使用BBED理解和修改Oracle数据块(4)

BBED> print tailchk
ub4 tailchk        @8188    0xbaab0601  --尾部校验码
tailchk=(低位2个字节)bas_kcbh(0x002fbaab)+(1位字节)type_kcbh(0x06)+(1位字节)seq_kcbh(0x01)  ==>值在块头记录)

查找:
数据表存储的值:

SQL>column name format a8
SQL>column dump format a40
SQL>select name,dump(name,16)dump from tt1;
NAME    DUMP
-------- ----------------------------------------
AAAA    Typ=1 Len=4: 41,41,41,41
BBBB    Typ=1 Len=4: 42,42,42,42

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

Find Switch

 

DataType

 

x

 

Haxadecimal

 

d

 

Decimal

 

u

 

Unsigned decimal

 

o

 

Octal

 

c

 

Character

 

/c 表示通过字符查找:

BBED> find /c AAAA
 File: /disk2/oradata/sydb/tbs03.dbf (0)
 Block: 135              Offsets: 8184 to 8191    Dba:0x00000000
------------------------------------------------------------------------
 41414141 01061aa9

datafile为7,block 135,offset 为8184就是存储AAAA的位置

BBED> dump /v dba 7,135 offset 8184
 File: /disk2/oradata/sydb/tbs03.dbf (7)
 Block: 135    Offsets: 8184 to 8191  Dba:0x01c00087
-------------------------------------------------------
 41414141 0106abba                  l AAAA..

/x 表示使用十六进制查找:

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