什么情况可能使用该参数
有些时侯可能你的库处于非归档的模式下，而你的联机重做日志又currupted,你的数据文件不能完成完全的恢复。而这时当你试图打开数据库时，oracle提示你用resetlogs选项，当你使用该选项时oracle又不允许你使用该选项，总之你想打开数据库，可就是打不开。
1、最好做一个物理的库的全备
2、使用sqlplus 启动库至mount
sqlplus /nolog
sql>connect internal
sql>startup mount
3、确保所有的数据文件都处于"END BACKUP"状态
sql>set pages 0 feedback off lines 132
sql>spool alter_df.sql
sql>SELECT ‘alter database datafile ‘||file_name||‘ END BACKUP;‘ from v$datafile;
sql>spool off
sql>@alter_df.sql
4、试着打开数据库
sql>alter database open;
如数据库成功打开，余下的都不需要做了，到此为止
5、如果你在打开时被要求进行恢复，使用"UNTIL CANCEL"这种进行恢复,然后再发出ALTER DATABASE OPEN RESETLOGS这个命令
sql>recover database until cancel;
sql>alter database open resetlogs;
6、如果数据库仍不能打开，把库down掉
sql>shutdown immediate
7、在init.ora中加入如下参数
_allow_resetlogs_corruption=TRUE
8、执行如下语句
sql>connect internal
sql>startup mount
sql>@alter_df.sql
sql>alter database open
9、如在alter database open时仍旧报错，使用until cancel恢复
sql>recover database until cancel;
sql>alter database open resetlogs;
10、经过"9",数据库一定被打开了，数据库被打开后，马上执行一个full export
11、down掉库,去掉_all_resetlogs_corrupt参数
12、重建库
13、import并完成恢复
14、建议执行一下ANALYZE TABLE ...VALIDATE STRUCTURE CASCADE;
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作者：茄肥猫
来源：CSDN
原文：https://blog.csdn.net/lively1982/article/details/18267241
版权声明：本文为博主原创文章，转载请附上博文链接！
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使用_allow_resetlogs_corruption 打开无归档日志 rman 备份库，运维DBA反映服务器宕机后，开启数据库报错ORA-01194 ORA-01110，
分析原因为Oracle SCN不一致导致数据库无法启动，使用 _allow_resetlogs_corruption 打开数据库
1.rman还原恢复操作
--还原数据库 RMAN> restore database; --恢复数据库 RMAN> recover database; Starting recover at 2012-03-08 21:20:45 using target database control file instead of recovery catalog allocated channel: ORA_DISK_1 channel ORA_DISK_1: SID=65 device type=DISK starting media recovery RMAN-00571: =========================================================== RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS =============== RMAN-00571: =========================================================== RMAN-03002: failure of recover command at 03/08/2012 21:20:47 RMAN-06053: unable to perform media recovery because of missing log RMAN-06025: no backup of archived log for thread 1 with sequence 2936 and starting SCN of 25991695 found to restore RMAN-06025: no backup of archived log for thread 1 with sequence 2935 and starting SCN of 25991652 found to restore RMAN-06025: no backup of archived log for thread 1 with sequence 2934 and starting SCN of 25991649 found to restore …………………… RMAN-06025: no backup of archived log for thread 1 with sequence 2902 and starting SCN of 25991156 found to restore 这里报日志缺少，实际上是备份的数据库文件后，没有备份归档日志，归档日志全部丢失
进行不完全恢复
SQL> recover database until cancel;
ORA-00279: change 25991194 generated at 03/08/2012 20:33:58 needed for thread 1
ORA-00289: suggestion : /opt/oracle/oradata/archivelog/chf/1_2902_752334071.dbf
ORA-00280: change 25991194 for thread 1 is in sequence #2902
Specify log: {=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: ‘/opt/oracle/oradata/chf/system01.dbf‘
ORA-01112: media recovery not started
SQL> alter database open resetlogs;
alter database open resetlogs
*
ERROR at line 1:
ORA-01194: file 1 needs more recovery to be consistent
ORA-01110: data file 1: ‘/opt/oracle/oradata/chf/system01.dbf‘
2.查看相关SCN
SQL> select file#,to_char(checkpoint_change#,‘999999999999‘) from v$datafile;
FILE# TO_CHAR(CHECK
---------- -------------
1 25992214
2 25992214
3 25992214
4 25992214
5 25992214
6 25992214
7 25992214
8 25992214
9 25992214
10 25992214
11 25992214
FILE# TO_CHAR(CHECK
---------- -------------
13 25992214
14 25992214
13 rows selected.
SQL> select file#,online_status,to_char(change#,‘999999999999‘) from v$recover_file;
FILE# ONLINE_ TO_CHAR(CHANG
---------- ------- -------------
1 ONLINE 25991194
2 ONLINE 25991194
3 ONLINE 25991194
4 ONLINE 25991194
5 ONLINE 25991194
6 ONLINE 25991194
7 ONLINE 25991194
8 ONLINE 25991194
9 ONLINE 25991194
10 ONLINE 25991194
11 ONLINE 25991194
FILE# ONLINE_ TO_CHAR(CHANG
---------- ------- -------------
13 ONLINE 25991194
14 ONLINE 25991194
13 rows selected.
SQL> select file#,to_char(checkpoint_change#,‘999999999999‘) from v$datafile_header;
FILE# TO_CHAR(CHECK
---------- -------------
1 25991194
2 25991194
3 25991194
4 25991194
5 25991194
6 25991194
7 25991194
8 25991194
9 25991194
10 25991194
11 25991194
FILE# TO_CHAR(CHECK
---------- -------------
13 25991194
14 25991194
13 rows selected.
--发现数据文件scn和控制文件不一致，重建控制文件，然后查询相关scn
SQL> select file#,to_char(checkpoint_change#,‘999999999999‘) from v$datafile;
FILE# TO_CHAR(CHECK
---------- -------------
1 25991194
2 25991194
3 25991194
4 25991194
5 25991194
6 25991194
7 25991194
8 25991194
9 25991194
10 25991194
11 25991194
FILE# TO_CHAR(CHECK
---------- -------------
13 25991194
14 25991194
13 rows selected.
SQL> select file#,online_status,to_char(change#,‘999999999999‘) from v$recover_file;
FILE# ONLINE_ TO_CHAR(CHANG
---------- ------- -------------
1 ONLINE 25991194
2 ONLINE 25991194
3 ONLINE 25991194
4 ONLINE 25991194
5 ONLINE 25991194
6 ONLINE 25991194
7 ONLINE 25991194
8 ONLINE 25991194
9 ONLINE 25991194
10 ONLINE 25991194
11 ONLINE 25991194
FILE# ONLINE_ TO_CHAR(CHANG
---------- ------- -------------
13 ONLINE 25991194
14 ONLINE 25991194
13 rows selected.
SQL> select file#,to_char(checkpoint_change#,‘999999999999‘) from v$datafile_header;
FILE# TO_CHAR(CHECK
---------- -------------
1 25991194
2 25991194
3 25991194
4 25991194
5 25991194
6 25991194
7 25991194
8 25991194
9 25991194
10 25991194
11 25991194
FILE# TO_CHAR(CHECK
---------- -------------
13 25991194
14 25991194
13 rows selected.
--此时所有scn均一致
3.尝试打开数据库
SQL> alter database open resetlogs;
alter database open resetlogs
*
ERROR at line 1:
ORA-01194: file 1 needs more recovery to be consistent
ORA-01110: data file 1: ‘/opt/oracle/oradata/chf/system01.dbf‘
SQL> recover database using backup controlfile until cancel;
ORA-00279: change 25991194 generated at 03/08/2012 20:33:58 needed for thread 1
ORA-00289: suggestion : /opt/oracle/oradata/archivelog/chf/1_2902_752334071.dbf
ORA-00280: change 25991194 for thread 1 is in sequence #2902
Specify log: {=suggested | filename | AUTO | CANCEL}
cancel
ORA-01547: warning: RECOVER succeeded but OPEN RESETLOGS would get error below
ORA-01194: file 1 needs more recovery to be consistent
ORA-01110: data file 1: ‘/opt/oracle/oradata/chf/system01.dbf‘
ORA-01112: media recovery not started
SQL> alter database open resetlogs;
alter database open resetlogs
*
ERROR at line 1:
ORA-01194: file 1 needs more recovery to be consistent
ORA-01110: data file 1: ‘/opt/oracle/oradata/chf/system01.dbf‘
5.使用隐含参数打开数据库
SQL> create pfile=‘/tmp/pfile‘ from spfile; File created. -------/tmp/pfile中加上---------- _allow_resetlogs_corruption= TRUE --------------------------------- SQL> startup mount pfile=‘/tmp/pfile‘ force ORACLE instance started. Total System Global Area 622149632 bytes Fixed Size 2230912 bytes Variable Size 419431808 bytes Database Buffers 192937984 bytes Redo Buffers 7548928 bytes Database mounted. SQL> alter database open resetlogs; Database altered. SQL> select open_mode from v$database; OPEN_MODE -------------------- READ WRITE
总结
这次的试验没有多少实际意义，但是可以说明几个问题：
1.所有的数据文件的scn都一致，甚至和控制文件的也一致，数据库不一定可以open成功
(怀疑是数据文件中的scn大于data header scn)
2.对于这样的问题，如果使用bbed修改所有数据文件header的scn不知道是否可以解决
3.如果rman只备份了数据文件而没有任何一个归档日志，数据库通过隐含参数还是可以open，抢救数据
原文地址：https://www.cnblogs.com/chendian0/p/10319426.html