oracle BBED-数据库文件头恢复

一,场景模拟

　　01,场景复现

　　

 

 

 　　大概就是先备份一个文件,然后进行归档切换操作,完成后再把旧的system01文件拷贝回去,这样的话system 就是一个旧的时间段了,启动肯定是会报错的.

　　

 

 

 　 查询数据库的scn号看看

　　

 

 

 　似乎看起来没什么变化

　 查看表头试试?

　 

 

 

 　发现有些不一样, 数据库open 的时候是会检测这个表头信息的,不一致的话肯定开启不了 。

二，问题处理

　　01，文件头说明

　　　　因为我们要修改数据文件头，因此我们需要关注四个偏移量offset点，分别为484、492、140和148
　　　　1、datafile 的file header 存储在第一个block里
　　　　2、Oracle considers four attributes of this data structure when determining if a datafile is sync with the other data files of the database:（不同oracle版本offset可能不同）
　　　　  （1）kscnbas (at offset 484) – SCN of last change to the datafile.
                （2）kcvcptim (at offset 492) -Time of the last change to the datafile.
                （3）kcvfhcpc (at offset 140) – Checkpoint count.
                （4）kcvfhccc (at offset 148) – Unknown, but is always 1 less than thecheckpoint point count.
                   Oracle有4个属性来判断datafile 是否和其他的datafile 一致，如果都一致，可以正常操作，如果不一致，那么会报ORA-01113错误

　　 02， 文件头对比查看

　　　　正常文件头信息：

  1 BBED> set filename '/u01/app/oracle/oradata/oracle01/users01.dbf'
  2     FILENAME           /u01/app/oracle/oradata/oracle01/users01.dbf
  3 
  4 BBED>  set offset 494
  5     OFFSET             494
  6 
  7 BBED> dump
  8  File: /u01/app/oracle/oradata/oracle01/users01.dbf (4)
  9  Block: 1                Offsets:  494 to 1005           Dba:0x01000001
 10 ------------------------------------------------------------------------
 11  ab3e0100 bdc8c301 00000200 00001000 00000200 00000000 00000000 00000000
 12  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 13  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 14  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 15  00000000 00000000 00000000 00000000 00000000 00000d00 0d000d00 01000000
 16  00000000 00000000 00000200 000153b0 fe040000 00000000 00000000 00000000
 17  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 18  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 19  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 20  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 21  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 22  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 23  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 24  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 25  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 26  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 27 
 28  <32 bytes per line>
 29 
 30 BBED>  set offset 492
 31     OFFSET             492
 32 
 33 BBED> dump
 34  File: /u01/app/oracle/oradata/oracle01/users01.dbf (4)
 35  Block: 1                Offsets:  492 to 1003           Dba:0x01000001
 36 ------------------------------------------------------------------------
 37  0bb1ab3e 0100bdc8 c3010000 02000000 10000000 02000000 00000000 00000000
 38  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 39  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 40  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 41  00000000 00000000 00000000 00000000 00000000 00000000 0d000d00 0d000100
 42  00000000 00000000 00000000 02000001 53b0fe04 00000000 00000000 00000000
 43  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 44  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 45  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 46  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 47  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 48  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 49  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 50  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 51  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 52  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 53 
 54  <32 bytes per line>
 55 
 56 BBED> set offset 140
 57     OFFSET             140
 58 
 59 BBED> dump
 60  File: /u01/app/oracle/oradata/oracle01/users01.dbf (4)
 61  Block: 1                Offsets:  140 to  651           Dba:0x01000001
 62 ------------------------------------------------------------------------
 63  d5d39f3e 13d29f3e d4d39f3e 0dbe7900 00000000 f121fa3b 0100eb1f 34050000
 64  02000000 10000000 02000000 00000000 00000000 00000000 00000000 00000000
 65  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 66  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 67  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 68  00000000 00000000 00000000 80020000 00000000 00000000 00000000 00000000
 69  04000000 05005553 45525300 00000000 00000000 00000000 00000000 00000000
 70  00000000 04000000 00000000 00000000 00000000 00000000 00000000 00000000
 71  00000000 00000000 00000000 00000000 00000000 3ef4503e 374f9504 00000000
 72  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 73  00000000 00000000 00000000 00000000 00000000 00000000 c0f41a05 00006909
 74  0bb1ab3e 0100bdc8 c3010000 02000000 10000000 02000000 00000000 00000000
 75  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 76  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 77  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 78  00000000 00000000 00000000 00000000 00000000 00000000 0d000d00 0d000100
 79 
 80  <32 bytes per line>
 81 
 82 BBED> set offset 148
 83     OFFSET             148
 84 
 85 BBED> dump
 86  File: /u01/app/oracle/oradata/oracle01/users01.dbf (4)
 87  Block: 1                Offsets:  148 to  659           Dba:0x01000001
 88 ------------------------------------------------------------------------
 89  d4d39f3e 0dbe7900 00000000 f121fa3b 0100eb1f 34050000 02000000 10000000
 90  02000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 91  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 92  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 93  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 94  00000000 80020000 00000000 00000000 00000000 00000000 04000000 05005553
 95  45525300 00000000 00000000 00000000 00000000 00000000 00000000 04000000
 96  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 97  00000000 00000000 00000000 3ef4503e 374f9504 00000000 00000000 00000000
 98  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 99  00000000 00000000 00000000 00000000 c0f41a05 00006909 0bb1ab3e 0100bdc8
100  c3010000 02000000 10000000 02000000 00000000 00000000 00000000 00000000
101  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
102  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
103  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
104  00000000 00000000 00000000 00000000 0d000d00 0d000100 00000000 00000000
105 
106  <32 bytes per line>

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