今天做了一个关于破坏online日志的恢复測试，主要三个场景：
測试1：正常关闭数据库后删除非当前日志
測试2：正常关库后。删除在线日志文件
測试3：非正常关闭数据库。并删除当前在线日志文件
我的測试环境是Oracle 10.2.0.1 32bit的数据库，OS版本号为red hat 5.3，以下看详细測试经过：
測试1：正常关闭数据库后删除非当前日志
[oracle@ora10g ~]$ sqlplus / as sysdba
SQL*Plus: Release 10.2.0.1.0 - Production on 星期三 6月 24 10:34:53 2015
Copyright (c) 1982, 2005, Oracle. All rights reserved.
Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
SYS@ora10g> select group#,thread#,status,archived from v$log;
GROUP# THREAD# STATUS ARC
---------- ---------- ---------------- ---
1 1 CURRENT
NO
2 1 INACTIVE
YES
3 1 ACTIVE
YES
SYS@ora10g> set line 130 pages 130
SYS@ora10g> col member for a50
SYS@ora10g> select * from v$logfile;
GROUP# STATUS TYPE MEMBER IS_
---------- ------- ------- -------------------------------------------------- ---
3 ONLINE /u01/app/oracle/oradata/ora10g/redo03.log NO
2 ONLINE /u01/app/oracle/oradata/ora10g/redo02.log NO
1 ONLINE /u01/app/oracle/oradata/ora10g/redo01.log NO
SYS@ora10g> conn zlm/zlm
Connected.
ZLM@ora10g> create table t1 as select * from dba_objects where 1=2;
Table created.
ZLM@ora10g> insert into t1 select * from dba_objects where rownum<11;
10 rows created.
ZLM@ora10g> select count(*) from t1;
COUNT(*)
----------
10
ZLM@ora10g> commit; （此处不commit也可。由于对在线日志归档的时候会进行commit操作）
Commit complete.
ZLM@ora10g> alter system archive log current;
System altered.
ZLM@ora10g> select group#,thread#,status,archived from v$log;
GROUP# THREAD# STATUS ARC
---------- ---------- ---------------- ---
1 1 ACTIVE
YES
2 1 CURRENT
NO
3 1 INACTIVE
YES
--删除非当前的在线日志文件（ACTIVE的和INACTIVE的）
[oracle@ora10g backupsets]$ cd /u01/app/oracle/oradata/ora10g/
[oracle@ora10g ora10g]$ pwd
/u01/app/oracle/oradata/ora10g
[oracle@ora10g ora10g]$ ls -l
total 1461348
-rw-r----- 1 oracle oinstall 7520256 Jun 24 10:40 control01.ctl
-rw-r----- 1 oracle oinstall 7520256 Jun 24 10:40 control02.ctl
-rw-r----- 1 oracle oinstall 7520256 Jun 24 10:40 control03.ctl
-rw-r----- 1 oracle oinstall 104865792 Jun 24 10:38 example01.dbf
-rw-r----- 1 oracle oinstall 172032 Nov 29 2014 indx01.dbf
-rw-r----- 1 oracle oinstall 52429312 Jun 24 10:39 redo01.log
-rw-r----- 1 oracle oinstall 52429312 Jun 24 10:39 redo02.log
-rw-r----- 1 oracle oinstall 52429312 Jun 24 10:34 redo03.log
-rw-r----- 1 oracle oinstall 283123712 Jun 24 10:38 sysaux01.dbf
-rw-r----- 1 oracle oinstall 587210752 Jun 24 10:38 system01.dbf
-rw-r----- 1 oracle oinstall 52436992 Jun 23 16:17 temp01.dbf
-rw-r----- 1 oracle oinstall 173023232 Jun 24 10:38 undotbs01.dbf
-rw-r----- 1 oracle oinstall 41951232 Jun 24 10:38 users01.dbf
-rw-r----- 1 oracle oinstall 100671488 Jun 24 10:38 zlm01.dbf
[oracle@ora10g ora10g]$ rm -f redo01.log
[oracle@ora10g ora10g]$ rm -f redo03.log
[oracle@ora10g ora10g]$ ls -l redo*
-rw-r----- 1 oracle oinstall 52429312 Jun 24 10:44 redo02.log
[oracle@ora10g ora10g]$
測试1：正常关闭数据库后删除非当前日志
--正常关闭数据库并重新启动
ZLM@ora10g> shutdown immediate
ORA-01031: insufficient privileges
ZLM@ora10g> conn / as sysdba
Connected.
SYS@ora10g> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SYS@ora10g> startup
ORACLE instance started.
Total System Global Area 524288000 bytes
Fixed Size
1220384 bytes
Variable Size
318767328 bytes
Database Buffers 201326592 bytes
Redo Buffers
2973696 bytes
Database mounted.
ORA-00313: open failed for members of log group 1 of thread 1
ORA-00312: online log 1 thread 1: '/u01/app/oracle/oradata/ora10g/redo01.log'
提示无法打开日志组1的日志文件，由于之前在OS层面已经将其删除了
--观察alert日志
[oracle@ora10g ora10g]$ cd /u01/app/oracle/admin/ora10g/bdump/
[oracle@ora10g bdump]$ tail -50f alert_ora10g.log
MMON started with pid=11, OS id=2970
Wed Jun 24 10:45:54 2015
starting up 1 dispatcher(s) for network address '(ADDRESS=(PARTIAL=YES)(PROTOCOL=TCP))'...
starting up 1 shared server(s) ...
CJQ0 started with pid=10, OS id=2968
MMNL started with pid=12, OS id=2972
Wed Jun 24 10:45:55 2015
ALTER DATABASE MOUNT
Wed Jun 24 10:45:58 2015
Setting recovery target incarnation to 8
Wed Jun 24 10:45:58 2015
Successful mount of redo thread 1, with mount id 4202063779
Wed Jun 24 10:45:58 2015
Database mounted in Exclusive Mode
Completed: ALTER DATABASE MOUNT
Wed Jun 24 10:45:59 2015
ALTER DATABASE OPEN
Wed Jun 24 10:45:59 2015
LGWR: STARTING ARCH PROCESSES
ARC0 started with pid=16, OS id=2980
Wed Jun 24 10:45:59 2015
ARC0: Archival started
ARC1: Archival started
LGWR: STARTING ARCH PROCESSES COMPLETE
Wed Jun 24 10:45:59 2015
Errors in file /u01/app/oracle/admin/ora10g/bdump/ora10g_lgwr_2960.trc:
ORA-00313: Message 313 not found; No message file for product=RDBMS, facility=ORA; arguments: [1] [1]
ORA-00312: Message 312 not found; No message file for product=RDBMS, facility=ORA; arguments: [1] [1] [/u01/app/oracle/oradata/ora10g/redo01.log]
ORA-27037: Message 27037 not found; No message file for product=RDBMS, facility=ORA
Linux Error: 2: No such file or directory
Additional information: 3
Wed Jun 24 10:45:59 2015
Errors in file /u01/app/oracle/admin/ora10g/bdump/ora10g_lgwr_2960.trc:
ORA-00313: Message 313 not found; No message file for product=RDBMS, facility=ORA; arguments: [1] [1]
ORA-00312: Message 312 not found; No message file for product=RDBMS, facility=ORA; arguments: [1] [1] [/u01/app/oracle/oradata/ora10g/redo01.log]
ORA-27037: Message 27037 not found; No message file for product=RDBMS, facility=ORA
Linux Error: 2: No such file or directory
Additional information: 3
Wed Jun 24 10:45:59 2015
ARC0: STARTING ARCH PROCESSES
ARC2: Archival started
ARC0: STARTING ARCH PROCESSES COMPLETE
ARC0: Becoming the 'no FAL' ARCH
ARC0: Becoming the 'no SRL' ARCH
ARC1 started with pid=17, OS id=2982
Wed Jun 24 10:46:00 2015
ARC1: Becoming the heartbeat ARCH
ARC2 started with pid=18, OS id=2984
Wed Jun 24 10:46:00 2015
ORA-313 signalled during: ALTER DATABASE OPEN...
发现确实是读取redo01.log文件错误，无法OPEN数据库，仅仅停留在MOUNT状态
--清空刚才被删除的2个在线日志文件（相当于重建）
SYS@ora10g> select open_mode from v$database;
OPEN_MODE
----------
MOUNTED
SYS@ora10g> alter database clear logfile group 1;
Database altered.
SYS@ora10g> alter database open;
alter database open
*
ERROR at line 1:
ORA-00313: open failed for members of log group 3 of thread 1
ORA-00312: online log 3 thread 1: '/u01/app/oracle/oradata/ora10g/redo03.log'
SYS@ora10g> alter database clear logfile group 3;
Database altered.
SYS@ora10g> alter database open;
Database altered.
SYS@ora10g> conn zlm/zlm
Connected.
ZLM@ora10g> select count(*) from t1;
COUNT(*)
----------
10
ZLM@ora10g>
虽然删除了2个非在线日志文件，那么就能够非常方便的将数据库打开。仅仅要重建被删除的日志文件即可（通过CLEAR操作），且数据并不会丢失（由于是shutdown immediate方式关闭库的）
--继续查看alert日志内容
Wed Jun 24 10:48:55 2015
alter database clear logfile group 1
Wed Jun 24 10:48:56 2015
Clearing online log 1 of thread 1 sequence number 20
Wed Jun 24 10:48:56 2015
Errors in file /u01/app/oracle/admin/ora10g/udump/ora10g_ora_2978.trc:
ORA-00313: open failed for members of log group 1 of thread 1
ORA-00312: online log 1 thread 1: '/u01/app/oracle/oradata/ora10g/redo01.log'
ORA-27037: unable to obtain file status
Linux Error: 2: No such file or directory
Additional information: 3
Completed: alter database clear logfile group 1
Wed Jun 24 10:49:03 2015
alter database open
Wed Jun 24 10:49:03 2015
Errors in file /u01/app/oracle/admin/ora10g/bdump/ora10g_lgwr_2960.trc:
ORA-00313: Message 313 not found; No message file for product=RDBMS, facility=ORA; arguments: [3] [1]
ORA-00312: Message 312 not found; No message file for product=RDBMS, facility=ORA; arguments: [3] [1] [/u01/app/oracle/oradata/ora10g/redo03.log]
ORA-27037: Message 27037 not found; No message file for product=RDBMS, facility=ORA
Linux Error: 2: No such file or directory
Additional information: 3
Wed Jun 24 10:49:03 2015
Errors in file /u01/app/oracle/admin/ora10g/bdump/ora10g_lgwr_2960.trc:
ORA-00313: Message 313 not found; No message file for product=RDBMS, facility=ORA; arguments: [3] [1]
ORA-00312: Message 312 not found; No message file for product=RDBMS, facility=ORA; arguments: [3] [1] [/u01/app/oracle/oradata/ora10g/redo03.log]
ORA-27037: Message 27037 not found; No message file for product=RDBMS, facility=ORA
Linux Error: 2: No such file or directory
Additional information: 3
ORA-313 signalled during: alter database open...
Wed Jun 24 10:49:14 2015
alter database clear logfile group 3
Wed Jun 24 10:49:14 2015
Clearing online log 3 of thread 1 sequence number 19
Wed Jun 24 10:49:14 2015
Errors in file /u01/app/oracle/admin/ora10g/udump/ora10g_ora_2978.trc:
ORA-00313: open failed for members of log group 3 of thread 1
ORA-00312: online log 3 thread 1: '/u01/app/oracle/oradata/ora10g/redo03.log'
ORA-27037: unable to obtain file status
Linux Error: 2: No such file or directory
Additional information: 3
Completed: alter database clear logfile group 3
Wed Jun 24 10:49:22 2015
alter database open
Wed Jun 24 10:49:22 2015
Thread 1 advanced to log sequence 22
Thread 1 opened at log sequence 22
Current log# 1 seq# 22 mem# 0: /u01/app/oracle/oradata/ora10g/redo01.log
Successful open of redo thread 1
Wed Jun 24 10:49:23 2015
db_recovery_file_dest_size of 2048 MB is 0.04% used. This is a
user-specified limit on the amount of space that will be used by this
database for recovery-related files, and does not reflect the amount of
space available in the underlying filesystem or ASM diskgroup.
Wed Jun 24 10:49:23 2015
MTTR advisory is disabled because FAST_START_MTTR_TARGET is not set
Wed Jun 24 10:49:23 2015
SMON: enabling cache recovery
Wed Jun 24 10:49:23 2015
Successfully onlined Undo Tablespace 1.
Wed Jun 24 10:49:23 2015
SMON: enabling tx recovery
Wed Jun 24 10:49:24 2015
Database Characterset is ZHS16GBK
replication_dependency_tracking turned off (no async multimaster replication found)
Starting background process QMNC
QMNC started with pid=19, OS id=2993
Wed Jun 24 10:49:31 2015
Completed: alter database open
在CLEAR操作后，OS会创建对应的日志组成员文件，然后数据库就能够正常读取了，此时并不须要通过restore和recover对数据库进行恢复和还原就可以
測试2：正常关库后。删除在线日志文件
ZLM@ora10g> select group#,thread#,status,archived from v$log;
GROUP# THREAD# STATUS ARC
---------- ---------- ---------------- ---
1 1 CURRENT
NO
2 1 INACTIVE
YES
3 1 UNUSED
YES
ZLM@ora10g> insert into t1 select * from dba_objects where rownum<11;
10 rows created.
ZLM@ora10g> select count(*) from t1;
COUNT(*)
----------
20
ZLM@ora10g> alter system archive log current;
System altered.
ZLM@ora10g> select group#,thread#,status,archived from v$log;
GROUP# THREAD# STATUS ARC
---------- ---------- ---------------- ---
1 1 ACTIVE
YES
2 1 INACTIVE
YES
3 1 CURRENT
NO
--正常关闭数据库
ZLM@ora10g> shutdown immediate
ORA-01031: insufficient privileges
ZLM@ora10g> conn / as sysdba
Connected.
SYS@ora10g> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SYS@ora10g>
--OS上删除current的在线日志文件redo03.log
[oracle@ora10g ~]$ cd /u01/app/oracle/oradata/ora10g
[oracle@ora10g ora10g]$ ls -l
total 1461348
-rw-r----- 1 oracle oinstall 7520256 Jun 24 11:03 control01.ctl
-rw-r----- 1 oracle oinstall 7520256 Jun 24 11:03 control02.ctl
-rw-r----- 1 oracle oinstall 7520256 Jun 24 11:03 control03.ctl
-rw-r----- 1 oracle oinstall 104865792 Jun 24 11:03 example01.dbf
-rw-r----- 1 oracle oinstall 172032 Nov 29 2014 indx01.dbf
-rw-r----- 1 oracle oinstall 52429312 Jun 24 11:02 redo01.log
-rw-r----- 1 oracle oinstall 52429312 Jun 24 10:49 redo02.log
-rw-r----- 1 oracle oinstall 52429312 Jun 24 11:03 redo03.log
-rw-r----- 1 oracle oinstall 283123712 Jun 24 11:03 sysaux01.dbf
-rw-r----- 1 oracle oinstall 587210752 Jun 24 11:03 system01.dbf
-rw-r----- 1 oracle oinstall 52436992 Jun 23 16:17 temp01.dbf
-rw-r----- 1 oracle oinstall 173023232 Jun 24 11:03 undotbs01.dbf
-rw-r----- 1 oracle oinstall 41951232 Jun 24 11:03 users01.dbf
-rw-r----- 1 oracle oinstall 100671488 Jun 24 11:03 zlm01.dbf
[oracle@ora10g ora10g]$ rm -f redo03.log
[oracle@ora10g ora10g]$ ls -l redo*
-rw-r----- 1 oracle oinstall 52429312 Jun 24 11:02 redo01.log
-rw-r----- 1 oracle oinstall 52429312 Jun 24 10:49 redo02.log
[oracle@ora10g ora10g]$
--启动数据库
SYS@ora10g> startup
ORACLE instance started.
Total System Global Area 524288000 bytes
Fixed Size
1220384 bytes
Variable Size
322961632 bytes
Database Buffers 197132288 bytes
Redo Buffers
2973696 bytes
Database mounted.
ORA-00313: open failed for members of log group 3 of thread 1
ORA-00312: online log 3 thread 1: '/u01/app/oracle/oradata/ora10g/redo03.log'
由于启动数据库会检查全部的文件。读取到在线日志文件redo03.log时，就报错了，由于已经被删除
--还原数据库
SYS@ora10g> recover database until cancel;
Media recovery complete.
SYS@ora10g> alter database open;
alter database open
*
ERROR at line 1:
ORA-01589: must use RESETLOGS or NORESETLOGS option for database open
因为之前是正常关闭数据库。在线日志的内容已经写到归档日志文件，利用归档日志进行还原，而还原后的数据库，必须用resetlogs方式来OPEN数据库
SYS@ora10g> alter database open resetlogs;
Database altered.
SYS@ora10g> conn zlm/zlm
Connected.
ZLM@ora10g> select count(*) from t1;
COUNT(*)
----------
20
ZLM@ora10g>
仅仅要是正常关闭数据库的，而且开启了归档。那么即便是删除了current的在线日志，也是能够将数据库又一次打开的，而且不会丢失数据（由归档来保证）
測试3：非正常关闭数据库。并删除当前在线日志文件
--加入測试数据后。abort方式关闭数据库
ZLM@ora10g> select group#,thread#,status,archived from v$log;
GROUP# THREAD# STATUS ARC
---------- ---------- ---------------- ---
1 1 CURRENT
NO
2 1 UNUSED
YES
3 1 INACTIVE
YES
ZLM@ora10g> insert into t1 select * from dba_objects where rownum<11;
10 rows created.
ZLM@ora10g> select count(*) from t1;
COUNT(*)
----------
30
ZLM@ora10g> alter system archive log current;
System altered.
ZLM@ora10g> select group#,thread#,status,archived from v$log;
GROUP# THREAD# STATUS ARC
---------- ---------- ---------------- ---
1 1 ACTIVE
YES
2 1 CURRENT
NO
3 1 INACTIVE
YES
ZLM@ora10g> shutdown abort
ORA-01031: insufficient privileges
ZLM@ora10g> conn / as sysdba
Connected.
SYS@ora10g> shutdown abort
ORACLE instance shut down.
SYS@ora10g>
--OS上将current在线日志文件redo02.log删除
[oracle@ora10g ora10g]$ rm -f redo02.log
[oracle@ora10g ora10g]$ ls -l redo*
-rw-r----- 1 oracle oinstall 52429312 Jun 24 11:16 redo01.log
-rw-r----- 1 oracle oinstall 52429312 Jun 24 11:08 redo03.log
--再次启动数据库
SYS@ora10g> startup
ORACLE instance started.
Total System Global Area 524288000 bytes
Fixed Size
1220384 bytes
Variable Size
327155936 bytes
Database Buffers 192937984 bytes
Redo Buffers
2973696 bytes
Database mounted.
ORA-00313: open failed for members of log group 2 of thread 1
ORA-00312: online log 2 thread 1: '/u01/app/oracle/oradata/ora10g/redo02.log'
ORA-27037: unable to obtain file status
Linux Error: 2: No such file or directory
Additional information: 3
SYS@ora10g> alter database clear logfile group 2;
alter database clear logfile group 2
*
ERROR at line 1:
ORA-01624: log 2 needed for crash recovery of instance ora10g (thread 1)
ORA-00312: online log 2 thread 1: '/u01/app/oracle/oradata/ora10g/redo02.log'
SYS@ora10g> recover database until cancel;
ORA-00279: change 1497127 generated at 06/24/2015 11:08:48 needed for thread 1
ORA-00289: suggestion : /u01/app/oracle/flash_recovery_area/ORA10G/archivelog/2015_06_24/o1_mf_1_2_%u_.arc
ORA-00280: change 1497127 for thread 1 is in sequence #2
Specify log: {<RET>=suggested | filename | AUTO | CANCEL}
cancel
ORA-01547: warning: RECOVER succeeded but OPEN RESETLOGS would get error below
ORA-01194: file 1 needs more recovery to be consistent
ORA-01110: data file 1: '/u01/app/oracle/oradata/ora10g/system01.dbf'
ORA-01112: media recovery not started
SYS@ora10g>
之前使用的方法，在此处都不成立。原因是数据库强制要求current的在线日志文件须要crash recover，又一次创建自然是不行的，因为是非正常关闭数据库。也没有写入归档文件。当然也无法进行还原，那么此时仅仅有通过别的方法来将数据库OPEN了，当然丢失数据已经是不可避免的了，也就是刚才current在线日志文件里未归档的那部分，即t1表中最后插入的10条记录，权衡利弊，即便是丢数据。也要先将数据库拉起来，那么能够通过设置隐含參数"_allow_resetlogs_corruption=true"来实现
SYS@ora10g> create pfile from spfile;
File created.
SYS@ora10g> show parameter spfile
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
spfile string /u01/app/oracle/product/10.2.0
/db_1/dbs/spfileora10g.ora
SYS@ora10g> host
[oracle@ora10g ~]$ cd /u01/app/oracle/product/10.2.0/db_1/dbs/
[oracle@ora10g dbs]$ ls -l
total 7412
-rwxr-xr-x 1 oracle oinstall 5494 Aug 26 2014 alert_ora10g.log
-rwxr-xr-x 1 oracle oinstall 1544 Aug 25 2014 hc_ora10g.dat
-rwxr-xr-x 1 oracle oinstall 12920 May 3 2001 initdw.ora
-rwxr-xr-x 1 oracle oinstall 8385 Sep 11 1998 init.ora
-rw-r--r-- 1 oracle oinstall 1343 Jun 24 11:24 initora10g.ora
-rwxr-xr-x 1 oracle oinstall 24 Aug 25 2014 lkORA10G
-rw-r----- 1 oracle oinstall 1536 Nov 26 2014 orapwora10g
-rwxr-xr-x 1 oracle oinstall 7520256 Jun 24 11:09 snapcf_ora10g.f
-rw-r----- 1 oracle oinstall 3584 Jun 24 11:19 spfileora10g.ora
[oracle@ora10g dbs]$ echo "_allow_resetlogs_corruption=true" >> initora10g.ora
[oracle@ora10g dbs]$ cat initora10g.ora
ora10g.__db_cache_size=192937984
ora10g.__java_pool_size=4194304
ora10g.__large_pool_size=4194304
ora10g.__shared_pool_size=155189248
ora10g.__streams_pool_size=8388608
*._disable_image_check=TRUE
*.audit_file_dest='/u01/app/oracle/admin/ora10g/adump'
*.background_dump_dest='/u01/app/oracle/admin/ora10g/bdump'
*.compatible='10.2.0.1.0'
*.control_files='/u01/app/oracle/oradata/ora10g/control01.ctl','/u01/app/oracle/oradata/ora10g/control02.ctl','/u01/app/oracle/oradata/ora10g/control03.ctl'#Restore Controlfile
*.core_dump_dest='/u01/app/oracle/admin/ora10g/cdump'
*.db_block_size=8192
*.db_cache_size=0
*.db_domain=''
*.db_file_multiblock_read_count=16
*.db_name='ora10g'
*.db_recovery_file_dest='/u01/app/oracle/flash_recovery_area'
*.db_recovery_file_dest_size=2147483648
*.dispatchers='(PROTOCOL=TCP) (SERVICE=ora10gXDB)'
*.java_pool_size=4194304
*.job_queue_processes=10
*.large_pool_size=4194304
*.log_archive_format='%t_%s_%r.dbf'
*.nls_language='SIMPLIFIED CHINESE'
*.nls_territory='CHINA'
*.open_cursors=300
*.pga_aggregate_target=94371840
*.processes=150
*.remote_login_passwordfile='EXCLUSIVE'
*.sga_max_size=524288000
*.sga_target=369098752
*.shared_pool_size=0
*.statistics_level='TYPICAL'
*.streams_pool_size=8388608
*.undo_management='AUTO'
*.undo_tablespace='UNDOTBS1'
*.user_dump_dest='/u01/app/oracle/admin/ora10g/udump'
_allow_resetlogs_corruption
[oracle@ora10g dbs]$ vi initora10g.ora
[oracle@ora10g dbs]$ cat initora10g.ora
ora10g.__db_cache_size=192937984
ora10g.__java_pool_size=4194304
ora10g.__large_pool_size=4194304
ora10g.__shared_pool_size=155189248
ora10g.__streams_pool_size=8388608
*._disable_image_check=TRUE
*.audit_file_dest='/u01/app/oracle/admin/ora10g/adump'
*.background_dump_dest='/u01/app/oracle/admin/ora10g/bdump'
*.compatible='10.2.0.1.0'
*.control_files='/u01/app/oracle/oradata/ora10g/control01.ctl','/u01/app/oracle/oradata/ora10g/control02.ctl','/u01/app/oracle/oradata/ora10g/control03.ctl'#Restore Controlfile
*.core_dump_dest='/u01/app/oracle/admin/ora10g/cdump'
*.db_block_size=8192
*.db_cache_size=0
*.db_domain=''
*.db_file_multiblock_read_count=16
*.db_name='ora10g'
*.db_recovery_file_dest='/u01/app/oracle/flash_recovery_area'
*.db_recovery_file_dest_size=2147483648
*.dispatchers='(PROTOCOL=TCP) (SERVICE=ora10gXDB)'
*.java_pool_size=4194304
*.job_queue_processes=10
*.large_pool_size=4194304
*.log_archive_format='%t_%s_%r.dbf'
*.nls_language='SIMPLIFIED CHINESE'
*.nls_territory='CHINA'
*.open_cursors=300
*.pga_aggregate_target=94371840
*.processes=150
*.remote_login_passwordfile='EXCLUSIVE'
*.sga_max_size=524288000
*.sga_target=369098752
*.shared_pool_size=0
*.statistics_level='TYPICAL'
*.streams_pool_size=8388608
*.undo_management='AUTO'
*.undo_tablespace='UNDOTBS1'
*.user_dump_dest='/u01/app/oracle/admin/ora10g/udump'
_allow_resetlogs_corruption=true
SYS@ora10g> startup
ORA-01081: cannot start already-running ORACLE - shut it down first
SYS@ora10g> shutdown abort
ORACLE instance shut down.
SYS@ora10g> startup pfile=/u01/app/oracle/product/10.2.0/db_1/dbs/initora10g.ora
ORACLE instance started.
Total System Global Area 524288000 bytes
Fixed Size
1220384 bytes
Variable Size
327155936 bytes
Database Buffers 192937984 bytes
Redo Buffers
2973696 bytes
Database mounted.
ORA-01589: must use RESETLOGS or NORESETLOGS option for database open
SYS@ora10g> alter database open resetlogs;
alter database open resetlogs
*
ERROR at line 1:
ORA-01092: ORACLE instance terminated. Disconnection forced
注意：此处的操作。在11g中，是能够直接用resetlogs方式OPEN数据库的。可是10g还须要做很多其它的处理
SYS@ora10g> shutdown abort
ORACLE instance shut down.
SYS@ora10g> startup
ORACLE instance started.
Total System Global Area 524288000 bytes
Fixed Size
1220384 bytes
Variable Size
327155936 bytes
Database Buffers 192937984 bytes
Redo Buffers
2973696 bytes
Database mounted.
ORA-03113: end-of-file on communication channel
SYS@ora10g> shutdown abort
ORACLE instance shut down.
SYS@ora10g> startup mount pfile=/u01/app/oracle/product/10.2.0/db_1/dbs/initora10g.ora
ORACLE instance started.
Total System Global Area 524288000 bytes
Fixed Size
1220384 bytes
Variable Size
327155936 bytes
Database Buffers 192937984 bytes
Redo Buffers
2973696 bytes
Database mounted.
SYS@ora10g> create spfile from pfile;
File created.
SYS@ora10g> shutdown abort
ORACLE instance shut down.
SYS@ora10g> startup mount
ORACLE instance started.
Total System Global Area 524288000 bytes
Fixed Size
1220384 bytes
Variable Size
327155936 bytes
Database Buffers 192937984 bytes
Redo Buffers
2973696 bytes
Database mounted.
SYS@ora10g> show parameter spfile
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
spfile string /u01/app/oracle/product/10.2.0
/db_1/dbs/spfileora10g.ora
SYS@ora10g> alter database open;
alter database open
*
ERROR at line 1:
ORA-00603: ORACLE server session terminated by fatal error
--查看此时alert日志，报ora-600错误 [4194]
Wed Jun 24 11:55:14 2015
Errors in file /u01/app/oracle/admin/ora10g/udump/ora10g_ora_4112.trc:
ORA-00600: internal error code, arguments: [4194], [36], [33], [], [], [], [], []
ORA-00600: internal error code, arguments: [4194], [36], [33], [], [], [], [], []
Wed Jun 24 11:55:42 2015
Errors in file /u01/app/oracle/admin/ora10g/bdump/ora10g_smon_4098.trc:
ORA-00600: Message 600 not found; No message file for product=RDBMS, facility=ORA; arguments: [4194] [36] [33]
Wed Jun 24 11:55:44 2015
Fatal internal error happened while SMON was doing active transaction recovery.
Wed Jun 24 11:55:44 2015
Errors in file /u01/app/oracle/admin/ora10g/bdump/ora10g_smon_4098.trc:
ORA-00600: Message 600 not found; No message file for product=RDBMS, facility=ORA; arguments: [4194] [36] [33]
SMON: terminating instance due to error 474
Instance terminated by SMON, pid = 4098
通常ORA-00600 [4194]的错误会跟回滚段错误相关，继续查看trace文件/u01/app/oracle/admin/ora10g/bdump/orcl_smon_4098.trc，看到下述相关信息：
13121D07:00000B4B 15 159 10444 14 Acq rbs SYSTEM
13122395:00000B4C 15 159 10444 13 UNDO SEG (BEFORE RECOVERY): usn = 0
131224AB:00000B4D 15 159 10444 13 UNDO SEG (BEFORE RECOVERY): usn = 0
13124171:00000B4E 15 159 10444 14 Rec rbs _SYSSMU1$
1312455C:00000B4F 15 159 10444 13 UNDO SEG (BEFORE RECOVERY): usn = 1
13131FE0:00000B50 15 159 10005 4 KSL POST SENT postee=6 loc='ksasnd' id1=0 id2=0 name= type=0
13133EDD:00000B59 15 159 10444 14 Rec rbs _SYSSMU2$
13134C80:00000B5A 15 159 10444 13 UNDO SEG (BEFORE RECOVERY): usn = 2
13135B8B:00000B5B 15 159 10005 4 KSL POST SENT postee=6 loc='ksasnd' id1=0 id2=0 name= type=0
13136B7A:00000B5F 15 159 10444 14 Rec rbs _SYSSMU3$
13136EA7:00000B60 15 159 10444 13 UNDO SEG (BEFORE RECOVERY): usn = 3
13137438:00000B61 15 159 10005 4 KSL POST SENT postee=6 loc='ksasnd' id1=0 id2=0 name= type=0
13138A0D:00000B67 15 159 10444 14 Rec rbs _SYSSMU4$
13138FA8:00000B68 15 159 10444 13 UNDO SEG (BEFORE RECOVERY): usn = 4
13139598:00000B69 15 159 10005 4 KSL POST SENT postee=6 loc='ksasnd' id1=0 id2=0 name= type=0
13139B3C:00000B6A 15 159 10444 14 Rec rbs _SYSSMU5$
13139E47:00000B6B 15 159 10444 13 UNDO SEG (BEFORE RECOVERY): usn = 5
1313B8FB:00000B71 15 159 10444 14 Rec rbs _SYSSMU6$
1313BE12:00000B72 15 159 10444 13 UNDO SEG (BEFORE RECOVERY): usn = 6
1313C276:00000B73 15 159 10005 4 KSL POST SENT postee=6 loc='ksasnd' id1=0 id2=0 name= type=0
1313C536:00000B74 15 159 10444 14 Rec rbs _SYSSMU7$
1313CAEA:00000B75 15 159 10444 13 UNDO SEG (BEFORE RECOVERY): usn = 7
1313D804:00000B76 15 159 10444 14 Rec rbs _SYSSMU8$
1313E48F:00000B7C 15 159 10444 13 UNDO SEG (BEFORE RECOVERY): usn = 8
1313E9E3:00000B7D 15 159 10005 4 KSL POST SENT postee=6 loc='ksasnd' id1=0 id2=0 name= type=0
1313ECF3:00000B7E 15 159 10444 14 Rec rbs _SYSSMU9$
1313F050:00000B7F 15 159 10444 13 UNDO SEG (BEFORE RECOVERY): usn = 9
1313F7F2:00000B80 15 159 10444 14 Rec rbs _SYSSMU10$
1313FEED:00000B81 15 159 10444 13 UNDO SEG (BEFORE RECOVERY): usn = 10
SYS@ora10g> select * from v$rollname;
ERROR:
ORA-03114: not connected to ORACLE
SYS@ora10g> conn / as sysdba;
Connected to an idle instance.
SYS@ora10g> startup mount
ORACLE instance started.
Total System Global Area 524288000 bytes
Fixed Size
1220384 bytes
Variable Size
327155936 bytes
Database Buffers 192937984 bytes
Redo Buffers
2973696 bytes
Database mounted.
SYS@ora10g> select * from v$rollname;
select * from V$rollname
*
ERROR at line 1:
ORA-01219: database not open: queries allowed on fixed tables/views only
SYS@ora10g> select segment_name from dba_rollback_segs;
select segment_name from dba_rollback_segs
*
ERROR at line 1:
ORA-01219: database not open: queries allowed on fixed tables/views only
此时通过改动pfile參数文件，然后将undo_management='AUTO'改为undo_management='MANUAL';
并加入隐含參数"_corrupted_rollback_segments"。即加入下面内容到pfile文件里：
_corrupted_rollback_segments='_SYSSMU1$','_SYSSMU2$','_SYSSMU3$','_SYSSMU4$','_SYSSMU5$','_SYSSMU6$','_SYSSMU7$','_SYSSMU8$','_SYSSMU9$','_SYSSMU10$'
目的是将undo管理方式改为手动。并标记这10个默认的回滚段为损坏，然后再用该pfile启动数据库
SYS@ora10g> shutdown abort
ORACLE instance shut down.
SYS@ora10g> startup pfile=/u01/app/oracle/product/10.2.0/db_1/dbs/initora10g.ora
ORACLE instance started.
Total System Global Area 524288000 bytes
Fixed Size
1220384 bytes
Variable Size
327155936 bytes
Database Buffers 192937984 bytes
Redo Buffers
2973696 bytes
Database mounted.
Database opened.
SYS@ora10g>
SYS@ora10g> conn zlm/zlm
Connected.
ZLM@ora10g> select count(*) from t1;
COUNT(*)
----------
20
此时数据库已经可以打开，连接到非系统用户zlm，确认新增的10条数据已经丢失
ZLM@ora10g> select * from v$rollname;
USN NAME
---------- ------------------------------
0 SYSTEM
ZLM@ora10g> select segment_name from dba_rollback_segs;
SEGMENT_NAME
------------------------------
SYSTEM
_SYSSMU1$
_SYSSMU2$
_SYSSMU3$
_SYSSMU4$
_SYSSMU5$
_SYSSMU6$
_SYSSMU7$
_SYSSMU8$
_SYSSMU9$
_SYSSMU10$
11 rows selected.
因为数据库已经正常open,如今回滚段如今已经能够查询到了
还须要将原undo表空间删除并重建，否则还是会有问题，如:非系统用户无法使用系统回滚段
ZLM@ora10g> insert into t1 select * from dba_objects where rownum<11;
insert into t1 select * from dba_objects where rownum<11
*
ERROR at line 1:
ORA-01552: cannot use system rollback segment for non-system tablespace 'ZLM'
ZLM@ora10g> conn / as sysdba
Connected.
SYS@ora10g> insert into zlm.t1 select * from dba_objects where rownum<11;
insert into zlm.t1 select * from dba_objects where rownum<11
*
ERROR at line 1:
ORA-01552: cannot use system rollback segment for non-system tablespace 'ZLM'
--重建UNDO表空间（先删除，后创建）
SYS@ora10g> show parameter undo
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
undo_management string
MANUAL
undo_retention
integer 900
undo_tablespace string
UNDOTBS1
SYS@ora10g> set line 130 pages 130
SYS@ora10g> col file_name for a80
SYS@ora10g> col tablespace_name for a15
SYS@ora10g> select file_name,tablespace_name from dba_data_files;
FILE_NAME
TABLESPACE_NAME
-------------------------------------------------------------------------------- ---------------
/u01/app/oracle/oradata/ora10g/zlm01.dbf ZLM
/u01/app/oracle/oradata/ora10g/example01.dbf EXAMPLE
/u01/app/oracle/oradata/ora10g/users01.dbf USERS
/u01/app/oracle/oradata/ora10g/sysaux01.dbf SYSAUX
/u01/app/oracle/oradata/ora10g/undotbs01.dbf UNDOTBS1
/u01/app/oracle/oradata/ora10g/system01.dbf SYSTEM
6 rows selected.
SYS@ora10g> drop tablespace undotbs1 including contents and datafiles;
Tablespace dropped.
SYS@ora10g> select file_name,tablespace_name from dba_data_files;
FILE_NAME
TABLESPACE_NAME
-------------------------------------------------------------------------------- ---------------
/u01/app/oracle/oradata/ora10g/zlm01.dbf ZLM
/u01/app/oracle/oradata/ora10g/example01.dbf EXAMPLE
/u01/app/oracle/oradata/ora10g/users01.dbf USERS
/u01/app/oracle/oradata/ora10g/sysaux01.dbf SYSAUX
/u01/app/oracle/oradata/ora10g/system01.dbf SYSTEM
SYS@ora10g> create undo tablespace undotbs1 datafile '/u01/app/oracle/oradata/ora10g/undotbs01.dbf' size 50m reuse autoextend on next 10m;
Tablespace created.
--关闭数据库。将pfile中添加的參数去除。并改回undo_management='AUTO'后，用pfile启动数据库
SYS@ora10g> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SYS@ora10g> startup pfile=/u01/app/oracle/product/10.2.0/db_1/dbs/initora10g.ora
ORACLE instance started.
Total System Global Area 524288000 bytes
Fixed Size
1220384 bytes
Variable Size
327155936 bytes
Database Buffers 192937984 bytes
Redo Buffers
2973696 bytes
Database mounted.
Database opened.
SYS@ora10g> create spfile from pfile;
File created.
SYS@ora10g> show parameter spfile
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
spfile string
SYS@ora10g> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SYS@ora10g> startup
ORACLE instance started.
Total System Global Area 524288000 bytes
Fixed Size
1220384 bytes
Variable Size
327155936 bytes
Database Buffers 192937984 bytes
Redo Buffers
2973696 bytes
Database mounted.
Database opened.
SYS@ora10g> show parameter spfile
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
spfile string /u01/app/oracle/product/10.2.0
/db_1/dbs/spfileora10g.ora
SYS@ora10g> conn zlm/zlm
Connected.
ZLM@ora10g> select count(*) from t1;
COUNT(*)
----------
20
ZLM@ora10g> insert into t1 select * from dba_objects where rownum<11;
10 rows created.
ZLM@ora10g> select count(*) from t1;
COUNT(*)
----------
30
ZLM@ora10g>
最后用改动完的pfile再创建spfile并启动数据库，非系统用户已经可以使用系统回滚段来进行DML事务操作了
总结：
仅仅要非当前的在线日志文件内容未丢失（开启归档，并正常关闭数据库）的情况下，数据库的数据就不会丢失（当然，归档文件也被删除的例外）。非在线的能够通过CLEAR又一次创建，在线的仅仅要是正常关闭的。就会被写到归档文件里去。通过RECOVER DATABASE UNTIL CANCEL就能够还原数据。最坏的情况就是current的在线日志在数据库意外关闭的情况下丢失。这样的情况丢数据在所难免。假设丢数据的范围是可接受的，那么能够通过设置_allow_resetlogs_corruption=true，就能够强行OPEN数据库。可是会存在一定的问题，11g通过open
resetlogs应该是能够直接OPEN数据库的。打开后要对数据库做一个全备，而10g通过该隐含參数OPEN数据库后，会遭遇到ORA-600 [4194]的错误，须要设置undo_management=manual,并通过隐含參数_corrupted_rollback_segments='_SYSSMU1$',...,'_SYSSMU10$'将系统回滚段设置为损坏，并重建默认的UNDO表空间后，数据库才干OPEN并正常使用。相同地，打开库以后第一件事就是对数据库做一个完备。