探索Oracle不完全恢复之--基于检查点恢复 第二篇
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$datafile_header;
NAME CHECKPOINT_CHANGE#
---------------------------------------------------------------
/DBBak2/oradata/WWL/system01.dbf 1510535
/DBBak2/oradata/WWL/undotbs01.dbf 1510535
/DBBak2/oradata/WWL/sysaux01.dbf 1510535
/DBBak2/oradata/WWL/users01.dbf 1510535
/DBBak2/oradata/WWL/wwl01.dbf 1510535
/DBBak2/oradata/WWL/wwl02.dbf 1510535
/DBBak2/oradata/WWL/wwl03.dbf 1510535
7 rows selected.
SQL>
2、删除测试表
SQL> drop table wwl002 purge;
Table dropped.
SQL> drop table wwl003 purge;
Table dropped.
SQL> drop table wwl004 purge;
Table dropped.
SQL> drop table wwl005 purge;
Table dropped.
SQL> conn / as sysdba
Connected.
3、对数据库执行了DML操作后，数据库的SCN号改变了。
SQL> select current_scn from v$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>
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