table中各种类型block坏块是否能被跳过

联系:手机(+86 13429648788) QQ(107644445)QQ咨询惜分飞

标题:table中各种类型block坏块是否能被跳过

作者:惜分飞©版权所有[未经本人同意,不得以任何形式转载,否则有进一步追究法律责任的权利.]

在table遇到的各种坏块中,大部分情况,我们都可以通过设置event 10231或者dbms_repair来跳过坏块,抢救其他数据;但是在部分情况下,我们设置了他们依然不能跳过坏块,数据库依然报ORA-01578,本文测试了table中各种类型的block,证明在哪些blog出现异常之后不能被跳过.
如果是事务数据块出现坏块可以通过dbms_repair.skip_corrupt_blocks来标记坏块(也可以使用event 10231)来实现;对于BITMAP BLOCK如果出现坏块不会对于读取数据无影响(至于其他操作,请见后续blog);SEGMENT HEADER如果出现坏块,无法通过跳过坏块来实现获取其他数据(正常block)
创建测试表

SQL> select * from v$version;

BANNER
--------------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - Production
PL/SQL Release 11.2.0.3.0 - Production
CORE    11.2.0.3.0      Production
TNS for Linux: Version 11.2.0.3.0 - Production
NLSRTL Version 11.2.0.3.0 - Production

SQL> create table t_xifenfei 
  2  tablespace users 
  3  as
  4  select * from dba_objects;

Table created.

SQL>  select count(*) from chf.t_xifenfei;

  COUNT(*)
----------
     74663

查询相关block信息

SQL> select SEGMENT_NAME,HEADER_FILE,HEADER_BLOCK,blocks,extents from DBA_SEGMENTS 
  2  WHERE OWNER='CHF' AND SEGMENT_NAME='T_XIFENFEI';

SEGMENT_NAME    HEADER_FILE HEADER_BLOCK     BLOCKS    EXTENTS
--------------- ----------- ------------ ---------- ----------
T_XIFENFEI                4          378       1152         24

SQL>   select   
  2    dbms_rowid.rowid_relative_fno(rowid)rel_fno,
  3    max(dbms_rowid.rowid_block_number(rowid)) max_block,
  4    min(dbms_rowid.rowid_block_number(rowid)) min_block
  5    from chf.t_xifenfei 
  6    group by dbms_rowid.rowid_relative_fno(rowid);

   REL_FNO  MAX_BLOCK  MIN_BLOCK
---------- ---------- ----------
         4       1728        379

SQL> select EXTENT_ID,FILE_ID,BLOCK_ID,blocks from dba_extents where owner='CHF'
   2  AND SEGMENT_NAME='T_XIFENFEI';

 EXTENT_ID    FILE_ID   BLOCK_ID     BLOCKS
---------- ---------- ---------- ----------
         0          4        376          8
         1          4        640          8
         2          4        648          8
         3          4        656          8
         4          4        664          8
         5          4        672          8
         6          4        680          8
         7          4        688          8
         8          4        696          8
         9          4        704          8
        10          4        712          8
        11          4        720          8
        12          4        728          8
        13          4        736          8
        14          4        744          8
        15          4        752          8
        16          4        768        128
        17          4        896        128
        18          4       1024        128
        19          4       1152        128
        20          4       1280        128
        21          4       1408        128
        22          4       1536        128
        23          4       1664        128

通过这里可以知道:真正的存储数据是从block 379开始,至于block 376、377、378是什么,使用dump block分析

验证block类型

SQL> alter system dump datafile 4 block 376;

System altered.

SQL> alter system dump datafile 4 block 377;

System altered.

SQL> alter system dump datafile 4 block 378;

System altered.

SQL> alter system dump datafile 4 block 379;

System altered.

--该block是另外extent的开始,所以也尝试分析是否有特殊之处
SQL> alter system dump datafile 4 block 640;

System altered.

--dump 文件header信息
Start dump data blocks tsn: 4 file#:4 minblk 376 maxblk 376
Block dump from cache:
Dump of buffer cache at level 4 for tsn=4 rdba=16777592
Block dump from disk:
buffer tsn: 4 rdba: 0x01000178 (4/376)
scn: 0x0b8c.3bfc6517 seq: 0x04 flg: 0x04 tail: 0x65172004
frmt: 0x02 chkval: 0xc8b3 type: 0x20=FIRST LEVEL BITMAP BLOCK


Start dump data blocks tsn: 4 file#:4 minblk 377 maxblk 377
Block dump from cache:
Dump of buffer cache at level 4 for tsn=4 rdba=16777593
Block dump from disk:
buffer tsn: 4 rdba: 0x01000179 (4/377)
scn: 0x0b8c.3bfc6517 seq: 0x18 flg: 0x04 tail: 0x65172118
frmt: 0x02 chkval: 0x9e8c type: 0x21=SECOND LEVEL BITMAP BLOCK


Start dump data blocks tsn: 4 file#:4 minblk 378 maxblk 378
Block dump from cache:
Dump of buffer cache at level 4 for tsn=4 rdba=16777594
BH (0x2a7f7f0c) file#: 4 rdba: 0x0100017a (4/378) class: 4 ba: 0x2a742000
  set: 5 pool: 3 bsz: 8192 bsi: 0 sflg: 1 pwc: 0,0
  dbwrid: 0 obj: 76372 objn: 76372 tsn: 4 afn: 4 hint: f
  hash: [0x3150a748,0x3150a748] lru: [0x2a7f8094,0x2a7f7ee4]
  lru-flags: hot_buffer
  ckptq: [NULL] fileq: [NULL] objq: [0x2f72dc34,0x2f72dc34] objaq: [0x2f72dc2c,0x2f72dc2c]
  st: XCURRENT md: NULL fpin: 'ktewh25: kteinicnt' tch: 1
  flags:
  LRBA: [0x0.0.0] LSCN: [0x0.0] HSCN: [0xffff.ffffffff] HSUB: [65535]
Block dump from disk:
buffer tsn: 4 rdba: 0x0100017a (4/378)
scn: 0x0b8c.3bfc651b seq: 0x01 flg: 0x04 tail: 0x651b2301
frmt: 0x02 chkval: 0xb2ae type: 0x23=PAGETABLE SEGMENT HEADER

Start dump data blocks tsn: 4 file#:4 minblk 379 maxblk 379
Block dump from cache:
Dump of buffer cache at level 4 for tsn=4 rdba=16777595
Block dump from disk:
buffer tsn: 4 rdba: 0x0100017b (4/379)
scn: 0x0b8c.3bfc6494 seq: 0x01 flg: 0x04 tail: 0x64940601
frmt: 0x02 chkval: 0x0567 type: 0x06=trans data

Start dump data blocks tsn: 4 file#:4 minblk 640 maxblk 640
Block dump from cache:
Dump of buffer cache at level 4 for tsn=4 rdba=16777856
Block dump from disk:
buffer tsn: 4 rdba: 0x01000280 (4/640)
scn: 0x0b8c.3bfc6496 seq: 0x01 flg: 0x04 tail: 0x64960601
frmt: 0x02 chkval: 0x0efe type: 0x06=trans data

这里可以知道:
1.block 376、377为BITMAP BLOCK
2.block 378为SEGMENT HEADER(和dba_segments视图中一致)
3.除extent 0中有特殊(含BITMAP BLOCK和SEGMENT HEADER)block,其他extent只包含事务数据

测试block 640

--block 640包含条数
SQL> select   count(rowid)
  2    from chf.t_xifenfei 
  3     where dbms_rowid.rowid_block_number(rowid)=640
  4  and dbms_rowid.rowid_relative_fno(rowid)=4;

COUNT(ROWID)
------------
          79

--bbed修改tailchk
BBED> set filename '/u01/oracle/oradata/ora11g/users01.dbf'
        FILENAME        /u01/oracle/oradata/ora11g/users01.dbf

BBED> set block 640
        BLOCK#          640

BBED> set mode edit
        MODE            Edit

BBED> p tailchk
ub4 tailchk                                 @8188     0x64960601

BBED> m /x 64960602
Warning: contents of previous BIFILE will be lost. Proceed? (Y/N) y
 File: /u01/oracle/oradata/ora11g/users01.dbf (0)
 Block: 640              Offsets: 8188 to 8191           Dba:0x00000000
------------------------------------------------------------------------
 64960602 

 <32 bytes per line>

BBED> sum apply
Check value for File 0, Block 640:
current = 0xf80b, required = 0xf80b

BBED> verify
DBVERIFY - Verification starting
FILE = /u01/oracle/oradata/ora11g/users01.dbf
BLOCK = 640

Block 640 is corrupt
Corrupt block relative dba: 0x01000280 (file 0, block 640)
Fractured block found during verification
Data in bad block:
 type: 6 format: 2 rdba: 0x01000280
 last change scn: 0x0b8c.3bfc6496 seq: 0x1 flg: 0x04
 spare1: 0x0 spare2: 0x0 spare3: 0x0
 consistency value in tail: 0x02069664
 check value in block header: 0xf80b
 computed block checksum: 0x0


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           : 2
Message 531 not found;  product=RDBMS; facility=BBED

--查询坏块
SQL> select count(*) from chf.t_xifenfei;
select count(*) from chf.t_xifenfei
                         *
ERROR at line 1:
ORA-01578: ORACLE data block corrupted (file # 4, block # 640)
ORA-01110: data file 4: '/u01/oracle/oradata/ora11g/users01.dbf'

--跳过坏块
SQL> exec dbms_repair.skip_corrupt_blocks('CHF','T_XIFENFEI');

PL/SQL procedure successfully completed.

SQL>  select skip_corrupt from dba_tables where table_name='T_XIFENFEI' AND OWNER='CHF';

SKIP_COR
--------
ENABLED

SQL>  select count(*) from chf.t_xifenfei;

  COUNT(*)
----------
     74584

--修复坏块
BBED> m /x 01069664
Warning: contents of previous BIFILE will be lost. Proceed? (Y/N) y
 File: /u01/oracle/oradata/ora11g/users01.dbf (0)
 Block: 640              Offsets: 8188 to 8191           Dba:0x00000000
------------------------------------------------------------------------
 01069664 

 <32 bytes per line>

BBED> p tailchk
ub4 tailchk                                 @8188     0x64960601

BBED> sum apply
Check value for File 0, Block 640:
current = 0x0efe, required = 0x0efe

BBED> verify
DBVERIFY - Verification starting
FILE = /u01/oracle/oradata/ora11g/users01.dbf
BLOCK = 640


DBVERIFY - Verification complete

Total Blocks Examined         : 1
Total Blocks Processed (Data) : 1
Total Blocks Failing   (Data) : 0
Total Blocks Processed (Index): 0
Total Blocks Failing   (Index): 0
Total Blocks Empty            : 0
Total Blocks Marked Corrupt   : 0
Total Blocks Influx           : 0
Message 531 not found;  product=RDBMS; facility=BBED

--除掉标记表坏块
SQL> BEGIN
  2  DBMS_REPAIR.SKIP_CORRUPT_BLOCKS (
  3  SCHEMA_NAME => 'CHF',
  4  OBJECT_NAME => 'T_XIFENFEI',
  5  OBJECT_TYPE => dbms_repair.table_object,
  6  FLAGS => dbms_repair.NOSKIP_FLAG);
  7  END;
  8  /

PL/SQL procedure successfully completed.

SQL> select skip_corrupt from dba_tables where table_name='T_XIFENFEI' AND OWNER='CHF';

SKIP_COR
--------
DISABLED

--查询表记录正常
SQL>  select count(*) from chf.t_xifenfei;

  COUNT(*)
----------
     74663

在后续的操作中,也是按照类似步骤操作,考虑到篇幅有限,部分过程不再贴出来

测试block 379

SQL>  select count(*) from chf.t_xifenfei;
 select count(*) from chf.t_xifenfei
                          *
ERROR at line 1:
ORA-01578: ORACLE data block corrupted (file # 4, block # 379)
ORA-01110: data file 4: '/u01/oracle/oradata/ora11g/users01.dbf'


SQL> exec dbms_repair.skip_corrupt_blocks('CHF','T_XIFENFEI');

PL/SQL procedure successfully completed.

SQL> select count(*) from chf.t_xifenfei;

  COUNT(*)
----------
     74575

测试block 378

BBED> set block 378
        BLOCK#          378

--segment header 不支持bbed查看结构
BBED> p tailchk
BBED-00400: invalid blocktype (35)

BBED> map
 File: /u01/oracle/oradata/ora11g/users01.dbf (0)
 Block: 378                                   Dba:0x00000000
------------------------------------------------------------
BBED-00400: invalid blocktype (35)


BBED> set offset 8188
        OFFSET          8188

BBED> d
 File: /u01/oracle/oradata/ora11g/users01.dbf (0)
 Block: 378              Offsets: 8188 to 8191           Dba:0x00000000
------------------------------------------------------------------------
 01231b65 

 <32 bytes per line>

BBED> m /x 651b2302
Warning: contents of previous BIFILE will be lost. Proceed? (Y/N) y
 File: /u01/oracle/oradata/ora11g/users01.dbf (0)
 Block: 378              Offsets: 8188 to 8191           Dba:0x00000000
------------------------------------------------------------------------
 651b2302 

 <32 bytes per line>

BBED> sum apply
Check value for File 0, Block 378:
current = 0xedf2, required = 0xedf2

--验证坏块
BBED> verify
DBVERIFY - Verification starting
FILE = /u01/oracle/oradata/ora11g/users01.dbf
BLOCK = 378

Block 378 is corrupt
Corrupt block relative dba: 0x0100017a (file 0, block 378)
Fractured block found during verification
Data in bad block:
 type: 35 format: 2 rdba: 0x0100017a
 last change scn: 0x0b8c.3bfc651b seq: 0x1 flg: 0x04
 spare1: 0x0 spare2: 0x0 spare3: 0x0
 consistency value in tail: 0x02231b65
 check value in block header: 0xedf2
 computed block checksum: 0x0


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           : 2
Message 531 not found;  product=RDBMS; facility=BBED


SQL>  select count(*) from chf.t_xifenfei;
 select count(*) from chf.t_xifenfei
                          *
ERROR at line 1:
ORA-01578: ORACLE data block corrupted (file # 4, block # 378)
ORA-01110: data file 4: '/u01/oracle/oradata/ora11g/users01.dbf'

--标记跳过坏块
SQL> exec dbms_repair.skip_corrupt_blocks('CHF','T_XIFENFEI');

PL/SQL procedure successfully completed.

--查询依然失败
SQL> select count(*) from chf.t_xifenfei;
select count(*) from chf.t_xifenfei
                         *
ERROR at line 1:
ORA-01578: ORACLE data block corrupted (file # 4, block # 378)
ORA-01110: data file 4: '/u01/oracle/oradata/ora11g/users01.dbf'

测试block 377

BBED> m /x 18211766
Warning: contents of previous BIFILE will be lost. Proceed? (Y/N) y
 File: /u01/oracle/oradata/ora11g/users01.dbf (0)
 Block: 377              Offsets: 8188 to 8191           Dba:0x00000000
------------------------------------------------------------------------
 18211766 

 <32 bytes per line>

BBED> sum apply
Check value for File 0, Block 377:
current = 0x9d8c, required = 0x9d8c

--bbed验证为坏块
BBED> verify
DBVERIFY - Verification starting
FILE = /u01/oracle/oradata/ora11g/users01.dbf
BLOCK = 377

Block 377 is corrupt
Corrupt block relative dba: 0x01000179 (file 0, block 377)
Fractured block found during verification
Data in bad block:
 type: 33 format: 2 rdba: 0x01000179
 last change scn: 0x0b8c.3bfc6517 seq: 0x18 flg: 0x04
 spare1: 0x0 spare2: 0x0 spare3: 0x0
 consistency value in tail: 0x66172118
 check value in block header: 0x9d8c
 computed block checksum: 0x0


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           : 2
Message 531 not found;  product=RDBMS; facility=BBED

--dbv验证为坏块
[oracle@xifenfei ~]$ dbv file=/u01/oracle/oradata/ora11g/users01.dbf

DBVERIFY: Release 11.2.0.3.0 - Production on Fri Jan 18 03:32:18 2013

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.

DBVERIFY - Verification starting : FILE = /u01/oracle/oradata/ora11g/users01.dbf
Page 377 is influx - most likely media corrupt
Corrupt block relative dba: 0x01000179 (file 4, block 377)
Fractured block found during dbv: 
Data in bad block:
 type: 33 format: 2 rdba: 0x01000179
 last change scn: 0x0b8c.3bfc6517 seq: 0x18 flg: 0x04
 spare1: 0x0 spare2: 0x0 spare3: 0x0
 consistency value in tail: 0x66172118
 check value in block header: 0x9d8c
 computed block checksum: 0x0



DBVERIFY - Verification complete

Total Pages Examined         : 2560
Total Pages Processed (Data) : 1434
Total Pages Failing   (Data) : 0
Total Pages Processed (Index): 10
Total Pages Failing   (Index): 0
Total Pages Processed (Other): 213
Total Pages Processed (Seg)  : 0
Total Pages Failing   (Seg)  : 0
Total Pages Empty            : 902
Total Pages Marked Corrupt   : 1
Total Pages Influx           : 1
Total Pages Encrypted        : 0
Highest block SCN            : 1006486374 (2956.1006486374)

--查询表记录
SQL> select skip_corrupt from dba_tables where table_name='T_XIFENFEI' AND OWNER='CHF';

SKIP_COR
--------
DISABLED

SQL> select count(*) from chf.t_xifenfei;

  COUNT(*)
----------
     74663

测试block 376

BBED> m /x 04201766
 File: /u01/oracle/oradata/ora11g/users01.dbf (0)
 Block: 376              Offsets: 8188 to 8191           Dba:0x00000000
------------------------------------------------------------------------
 04201766 

 <32 bytes per line>

BBED> sum apply
Check value for File 0, Block 376:
current = 0xcbb3, required = 0xcbb3

BBED> verify
DBVERIFY - Verification starting
FILE = /u01/oracle/oradata/ora11g/users01.dbf
BLOCK = 376

Block 376 is corrupt
Corrupt block relative dba: 0x01000178 (file 0, block 376)
Fractured block found during verification
Data in bad block:
 type: 32 format: 2 rdba: 0x01000178
 last change scn: 0x0b8c.3bfc6517 seq: 0x4 flg: 0x04
 spare1: 0x0 spare2: 0x0 spare3: 0x0
 consistency value in tail: 0x66172004
 check value in block header: 0xcbb3
 computed block checksum: 0x0


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           : 2
Message 531 not found;  product=RDBMS; facility=BBED

SQL>  select count(*) from chf.t_xifenfei;

  COUNT(*)
----------
     74663

通过测试证明,如果是事务数据块出现坏块可以通过dbms_repair.skip_corrupt_blocks来标记坏块(也可以使用event 10231)来实现;对于BITMAP BLOCK如果出现坏块不会对于读取数据无影响(至于其他操作,请见table中各种坏块对select/dml操作影响);SEGMENT HEADER如果出现坏块,无法通过跳过坏块来实现获取其他数据(正常block)

此条目发表在 Oracle备份恢复 分类目录,贴了 标签。将固定链接加入收藏夹。

发表评论

电子邮件地址不会被公开。 必填项已用 * 标注

您可以使用这些 HTML 标签和属性: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>