL_、USER_是有效的
a.闪回查询
允许用户查询过去某个时间点的多寡,用以重构由于意外删除或改变的数据,数据不会转移。

一、Oracle闪回概述

b.快照闪回

 针对主库和备库都得以创制闪回快照点,然后还原到指定的快照点,但主库一旦恢复生机到快照点,备库的联合则必要再一次联合

SQL> select * from scott.dept;
DEPTNO DNAME LOC
---------- -------------- -------------
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON
SQL> delete from scott.dept where deptno=40;
1 row deleted.
SQL> commit;
Commit complete.
SQL> select * from scott.dept as of timestamp sysdate-10/1440;

DEPTNO DNAME LOC
---------- -------------- -------------
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON
SQL> select * from scott.dept as of timestamp to_timestamp('2017-12-14 16:20:00','yyyy-mm-dd hh24:mi:ss');

DEPTNO DNAME LOC
---------- -------------- -------------
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON

SQL> select * from scott.dept as of scn 16801523;

DEPTNO DNAME LOC
---------- -------------- -------------
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON

 

3、闪回注意事项
(1)数据库闪回必要在mounted下进展,并且open时索要接纳resetlogs
(2)闪回DROP只好用来非系统表空间和地面管理的表空间,外键约束不能復苏,对方覆盖、重命名需注意
(3)表DROP,对应的物化视图会被彻底去除,物化视图不会存放在recyclebin里
(4)闪回表,即使在做过dml,然后举行了表结构修改、truncate等DDL操作,新增/删除结构不能做闪回
(5)闪回归档,必须在assm管理tablespace和undo auto管理下展开
(6)注意闪回区管理,幸免磁盘爆满,闪回区空间不足等

SQL> select flashback_on from v$database;
FLASHBACK_ON
------------------
YES    

(5)SCN和timestamp装换关系查询

 

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