前一篇写了asm里dd出文件，这篇里只dd出块，主要是针对文件大的情况。
以scott模式为例：
修改前的表信息
SQL>select * from emp where mgr=7566 and empno=7788
7788 SCOTT ANALYST 7566 1987/4/19 3000.00 201 AU计算：
SQL> selectextent_Id,block_id,blocks,file_id
2 fromdba_extents where segment_name='EMP'
SQL> /
EXTENT_ID BLOCK_ID BLOCKS FILE_ID
-------------------- ---------- ----------
0 144 8 5SQL> selectname from v$datafile where file#=5;
NAME
--------------------------------------------------------------
+DATA/db/datafile/users.276.899048797
SQL> selectname,group_number,file_number from v$asm_alias where name like '%USERS%' andfile_number=276;
NAME GROUP_NUMBER FILE_NUMBER
---------------------------------------------------------------------------------- -----------
USERS.276.899048797 1 276
SQL> selectdisk_kffxp,au_kffxp,xnum_kffxp from x$kffxp where group_kffxp=1 andnumber_kffxp=276;
DISK_KFFXP AU_KFFXP XNUM_KFFXP
---------- ---------- ----------
1 426 0
0 289 1这里计算一下，其block_id为144,块大小为8KB,那么其位置为144*8/1024=1.125M,加上块头8*8/1024=0.0625M,一共不超过4M;应当在第一个AU上（AU大小为4M），第二块盘的第426个AU上，取第二个盘路径：
SQL> selectdisk_number,path from v$asm_disk where disk_number=1;
DISK_NUMBERPATH
-------------------------------------------------------------------------------------------
1 /dev/raw/raw2取出该表的最大和最小data_object_id,然后dd.
SQL> select dbms_rowid.rowid_relative_fno(rowid)rel_fno,
max(dbms_rowid.rowid_block_number(rowid))max_block,
min(dbms_rowid.rowid_block_number(rowid))min_block
from emp
group by dbms_rowid.rowid_relative_fno(rowid);
REL_FNO MAX_BLOCK MIN_BLOCK
-------------------- ----------
5 149 149
[oracle@mysql-1]$ddif=/dev/raw/raw2 bs=1024 count=8 skip=1746088 of=emp.dd说明一下：skip=426*4*1024+149*8
检查一下：
[oracle@mysql-1~]$ strings emp.dd
MILLER
CLERK
FORD
ANALYST
JAMES
CLERK
ADAMS
CLERK
TURNER
SALESMAN
KING PRESIDENT
SCOTT
ANALYST
SMITH
CLERK从上可以看出，是emp的内容。
2 bbed修改内容
11g里首先要安装bbed,安装过程记录一下：
copy oracle 10g的sbbdpt.o,ssbbded.o到$ORACLE_HOME/rdbms/lib下
copybbedus.msb 到$ORACLE_HOME/mesg下
cd$ORACLE_HOME/rdbms/lib
make -fins_rdbms.mk $ORACLE_HOME/rdbms/lib/bbed
cp bbed$ORACLE_HOME/bin[oracle@mysql-1~]$ bbed
BBED> set filename'/home/oracle/emp.dd';
FILENAME /home/oracle/emp.dd#用bbed校验下块。
BBED> verify
DBVERIFY - Verification starting
FILE = /home/oracle/emp.dd
BLOCK = 0
Block 0 is corrupt
Corrupt block relative dba: 0x01400000(file 0, block 0)
Bad header found during verification
Data in bad block:
type: 6 format: 2 rdba: 0x01400095
lastchange scn: 0x0000.0004dec0 seq: 0x1 flg: 0x06
spare1: 0x0 spare2: 0x0 spare3: 0x0
consistency value in tail: 0x00000000
check value in block header: 0x89af
computed block checksum: 0xd6b
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
Message 531 not found; product=RDBMS; facility=BBED用bbed查看dd出文件内容
BBED> set blocksize 8192
BLOCKSIZE 8192
BBED> p kdbr
BBED> find /c SCOTT
File: /home/oracle/emp.dd (0)
Block: 1 Offsets: 7864 to 8191 Dba:0x00000000
------------------------------------------------------------------------
53434f54 5407414e 414c5953 5403c24c 430777bb04130101 0102c21f ff02c115
BBED> dump /v
File: /home/oracle/emp.dd (0)
Block: 1 Offsets: 7864 to 8191 Dba:0x00000000
-------------------------------------------------------
53434f54 5407414e 414c5953 5403c24c lSCOTT.ANALYST..L
430777bb 04130101 0102c21f ff02c115 lC.w.............
2c010803 c24e5305 434c4152 4b074d41 l,....NS.CLARK.MA
4e414745 5203c24f 280777b5 06090101 lNAGER..O(.w.....
0103c219 33ff02c1 0b2c0108 03c24d63 l....3....,....Mc用bbed修改：
set mode edit
set blocksize 8192
find /c SCOTT
m /c SNOWH
BBED> dump /v
File: /home/oracle/emp.dd (0)
Block: 1 Offsets: 7864 to 8191 Dba:0x00000000
-------------------------------------------------------
534e4f57 4807414e 414c5953 5403c24c lSNOWH.ANALYST..L
BBED> sum
Check value for File 0, Block 1:
current = 0x89af, required = 0x87b3
BBED> sum apply
Check value for File 0, Block 1:
current = 0x87b3, required = 0x87b3关库，导入修改后数据：
[oracle@mysql-1~]$ srvctl stop database -d db
[oracle@mysql-1~]$dd of=/dev/raw/raw2 bs=1024 count=8 seek=1746088 if=emp.dd
8+0 records in
8+0 records out
8192 bytes (8.2 kB) copied, 0.00208818 s,3.9 MB/s查询表信息：
[oracle@mysql-1~]$ srvctl start database -d dbSQL> select* from emp where mgr=7566 and empno=7788 2 ;
EMPNOENAME JOB MGR HIREDATE SAL COMM DEPTNO
--------------- --------- ----- ----------- --------- --------- ------
7788 SNOWH ANALYST 7566 1987/4/19 3000.00 20OVER
