探索ORACLE不完全恢复之--基于检查点恢复 第二篇

探索ORACLE不完全恢复之--基于检查点恢复 第二篇

作者：吴伟龙 Name：Prodence Woo

QQ：286507175 msn:[e-mail]

基于SCN的恢复，第二篇

1、察看当前的SCN，以便于后期数据丢失用来恢复：

SQL> select current_scn from v$database;

CURRENT_SCN

-----------

1511297

SQL> select file#,checkpoint_change#from v$datafile;

FILE# CHECKPOINT_CHANGE#

---------- ------------------

1 1510535

2 1510535

3 1510535

4 1510535

5 1510535

6 1510535

7 1510535

7 rows selected.

SQL> col name format a45

SQL>set line 300

SQL> select name,checkpoint_change# fromv$datafile_header;

NAMECHECKPOINT_CHANGE#

---------------------------------------------------------------

/DBBak2/oradata/WWL/system01.dbf 1510535

/DBBak2/oradata/WWL/undotbs01.dbf 1510535

/DBBak2/oradata/WWL/sysaux01.dbf 1510535

/DBBak2/oradata/WWL/users01.dbf 1510535

/DBBak2/oradata/WWL/wwl01.dbf 1510535

/DBBak2/oradata/WWL/wwl02.dbf 1510535

/DBBak2/oradata/WWL/wwl03.dbf 1510535

7 rows selected.

SQL>

2、删除测试表

SQL> drop table wwl002 purge;

Table dropped.

SQL> drop table wwl003 purge;

Table dropped.

SQL> drop table wwl004 purge;

Table dropped.

SQL> drop table wwl005 purge;

Table dropped.

SQL> conn / as sysdba

Connected.

3、对数据库执行了DML操作后，数据库的SCN号改变了。

SQL>select current_scn from v$database;

CURRENT_SCN

-----------

1511437

4、开始执行restore，到备份时候的状态：

RMAN> restore database;

Starting restore at 13-JUL-12

using target database control file insteadof recovery catalog

allocated channel: ORA_DISK_1

channel ORA_DISK_1: sid=47 devtype=DISK

channel ORA_DISK_1: starting datafilebackupset restore

channel ORA_DISK_1: specifying datafile(s)to restore from backup set

restoring datafile 00001 to/DBBak2/oradata/WWL/system01.dbf

restoring datafile 00002 to/DBBak2/oradata/WWL/undotbs01.dbf

restoring datafile 00003 to/DBBak2/oradata/WWL/sysaux01.dbf

restoring datafile 00004 to/DBBak2/oradata/WWL/users01.dbf

restoring datafile 00005 to/DBBak2/oradata/WWL/wwl01.dbf

restoring datafile 00006 to/DBBak2/oradata/WWL/wwl02.dbf

restoring datafile 00007 to/DBBak2/oradata/WWL/wwl03.dbf

channel ORA_DISK_1: reading from backuppiece /DBSoft/product/10.2.0/db_1/dbs/01nft4mu_1_1

channel ORA_DISK_1: restored backup piece 1

piecehandle=/DBSoft/product/10.2.0/db_1/dbs/01nft4mu_1_1 tag=TAG20120712T095437

channel ORA_DISK_1: restore complete,elapsed time: 00:01:06

Finished restore at 13-JUL-12

5、开始执行恢复，到我们删除表之前的状态：

SQL> recover database until change1511297;

ORA-00279: change 1436429 generated at07/12/2012 09:54:38 needed for thread 1

ORA-00289: suggestion :/DBSoft/product/10.2.0/db_1/dbs/arch1_3_788372282.dbf

ORA-00280: change 1436429 for thread 1 isin sequence #3

Specify log: {<RET>=suggested |filename | AUTO | CANCEL}

auto

ORA-00279: change 1440657 generated at07/12/2012 14:00:52 needed for thread 1

ORA-00289: suggestion :/DBSoft/product/10.2.0/db_1/dbs/arch1_1_788450452.dbf

ORA-00280: change 1440657 for thread 1 isin sequence #1

ORA-00279: change 1440855 generated at 07/12/201215:08:58 needed for thread 1

ORA-00289: suggestion :/DBSoft/product/10.2.0/db_1/dbs/arch1_1_788454538.dbf

ORA-00280: change 1440855 for thread 1 isin sequence #1

ORA-00279: change 1441316 generated at07/12/2012 15:19:50 needed for thread 1

ORA-00289: suggestion :/DBSoft/product/10.2.0/db_1/dbs/arch1_1_788455190.dbf

ORA-00280: change 1441316 for thread 1 isin sequence #1

ORA-00279: change 1442275 generated at07/12/2012 15:52:01 needed for thread 1

ORA-00289: suggestion : /DBSoft/product/10.2.0/db_1/dbs/arch1_1_788457121.dbf

ORA-00280: change 1442275 for thread 1 isin sequence #1

ORA-00279: change 1442953 generated at07/12/2012 16:25:06 needed for thread 1

ORA-00289: suggestion :/DBSoft/product/10.2.0/db_1/dbs/arch1_1_788459106.dbf

ORA-00280: change 1442953 for thread 1 isin sequence #1

ORA-00279: change 1462958 generated at07/12/2012 16:28:16 needed for thread 1

ORA-00289: suggestion :/DBSoft/product/10.2.0/db_1/dbs/arch1_2_788459106.dbf

ORA-00280: change 1462958 for thread 1 is insequence #2

ORA-00278: log file'/DBSoft/product/10.2.0/db_1/dbs/arch1_1_788459106.dbf' no

longer needed for this recovery

ORA-00279: change 1462963 generated at07/12/2012 17:17:59 needed for thread 1

ORA-00289: suggestion :/DBSoft/product/10.2.0/db_1/dbs/arch1_1_788462279.dbf

ORA-00280: change 1462963 for thread 1 isin sequence #1

ORA-00279: change 1483784 generated at07/12/2012 17:54:25 needed for thread 1

ORA-00289: suggestion :/DBSoft/product/10.2.0/db_1/dbs/arch1_2_788462279.dbf

ORA-00280: change 1483784 for thread 1 isin sequence #2

ORA-00278: log file'/DBSoft/product/10.2.0/db_1/dbs/arch1_1_788462279.dbf' no

longer needed for this recovery

ORA-00279: change 1486119 generated at07/12/2012 20:35:27 needed for thread 1

ORA-00289: suggestion :/DBSoft/product/10.2.0/db_1/dbs/arch1_1_788474127.dbf

ORA-00280: change 1486119 for thread 1 isin sequence #1

ORA-00279: change 1487388 generated at07/12/2012 21:31:17 needed for thread 1

ORA-00289: suggestion :/DBSoft/product/10.2.0/db_1/dbs/arch1_1_788477477.dbf

ORA-00280: change 1487388 for thread 1 isin sequence #1

Log applied.

Media recovery complete.

SQL>

6、执行完恢复之后，SCN被清空

SQL> select current_scn from v$database;

CURRENT_SCN

-----------

0

7、这个时候我们需要对redo也进行清空

SQL> alter database open restlogs;

8、由此可以见得，数据已经恢复回来了：

SQL> select * from tab;

TNAME TABTYPE CLUSTERID

------------------------------ -----------------

WWL001 TABLE

WWL002 TABLE

WWL003 TABLE

WWL004 TABLE

WWL005 TABLE

SQL> select * from wwl005;

ID NAME

---------- ------------

1 wwl

2 prodence

3 woo

4 xgx

5 cms

SQL>