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如何使用BBED

BBED是Oracle提供的块编辑器,借助BBED我们可以更好的理解Oracle的Block的结构。也只有理解了块的结构,才能更好的利用BBED在某些特殊情况下修复数据库。

BBED使用原则
   A.确认大端、小端问题。这个确认后,更改数据后才不会出错。
   B.在正确的位置修改正确的值。确认需要修改的值的位置,确认你需要修改什么成什么值。
如何判断大端、小端?
   BBED> p kcvfhbfh
   struct kcvfhbfh, 20 bytes                   @0       
      ub1 type_kcbh                            @0        0x0b
      ub1 frmt_kcbh                            @1        0xa2
      ub1 spare1_kcbh                          @2        0x00
      ub1 spare2_kcbh                          @3        0x00
      ub4 rdba_kcbh                            @4        0x00400001
      ub4 bas_kcbh                             @8        0x00000000
      ub2 wrp_kcbh                             @12       0x0000
      ub1 seq_kcbh                             @14       0x01
      ub1 flg_kcbh                             @15       0x04 (KCBHFCKV)
      ub2 chkval_kcbh                          @16       0x7c2e
      ub2 spare3_kcbh                          @18       0x0000
   
   BBED> d/v count 20
    File: /oradata/ora10/system01.dbf (1)
    Block: 1       Offsets:    0 to   19  Dba:0x00400001
   -------------------------------------------------------
    0ba20000 01004000 00000000 00000104 l ....@.........
    2e7c0000                            l .|..
   
    <16 bytes per line>
   
   BBED>
如果红色部分显示的内容一样,则说明是大端,如果不一样,则是小端

如果是Little Endian,如果将0x00400001修改为0x00400002,应该用m/x 02004000 offset 4

如果是Big   Endian如果将0x00400001修改为0x00400002,应该用m/x 00400002 offset 4


10g块头结构

BBED> p kcvfh
struct kcvfh, 676 bytes                     @0       
   struct kcvfhbfh, 20 bytes                @0       
      ub1 type_kcbh                         @0        0x0b
      ub1 frmt_kcbh                         @1        0xa2
      ub1 spare1_kcbh                       @2        0x00
      ub1 spare2_kcbh                       @3        0x00
      ub4 rdba_kcbh                         @4        0x00400001
      ub4 bas_kcbh                          @8        0x00000000
      ub2 wrp_kcbh                          @12       0x0000
      ub1 seq_kcbh                          @14       0x01
      ub1 flg_kcbh                          @15       0x04 (KCBHFCKV)
      ub2 chkval_kcbh                       @16       0x73a8
      ub2 spare3_kcbh                       @18       0x0000
   struct kcvfhhdr, 76 bytes                @20      
      ub4 kccfhswv                          @20       0x00000000
      ub4 kccfhcvn                          @24       0x0a200100
      ub4 kccfhdbi                          @28       0x3526cf91
      text kccfhdbn[0]                      @32      O
      text kccfhdbn[1]                      @33      R
      text kccfhdbn[2]                      @34      A
      text kccfhdbn[3]                      @35      1
      text kccfhdbn[4]                      @36      0
      text kccfhdbn[5]                      @37       
      text kccfhdbn[6]                      @38       
      text kccfhdbn[7]                      @39       
      ub4 kccfhcsq                          @40       0x0000018e
      ub4 kccfhfsz                          @44       0x0000f000
      s_blkz kccfhbsz                       @48       0x00
      ub2 kccfhfno                          @52       0x0001
      ub2 kccfhtyp                          @54       0x0003
      ub4 kccfhacid                         @56       0x00000000
      ub4 kccfhcks                          @60       0x00000000
      text kccfhtag[0]                      @64       
      text kccfhtag[1]                      @65       
      text kccfhtag[2]                      @66       
      text kccfhtag[3]                      @67       
      text kccfhtag[4]                      @68       
      text kccfhtag[5]                      @69       
      text kccfhtag[6]                      @70       
      text kccfhtag[7]                      @71       
      text kccfhtag[8]                      @72       
      text kccfhtag[9]                      @73       
      text kccfhtag[10]                     @74       
      text kccfhtag[11]                     @75       
      text kccfhtag[12]                     @76       
      text kccfhtag[13]                     @77       
      text kccfhtag[14]                     @78       
      text kccfhtag[15]                     @79       
      text kccfhtag[16]                     @80       
      text kccfhtag[17]                     @81       
      text kccfhtag[18]                     @82       
      text kccfhtag[19]                     @83       
      text kccfhtag[20]                     @84       
      text kccfhtag[21]                     @85       
      text kccfhtag[22]                     @86       
      text kccfhtag[23]                     @87       
      text kccfhtag[24]                     @88       
      text kccfhtag[25]                     @89       
      text kccfhtag[26]                     @90       
      text kccfhtag[27]                     @91       
      text kccfhtag[28]                     @92       
      text kccfhtag[29]                     @93       
      text kccfhtag[30]                     @94       
      text kccfhtag[31]                     @95       
   ub4 kcvfhrdb                             @96       0x00400179
   struct kcvfhcrs, 8 bytes                 @100     
      ub4 kscnbas                           @100      0x00000008
      ub2 kscnwrp                           @104      0x0000
   ub4 kcvfhcrt                             @108      0x221e01bf
   ub4 kcvfhrlc                             @112      0x36303713
   struct kcvfhrls, 8 bytes                 @116     
      ub4 kscnbas                           @116      0x00080634
      ub2 kscnwrp                           @120      0x0000
   ub4 kcvfhbti                             @124      0x00000000
   struct kcvfhbsc, 8 bytes                 @128     
      ub4 kscnbas                           @128      0x00000000
      ub2 kscnwrp                           @132      0x0000
   ub2 kcvfhbth                             @136      0x0000
   ub2 kcvfhsta                             @138      0x2000 (NONE)
   struct kcvfhckp, 36 bytes                @484     
      struct kcvcpscn, 8 bytes              @484     
         ub4 kscnbas                        @484      0x00088742
         ub2 kscnwrp                        @488      0x0000
      ub4 kcvcptim                          @492      0x36304031
      ub2 kcvcpthr                          @496      0x0001
      union u, 12 bytes                     @500     
         struct kcvcprba, 12 bytes          @500     
            ub4 kcrbaseq                    @500      0x00000002
            ub4 kcrbabno                    @504      0x00015b11
            ub2 kcrbabof                    @508      0x0010
      ub1 kcvcpetb[0]                       @512      0x02
      ub1 kcvcpetb[1]                       @513      0x00
      ub1 kcvcpetb[2]                       @514      0x00
      ub1 kcvcpetb[3]                       @515      0x00
      ub1 kcvcpetb[4]                       @516      0x00
      ub1 kcvcpetb[5]                       @517      0x00
      ub1 kcvcpetb[6]                       @518      0x00
      ub1 kcvcpetb[7]                       @519      0x00
   ub4 kcvfhcpc                             @140      0x00000033
   ub4 kcvfhrts                             @144      0x3630370c
   ub4 kcvfhccc                             @148      0x00000032
   struct kcvfhbcp, 36 bytes                @152     
      struct kcvcpscn, 8 bytes              @152     
         ub4 kscnbas                        @152      0x00000000
         ub2 kscnwrp                        @156      0x0000
      ub4 kcvcptim                          @160      0x00000000
      ub2 kcvcpthr                          @164      0x0000
      union u, 12 bytes                     @168     
         struct kcvcprba, 12 bytes          @168     
            ub4 kcrbaseq                    @168      0x00000000
            ub4 kcrbabno                    @172      0x00000000
            ub2 kcrbabof                    @176      0x0000
      ub1 kcvcpetb[0]                       @180      0x00
      ub1 kcvcpetb[1]                       @181      0x00
      ub1 kcvcpetb[2]                       @182      0x00
      ub1 kcvcpetb[3]                       @183      0x00
      ub1 kcvcpetb[4]                       @184      0x00
      ub1 kcvcpetb[5]                       @185      0x00
      ub1 kcvcpetb[6]                       @186      0x00
      ub1 kcvcpetb[7]                       @187      0x00
   ub4 kcvfhbhz                             @312      0x00000000
   struct kcvfhxcd, 16 bytes                @316     
      ub4 space_kcvmxcd[0]                  @316      0x00000000
      ub4 space_kcvmxcd[1]                  @320      0x00000000
      ub4 space_kcvmxcd[2]                  @324      0x00000000
      ub4 space_kcvmxcd[3]                  @328      0x00000000
   word kcvfhtsn                            @332      0
   ub2 kcvfhtln                             @336      0x0006
   text kcvfhtnm[0]                         @338     S
   text kcvfhtnm[1]                         @339     Y
   text kcvfhtnm[2]                         @340     S
   text kcvfhtnm[3]                         @341     T
   text kcvfhtnm[4]                         @342     E
   text kcvfhtnm[5]                         @343     M
   text kcvfhtnm[6]                         @344      
   text kcvfhtnm[7]                         @345      
   text kcvfhtnm[8]                         @346      
   text kcvfhtnm[9]                         @347      
   text kcvfhtnm[10]                        @348      
   text kcvfhtnm[11]                        @349      
   text kcvfhtnm[12]                        @350      
   text kcvfhtnm[13]                        @351      
   text kcvfhtnm[14]                        @352      
   text kcvfhtnm[15]                        @353      
   text kcvfhtnm[16]                        @354      
   text kcvfhtnm[17]                        @355      
   text kcvfhtnm[18]                        @356      
   text kcvfhtnm[19]                        @357      
   text kcvfhtnm[20]                        @358      
   text kcvfhtnm[21]                        @359      
   text kcvfhtnm[22]                        @360      
   text kcvfhtnm[23]                        @361      
   text kcvfhtnm[24]                        @362      
   text kcvfhtnm[25]                        @363      
   text kcvfhtnm[26]                        @364      
   text kcvfhtnm[27]                        @365      
   text kcvfhtnm[28]                        @366      
   text kcvfhtnm[29]                        @367      
   ub4 kcvfhrfn                             @368      0x00000001
   struct kcvfhrfs, 8 bytes                 @372     
      ub4 kscnbas                           @372      0x00000000
      ub2 kscnwrp                           @376      0x0000
   ub4 kcvfhrft                             @380      0x00000000
   struct kcvfhafs, 8 bytes                 @384     
      ub4 kscnbas                           @384      0x00000000
      ub2 kscnwrp                           @388      0x0000
   ub4 kcvfhbbc                             @392      0x00000000
   ub4 kcvfhncb                             @396      0x00000000
   ub4 kcvfhmcb                             @400      0x00000000
   ub4 kcvfhlcb                             @404      0x00000000
   ub4 kcvfhbcs                             @408      0x00000000
   ub2 kcvfhofb                             @412      0x000a
   ub2 kcvfhnfb                             @414      0x000a
   ub4 kcvfhprc                             @416      0x221e01a8
   struct kcvfhprs, 8 bytes                 @420     
      ub4 kscnbas                           @420      0x00000001
      ub2 kscnwrp                           @424      0x0000
   struct kcvfhprfs, 8 bytes                @428     
      ub4 kscnbas                           @428      0x00000000
      ub2 kscnwrp                           @432      0x0000
   ub4 kcvfhtrt                             @444      0x00000000

BBED> 

SET帮助信息
BBED> help set
SET DBA [ dba | file#, block# ]                    --设置块的地址
SET FILENAME 'filename'                            --设置要查看的数据文件名字
SET FILE file#                                     --设置要查看的文件编号
SET BLOCK [+/-]block#                              --设置块的编号
   BBED> set block +4
           BLOCK#          5
   
   BBED> set block -1
           BLOCK#          4
   
   BBED> 

SET OFFSET [ [+/-]byte offset | symbol | *symbol ] --设置在当前块中偏移量
   BBED> set offset -10
           OFFSET          10
   
   BBED> set offset +40
           OFFSET          50
   
   BBED> 

SET BLOCKSIZE bytes                             --设置块大小
SET LIST[FILE] 'filename'                       --设置包含数据文件的文件列表
SET WIDTH character_count                       --设置每行显示的字符宽度
SET COUNT bytes_to_display                      --设置显示字符的个数
SET IBASE [ HEX | OCT | DEC ]                   --设置输入的模式,16/8/10进制
SET OBASE [ HEX | OCT | DEC ]                   --设置输出的模式,16/8/10进制
SET MODE  [ BROWSE | EDIT ]                     --设置模式,只读或编辑
SET SPOOL [ Y | N ]                             --设置为Y,会把输入写入bbed.log

SHOW [ <SET parameter> | ALL ]

显示当前BBED相关配置信息

BBED> show
        FILE#           1
        BLOCK#          1
        OFFSET          0
        DBA             0x00400001 (4194305 1,1)
        FILENAME        /oradata/ora10/system01.dbf
        BIFILE          bifile.bbd
        LISTFILE        files.txt
        BLOCKSIZE       8192
        MODE            Browse
        EDIT            Unrecoverable
        IBASE           Dec
        OBASE           Dec
        WIDTH           80
        COUNT           10
        LOGFILE         log.bbd
        SPOOL           No

BBED> 

INFO

显示当前的listfile内容,列出要查看或编辑的文件列表

BBED> info
 File#  Name                                                        Size(blks)
 -----  ----                                                        ----------
     1  /oradata/ora10/system01.dbf                                          0
     2  /oradata/ora10/undotbs01.dbf                                         0
     3  /oradata/ora10/sysaux01.dbf                                          0
     4  /oradata/ora10/users01.dbf                                           0
     5  /oradata/ora10/example01.dbf                                         0

BBED> 

MAP[/v] [ DBA | FILENAME | FILE | BLOCK ]         

显示当前块结构并显示结构体的每个字段,用/v会显示更详细。会显示部分块类型的结构,比如数据文件头部,table/index/undo块等信息  

BBED> map /v
 File: /oradata/ora10/system01.dbf (1)
 Block: 1                                     Dba:0x00400001
------------------------------------------------------------
 Data File Header

 struct kcvfh, 676 bytes                    @0       
    struct kcvfhbfh, 20 bytes               @0       
    struct kcvfhhdr, 76 bytes               @20      
    ub4 kcvfhrdb                            @96      
    struct kcvfhcrs, 8 bytes                @100     
    ub4 kcvfhcrt                            @108     
    ub4 kcvfhrlc                            @112     
    struct kcvfhrls, 8 bytes                @116     
    ub4 kcvfhbti                            @124     
    struct kcvfhbsc, 8 bytes                @128     
    ub2 kcvfhbth                            @136     
    ub2 kcvfhsta                            @138     
    struct kcvfhckp, 36 bytes               @484     
    ub4 kcvfhcpc                            @140     
    ub4 kcvfhrts                            @144     
    ub4 kcvfhccc                            @148     
    struct kcvfhbcp, 36 bytes               @152     
    ub4 kcvfhbhz                            @312     
    struct kcvfhxcd, 16 bytes               @316     
    word kcvfhtsn                           @332     
    ub2 kcvfhtln                            @336     
    text kcvfhtnm[30]                       @338     
    ub4 kcvfhrfn                            @368     
    struct kcvfhrfs, 8 bytes                @372     
    ub4 kcvfhrft                            @380     
    struct kcvfhafs, 8 bytes                @384     
    ub4 kcvfhbbc                            @392     
    ub4 kcvfhncb                            @396     
    ub4 kcvfhmcb                            @400     
    ub4 kcvfhlcb                            @404     
    ub4 kcvfhbcs                            @408     
    ub2 kcvfhofb                            @412     
    ub2 kcvfhnfb                            @414     
    ub4 kcvfhprc                            @416     
    struct kcvfhprs, 8 bytes                @420     
    struct kcvfhprfs, 8 bytes               @428     
    ub4 kcvfhtrt                            @444     
 ub4 tailchk                                @8188    

BBED>      
                                                                                                  

DUMP[/v] [ DBA | FILENAME | FILE | BLOCK | OFFSET | COUNT ]

显示数据库的内容,/v显示更易读

    BBED> d/v dba 1,1 count 16
     File: /oradata/ora10/system01.dbf (1)
     Block: 1       Offsets:    0 to   15  Dba:0x00400001
    -------------------------------------------------------
     0ba20000 01004000 00000000 00000104 l ....@.........
    
     <16 bytes per line>
    
    BBED> d/v filename '/oradata/ora10/system01.dbf' count 16
     File: /oradata/ora10/system01.dbf (1)
     Block: 1       Offsets:    0 to   15  Dba:0x00400001
    -------------------------------------------------------
     0ba20000 01004000 00000000 00000104 l ....@.........
    
     <16 bytes per line>
    
    BBED> dump /v file 1 count 16
     File: /oradata/ora10/system01.dbf (1)
     Block: 1       Offsets:    0 to   15  Dba:0x00400001
    -------------------------------------------------------
     0ba20000 01004000 00000000 00000104 l ....@.........
    
     <16 bytes per line>
    
    BBED> dump/v block 1 count 16
     File: /oradata/ora10/system01.dbf (1)
     Block: 1       Offsets:    0 to   15  Dba:0x00400001
    -------------------------------------------------------
     0ba20000 01004000 00000000 00000104 l ....@.........
    
     <16 bytes per line>
    
    BBED> d/v offset 0 count 16
     File: /oradata/ora10/system01.dbf (1)
     Block: 1       Offsets:    0 to   15  Dba:0x00400001
    -------------------------------------------------------
     0ba20000 01004000 00000000 00000104 l ....@.........
    
     <16 bytes per line>
    
    BBED>

PRINT[/x|d|u|o|c] [ DBA | FILE | FILENAME | BLOCK | OFFSET | symbol | *symbol ]

显示数据块中offset位置/指定位置的信息

  x - hexadecimal
  d - decimal
  u - unsigned decimal
  o - octal
  c - character (native)
  以16进制,10进制,8进制,字符显示
  DBA | FILE | FILENAME | BLOCK | OFFSET可参照以上dump用法
  BBED> p kcvfhbfh.rdba_kcbh
  ub4 rdba_kcbh                               @4        0x00400001
 
  BBED> p *kcvfhbfh.rdba_kcbh
  BBED-00206: out of range offset (4194305)
 
 
  BBED> p *kcvfhtnm
  kcvfh.kcvfhhdr.kccfhtag[0].kccfhtag[19]
  ---------------------------------------
  text kccfhtag[19]                           @83       
 
  BBED> p *kcvfhtnm[1]
  kcvfh.kcvfhhdr.kccfhtag[0].kccfhtag[25]
  ---------------------------------------
  text kccfhtag[25]                           @89       
 
  BBED>   

EXAMINE[/Nuf] [ DBA | FILE | FILENAME | BLOCK | OFFSET | symbol | *symbol ]

用不同进制显示不同单位的数据

</Nuf>:
N - a number which specifies a repeat count.   --命令重复的次数
u - a letter which specifies a unit size:      --指定显示的单位
  b - b1, ub1 (byte)
  h - b2, ub2 (half-word)
  w - b4, ub4(word)
  r - Oracle table/index row
f - a letter which specifies a display format: --指定显示的格式
  x - hexadecimal
  d - decimal
  u - unsigned decimal
  o - octal
  c - character (native)
  n - Oracle number
  t - Oracle date
  i - Oracle rowid
 
  BBED> x/4bc offset 338 --显示在偏移量为338处的4个字符
  pad                                         @338     
  ---
  SYST
 
  BBED> x/6bc offset 338 --显示在偏移量为338处的6个字符
  pad                                         @338     
  ---
  SYSTEM
 
  BBED> 


FIND[/x|d|u|o|c] numeric/character string [ TOP | CURR ]

以指定的格式查找信息

   BBED> f/c SYSTEM
    File: /oradata/ora10/system01.dbf (1)
    Block: 1                Offsets:  338 to  347           Dba:0x00400001
   ------------------------------------------------------------------------
    53595354 454d0000 0000
   
    <32 bytes per line>
   
   BBED>
   BBED> f/c S
    File: /oradata/ora10/system01.dbf (1)
    Block: 1                Offsets:  338 to  347           Dba:0x00400001
   ------------------------------------------------------------------------
    53595354 454d0000 0000
   
    <32 bytes per line>
   
   BBED> f --重复执行上次执行的查找命令
    File: /oradata/ora10/system01.dbf (1)
    Block: 1                Offsets:  340 to  349           Dba:0x00400001
   ------------------------------------------------------------------------
    5354454d 00000000 0000
   
    <32 bytes per line>
   
   BBED>

COPY [ DBA | FILE | FILENAME | BLOCK ] TO [ DBA | FILE | FILENAME | BLOCK ]

复制数据块至另一个数据块。这个命令很管用,如果某个块坏掉,可以从备份的文件中复制一个块

   BBED> copy dba 4,1 to dba 1,1
    File: /oradata/ora10/system01.dbf (1)
    Block: 1                Offsets:   15 to   24           Dba:0x00400001
   ------------------------------------------------------------------------
    0435c700 00000000 0000
   
    <32 bytes per line>
   
   BBED>

 
MODIFY[/x|d|u|o|c] numeric/character string

      [ DBA | FILE | FILENAME | BLOCK | OFFSET | symbol | *symbol ]

以指定的格式修改数据块内容

  BBED> p kcvfhbfh
    struct kcvfhbfh, 20 bytes                   @0       
     ub1 type_kcbh                            @0        0x0b
     ub1 frmt_kcbh                            @1        0xa2
     ub1 spare1_kcbh                          @2        0x00
     ub1 spare2_kcbh                          @3        0x00
     ub4 rdba_kcbh                            @4        0x00400001
     ub4 bas_kcbh                             @8        0x00000000
     ub2 wrp_kcbh                             @12       0x0000
     ub1 seq_kcbh                             @14       0x01
     ub1 flg_kcbh                             @15       0x04 (KCBHFCKV)
     ub2 chkval_kcbh                          @16       0x73a8
     ub2 spare3_kcbh                          @18       0x0000
    
  BBED> d/v offset 0 count 20
   File: /oradata/ora10/system01.dbf (1)
   Block: 1       Offsets:    0 to   19  Dba:0x00400001
  -------------------------------------------------------
   0ba20000 01004000 00000000 00000104 l ....@.........
   a8730000                            l ╯..
 
   <16 bytes per line>
 
  BBED> m/x 02004000 offset 4
   File: /oradata/ora10/system01.dbf (1)
   Block: 1                Offsets:    4 to   23           Dba:0x00400001
  ------------------------------------------------------------------------
   02004000 00000000 00000104 a8730000 00000000
 
   <32 bytes per line>
  BBED> d/v count 10
   File: /oradata/ora10/system01.dbf (1)
   Block: 1       Offsets:    4 to   13  Dba:0x00400001
  -------------------------------------------------------
   02004000 00000000 0000              l ..@.......
 
   <16 bytes per line>
 
  BBED>   
  BBED> p/w
  kcvfh.kcvfhbfh.rdba_kcbh
  ------------------------
  ub4 rdba_kcbh                               @4        0x00400002
 
  BBED>

ASSIGN[/x|d|u|o] <target spec>=<source spec>
<target spec> : [ DBA | FILE | FILENAME | BLOCK | OFFSET | symbol | *symbol ]
<source spec> : [ value | <target spec options> ]

SUM [ DBA | FILE | FILENAME | BLOCK ] [ APPLY ]     

计算块的checksum值,请参考How to calculate checksum(chkval_kcbh)?

  BBED> sum
  Check value for File 1, Block 1:
  current = 0x73a8, required = 0x73ab
 
  BBED> 

PUSH [ DBA | FILE | FILENAME | BLOCK | OFFSET ]

POP [ALL]

Push/Pop用于记录数据块地址,允许当前块暂时被保存,其它块可以被查看或修改。用堆栈保存dba,起到标签的作用

   BBED> set dba 1,4
           DBA             0x00400004 (4194308 1,4)
   
   BBED> m/x 3
    File: /oradata/ora10/system01.dbf (1)
    Block: 4                Offsets:    0 to    9           Dba:0x00400004
   ------------------------------------------------------------------------
    03a20000 04004000 0c00
   
    <32 bytes per line>
   
   BBED> push dba 1,4
           DBA             0x00400004 (4194308 1,4)
           OFFSET          0
   
   BBED> set dba 1,6
           DBA             0x00400006 (4194310 1,6)
   
   BBED> d/v
    File: /oradata/ora10/system01.dbf (1)
    Block: 6       Offsets:    0 to    9  Dba:0x00400006
   -------------------------------------------------------
    1ea20000 06004000 1000              l ....@...
   
    <16 bytes per line>
   
   BBED> pop
           DBA             0x00400004 (4194308 1,4)
           OFFSET          0
   
   BBED> d/v
    File: /oradata/ora10/system01.dbf (1)
    Block: 4       Offsets:    0 to    9  Dba:0x00400004
   -------------------------------------------------------
    03a20000 04004000 0c00              l ....@...
   
    <16 bytes per line>
   
   BBED>
   BBED> pop
           DBA             0x00400004 (4194308 1,4)
           OFFSET          0
   
   BBED> pop
           DBA             0x00400002 (4194306 1,2)
           OFFSET          0
   
   BBED> pop
           DBA             0x00400001 (4194305 1,1)
           OFFSET          0
   
   BBED> pop
   BBED-00211: location stack is empty
   BBED>
 
REVERT [ DBA | FILE | FILENAME | BLOCK ]  

还原dba,file,filename,block到原始状态

   BBED> m /x 3 dba 1,3
    File: /oradata/ora10/system01.dbf (1)
    Block: 3                Offsets:    0 to    9           Dba:0x00400003
   ------------------------------------------------------------------------
    03a20000 03004000 8483
   
    <32 bytes per line>
   
   BBED> m /x 3 dba 1,4
    File: /oradata/ora10/system01.dbf (1)
    Block: 4                Offsets:    0 to    9           Dba:0x00400004
   ------------------------------------------------------------------------
    03a20000 04004000 0c00
   
    <32 bytes per line>
   
   
   BBED> revert
   All changes made in this session will be rolled back. Proceed? (Y/N) y
   Reverted file '/oradata/ora10/system01.dbf', block 3
   Reverted file '/oradata/ora10/system01.dbf', block 4
   Warning: contents of previous BIFILE will be lost. Proceed? (Y/N) y
   
   BBED>
 

UNDO 

撤销更改,再次执行会重做

   BBED> d/v
    File: /oradata/ora10/system01.dbf (1)
    Block: 4       Offsets:    0 to    9  Dba:0x00400004
   -------------------------------------------------------
    03a20000 04004000 0c00              l ....@...
   
    <16 bytes per line>
   
   BBED> undo
   BBED> modify /x 1E filename '/oradata/ora10/system01.dbf' block 4. offset 0.
    File: /oradata/ora10/system01.dbf (1)
    Block: 4                Offsets:    0 to    9           Dba:0x00400004
   ------------------------------------------------------------------------
    1ea20000 04004000 0c00
   
    <32 bytes per line>
   
   
   BBED> undo
   BBED> modify /x 03 filename '/oradata/ora10/system01.dbf' block 4. offset 0.
    File: /oradata/ora10/system01.dbf (1)
    Block: 4                Offsets:    0 to    9           Dba:0x00400004
   ------------------------------------------------------------------------
    03a20000 04004000 0c00
   
    <32 bytes per line>

HELP [ <bbed command> | ALL ]

显示帮助信息

   BBED> help f
   FIND[/x|d|u|o|c] numeric/character string [ TOP | CURR ]
   
   BBED> help m
   MODIFY[/x|d|u|o|c] numeric/character string
         [ DBA | FILE | FILENAME | BLOCK | OFFSET | symbol | *symbol ]
   
   BBED> help p
   PRINT[/x|d|u|o|c] [ DBA | FILE | FILENAME | BLOCK | OFFSET | symbol | *symbol ]
   
   BBED> help x
   EXAMINE[/Nuf] [ DBA | FILE | FILENAME | BLOCK | OFFSET | symbol | *symbol ]
   </Nuf>:
   N - a number which specifies a repeat count.
   u - a letter which specifies a unit size:
     b - b1, ub1 (byte)
     h - b2, ub2 (half-word)
     w - b4, ub4(word)
     r - Oracle table/index row
   f - a letter which specifies a display format:
     x - hexadecimal
     d - decimal
     u - unsigned decimal
     o - octal
     c - character (native)
     n - Oracle number
     t - Oracle date
     i - Oracle rowid
   
   BBED> 


VERIFY [ DBA | FILE | FILENAME | BLOCK ]   

校验块的完整性

修改块后要重新计算chksum值。为了做测试,不应用新的chksum值,这时做校验,就会出现坏块

  BBED> sum 
  Check value for File 1, Block 1:
   current = 0x73a8, required = 0x73ab
   
   BBED> verify
   DBVERIFY - Verification starting
   FILE = /oradata/ora10/system01.dbf
   BLOCK = 1
   
   Block 1 is corrupt
   Corrupt block relative dba: 0x00400001 (file 0, block 1)
   Bad header found during verification
   Data in bad block:
    type: 11 format: 2 rdba: 0x00400002
    last change scn: 0x0000.00000000 seq: 0x1 flg: 0x04
    spare1: 0x0 spare2: 0x0 spare3: 0x0
    consistency value in tail: 0x00000b01
    check value in block header: 0x73a8
    computed block checksum: 0x3
   
   
   DBVERIFY - Verification complete
   
   Total Blocks Examined         : 1
   Total Blocks Processed (Data) : 0
   Total Blocks Failing   (Data) : 0
   Total Blocks Processed (Index): 0
   Total Blocks Failing   (Index): 0
   Total Blocks Empty            : 0
   Total Blocks Marked Corrupt   : 1
   Total Blocks Influx           : 0
   
   BBED> 

CORRUPT [ DBA | FILE | FILENAME | BLOCK ]           

设置块为坏块,更改seq_kcbh(offset 14)为0xff

   BBED> p kcvfhbfh
   struct kcvfhbfh, 20 bytes                   @0       
      ub1 type_kcbh                            @0        0x0b
      ub1 frmt_kcbh                            @1        0xa2
      ub1 spare1_kcbh                          @2        0x00
      ub1 spare2_kcbh                          @3        0x00
      ub4 rdba_kcbh                            @4        0x00400002
      ub4 bas_kcbh                             @8        0x00000000
      ub2 wrp_kcbh                             @12       0x0000
      ub1 seq_kcbh                             @14       0x01
      ub1 flg_kcbh                             @15       0x04 (KCBHFCKV)
      ub2 chkval_kcbh                          @16       0x73a8
      ub2 spare3_kcbh                          @18       0x0000
   
   BBED> corrupt
   Block marked media corrupt.
   
   BBED> p kcvfhbfh
   struct kcvfhbfh, 20 bytes                   @0       
      ub1 type_kcbh                            @0        0x0b
      ub1 frmt_kcbh                            @1        0xa2
      ub1 spare1_kcbh                          @2        0x00
      ub1 spare2_kcbh                          @3        0x00

      ub4 rdba_kcbh                            @4        0x00400001     

      ub4 bas_kcbh                             @8        0x00000000
      ub2 wrp_kcbh                             @12       0x0000
      ub1 seq_kcbh                             @14       0xff
      ub1 flg_kcbh                             @15       0x04 (KCBHFCKV)
      ub2 chkval_kcbh                          @16       0x73a8
      ub2 spare3_kcbh                          @18       0x0000
   
   BBED> 


Reference

http://orafaq.com/papers/dissassembling_the_data_block.pdf

Understanding Datafile Header kcvfh structure


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