使用BBED理解和修改Oracle数据块
1.生成bbed list file文件:
SQL> select file#||' '||name||' '||bytes from v$datafile;
$ vim dbfile.txt
1 /u01/app/oradata/sydb/system01.dbf 754974720
2 /u01/app/oradata/sydb/sysaux01.dbf 587202560
3 /u01/app/oradata/sydb/undotbs01.dbf 429916160
4 /u01/app/oradata/sydb/users01.dbf 13107200
5 /disk2/oradata/sydb/tbs01.dbf 1816133632
6 /disk2/oradata/sydb/tbs02.dbf 119537664
7 /disk2/oradata/sydb/tbs03.dbf 20971520
8 /tmp/tbs_tmp.dbf 10485760
2.生成bbed参数文件:
$ vim bbed.par
mode=edit
listfile= dbfile.txt
blocksize=8192
3.创建测试表和数据:
create table tt1 (id number,name varchar2(30)) tablespace tbs03;
insert into tt1 values(1,'AAAA');
insert into tt1 values(2,'BBBB');
commit;
4.查询表数据行所在的数据块号:
select
dbms_rowid.rowid_block_number(rowid) blocknum,
dbms_rowid.ROWID_RELATIVE_FNO(rowid) fileNo,
id,name
from tt1;
BLOCKNUM FILENO ID NAME
---------- ---------- ---------- ------------------------------
135 7 1 AAAA
135 7 2 BBBB
5.使用bbed:
$ bbed parfile=bbed.par
Password: ==>blockedit is default password of bbed
BBED: Release 2.0.0.0.0 - Limited Production on Tue Mar 31 20:39:29 2015
Copyright (c) 1982, 2009, Oracle and/or its affiliates. All rights reserved.
************* !!! For Oracle Internal Use only !!! ***************
BBED> set filename '/disk2/oradata/sydb/tbs03.dbf' block 135
FILENAME /disk2/oradata/sydb/tbs03.dbf
BLOCK# 135
BBED> map
File: /disk2/oradata/sydb/tbs03.dbf (0)
Block: 135 Dba:0x00000000
------------------------------------------------------------
KTB Data Block (Table/Cluster)
struct kcbh, 20 bytes @0 =>数据块头
struct ktbbh, 72 bytes @20 =>事物层
struct kdbh, 14 bytes @100 =>数据层
struct kdbt[], 4 bytes @114 ==>表目录层
sb2 kdbr[] @118 ==>行目录层
ub1 freespace[] @122 ==>空闲空间
ub1 rowdata[] @8166 ==>实际行数据
ub4 tailchk @8188 ==>校验码
使用print打印数据块结构信息PRINT[/x|d|u|o|c] [ DBA | FILE | FILENAME | BLOCK | OFFSET | symbol | *symbol ]
BBED> print kcbh
struct kcbh, 20 bytes @0
ub1 type_kcbh @0 0x06 ==>块类型(参考下图:Block Type)
ub1 frmt_kcbh @1 0xa2 ==>块格式
ub1 spare1_kcbh @2 0x00 ==>保留空间
ub1 spare2_kcbh @3 0x00 ==>保留空间
ub4 rdba_kcbh @4 0x01c00087 ==>块地址
ub4 bas_kcbh @8 0x002fa91a ==>base SCN
ub2 wrp_kcbh @12 0x0000 ==>wrap SCN
ub1 seq_kcbh @14 0x01 ==>SCN 序列
ub1 flg_kcbh @15 0x06 (KCBHFDLC, KCBHFCKV) ==> 块属性(0x01 新块,0x02我的理解是延迟修改的块,0x04检查保存的块,0x08 Temporary block)
ub2 chkval_kcbh @16 0xe534 ==>校验码,它的值取决于参数(db_block_checksum)的设置值
ub2 spare3_kcbh @18 0x0000 ==>保留空间
-
BlockTypeNumber
BlockType
01
Undo segment header
02
Undo data block
03
Save undo header
04
Save undo data block
05
Data segment header
06
Trans data,KTB manager data block (with ITL)
07
Temp table data block (no ITL)
08
Sort key
09
Sort run
10
Segment free list block
11
Data file header
(图:Block Type)
打印具体结构值:
BBED> print type_kcbh
ub1 type_kcbh @0 0x06
BBED> print frmt_kcbh
ub1 frmt_kcbh @1 0xa2
事务层:
BBED> print ktbbh
struct ktbbh, 72 bytes @20
ub1 ktbbhtyp @20 0x01 (KDDBTDATA) ==>块类型,01 Data,02 Index
union ktbbhsid, 4 bytes @24 ==>对象号(DBA_OBJECTS.OBJECT_ID)/段号
ub4 ktbbhsg1 @24 0x0001a2c4 ==>对象段号
ub4 ktbbhod1 @24 0x0001a2c4 ==>对象号
struct ktbbhcsc, 8 bytes @28
ub4 kscnbas @28 0x002fbaab ==>SCN Base
ub2 kscnwrp @32 0x0000 ==>SCN Wrap
sb2 ktbbhict @36 2 ==>事务槽号(ITL number)
ub1 ktbbhflg @38 0x32 (NONE) ==>on the free list
ub1 ktbbhfsl @39 0x00 ==>ITL TX free list slot
ub4 ktbbhfnx @40 0x01c00080 ==>下一个空闲块的地址 (next free block dba)
struct ktbbhitl[], 24 bytes @44 ==>事务槽1
struct ktbitxid, 8 bytes @44 ==>xid V$TRANSACTION.XID
ub2 kxidusn @44 0x0005 ==>usn V$TRANSACTION.XIDUSN
ub2 kxidslt @46 0x001f ==>slot V$TRANSACTION.XIDSLOT
ub4 kxidsqn @48 0x000009cb ==>sqn V$TRANSACTION.UBASQN
struct ktbituba, 8 bytes @52 ==>uba
ub4 kubadba @52 0x00c002d1 ==>dba
ub2 kubaseq @56 0x0375 ==>seq
ub1 kubarec @58 0x11 ==>V$TRANSACTION.UBAREC
ub2 ktbitflg @60 0xa000 (KTBFUPB, KTBFCOM)
union _ktbitun, 2 bytes @62
sb2 _ktbitfsc @62 0
ub2 _ktbitwrp @62 0x0000
ub4 ktbitbas @64 0x002fb364
struct ktbbhitl[], 24 bytes @68 ==>事务槽2
struct ktbitxid, 8 bytes @68
ub2 kxidusn @68 0x0000
ub2 kxidslt @70 0x0000
ub4 kxidsqn @72 0x00000000
struct ktbituba, 8 bytes @76
ub4 kubadba @76 0x00000000
ub2 kubaseq @80 0x0000
ub1 kubarec @82 0x00
ub2 ktbitflg @84 0x0000 (NONE)
union _ktbitun, 2 bytes @86
sb2 _ktbitfsc @86 0
ub2 _ktbitwrp @86 0x0000
ub4 ktbitbas @88 0x00000000
数据层:
BBED> print kdbh
struct kdbh, 14 bytes @100
ub1 kdbhflag @100 0x00 (NONE) ==>标记(N=ptcfree hit(clusters),F=do not put on free list,K=flushable cluster keys)
sb1 kdbhntab @101 1 ==>表个数
sb2 kdbhnrow @102 2 ==>块包含的行数
sb2 kdbhfrre @104 -1 ==>是否在空闲列表 -1不在空闲列表
sb2 kdbhfsbo @106 22 ==>空闲空间的开始补偿
sb2 kdbhfseo @108 8066 ==>空闲空间的结束补偿
sb2 kdbhavsp @110 8044 ==>块的平均空间
sb2 kdbhtosp @112 8044 ==>块可以使用的总空间
校验码:
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:
BBED> find /x 41414141
File: /disk2/oradata/sydb/tbs03.dbf (0)
Block: 135 Offsets: 8184 to 8191 Dba:0x00000000
------------------------------------------------------------------------
41414141 01061aa9
修改值(mode 必须为edit):
MODIFY[/x|d|u|o|c] numeric/character string
通过已知的文件号7,block 135,offset把AAAA的值修改为ABCE
BBED> modify /c ABCE file 7 block 135 offset 8184
Warning: contents of previous BIFILE will be lost. Proceed? (Y/N) Y
File: /disk2/oradata/sydb/tbs03.dbf (7)
Block: 135 Offsets: 8184 to 8191 Dba:0x01c00087
------------------------------------------------------------------------
41424345 0106abba
提交修改:
SUM [ DBA | FILE | FILENAME | BLOCK ] [ APPLY ]
BBED> sum apply
Check value for File 7, Block 135:
current = 0xbe37, required = 0xbe37
验证数据块:
VERIFY [ DBA | FILE | FILENAME | BLOCK ]
BBED> verify
DBVERIFY - Verification starting
FILE = /disk2/oradata/sydb/tbs03.dbf
BLOCK = 135
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
验证数据的修改,注:应该在数据库关闭时使用bbed修改数据块,因为当数据库运行时,数据块可能被修改覆盖,这里只是做为测试,并没有其它任何dml或其它操作,当bbed修改数据块并物理保存后,在内存中的数据块并没有刷新,所以此时查询到的数据依然是旧数据:
SQL> column dump format a60
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
清理buffer_cache和share_pool 触发物理读,数据正确:
SQL>alter system flush buffer_cache;
System altered.
Elapsed: 00:00:00.93
SQL>alter system flush shared_pool;
System altered.
SQL> select name,dump(name,16)dump from tt1;
NAME DUMP
------------------------------ ------------------------------------------------------------
ABCE Typ=1 Len=4: 41,42,43,45
BBBB Typ=1 Len=4: 42,42,42,42
撤销操作:
REVERT [ DBA | FILE | FILENAME | BLOCK ]
撤销当前会话所有操作:
BBED> revert
All changes made in this session will be rolled back. Proceed? (Y/N) y
Reverted file '/disk2/oradata/sydb/tbs03.dbf', block 135
Warning: contents of previous BIFILE will be lost. Proceed? (Y/N) y
选择文件和数据块撤销:
BBED> revert dba 7,135
撤销当前会话上一个操作:
UNDO
当前值:
SQL> select name,dump(name,16)dump from tt1;
NAME DUMP
------------------------------ ----------------------------------------
DFCA Typ=1 Len=4: 44,46,43,41
BBBB Typ=1 Len=4: 42,42,42,42
BBED> modify /c ibmc dba 7,135 offset 8184
File: /disk2/oradata/sydb/tbs03.dbf (7)
Block: 135 Offsets: 8184 to 8191 Dba:0x01c00087
------------------------------------------------------------------------
69626d63 0106abba
BBED> sum apply
Check value for File 7, Block 135:
current = 0xa93a, required = 0xa93a
确认值:
SQL> alter system flush shared_pool;
SQL> alter system flush buffer_cache;
SQL> select name,dump(name,16)dump from tt1;
NAME DUMP
------------------------------ ----------------------------------------
ibmc Typ=1 Len=4: 69,62,6d,63
BBBB Typ=1 Len=4: 42,42,42,42
UNDO操作:
BBED> undo
BBED> modify /x 44464341 filename '/disk2/oradata/sydb/tbs03.dbf' block 135. offset 8184.
File: /disk2/oradata/sydb/tbs03.dbf (0)
Block: 135 Offsets: 8184 to 8191 Dba:0x00000000
------------------------------------------------------------------------
44464341 0106abba
<32 bytes per line>
BBED> sum apply
Check value for File 0, Block 135:
current = 0xaf39, required = 0xaf39
--The end
使用BBED理解和修改Oracle数据块的更多相关文章
- [转]Oracle数据块体系的详细介绍
数据块概述Oracle对数据库数据文件(datafile)中的存储空间进行管理的单位是数据块(data block).数据块是数据库中最小的(逻辑)数据单位.与数据块对应的,所有数据在操作系统级的最小 ...
- Oracle数据块损坏的恢复实例
测试环境:11.2.0.4 1.构建数据块损坏的测试环境 2.有备份:常规恢复坏块 3.无备份:跳过坏块 1.构建数据块损坏的测试环境 1.1 创建测试表 --Create Table t_test ...
- oracle数据块核心剖析
详见: http://blog.yemou.net/article/query/info/tytfjhfascvhzxcytp57 数据块(Oracle Data Blocks),本文简称为" ...
- java.sql.SQLException: ORA-01578: ORACLE 数据块损坏问题解决办法
错误信息: java.sql.SQLException: ORA-01578: ORACLE 数据块损坏 (文件号 17, 块号 315703) ORA-01110: 数据文件 17: 'D:\ORA ...
- Oracle数据块损坏篇之10231内部事件
实验:某个分区数据块损坏,不完全恢复此分区表数据 背景:数据库没有有效备份,某个分区中有数据块损坏. 要求:最大限度恢复此分区数据. 环境:RHEL 6.4 + Oracle 11.2.0.4 1. ...
- Oracle数据块深入分析总结
http: 最近在研究块的内部结构,把文档简单整理了一下,和大家分享一下.该篇文章借助dump和BBED对数据 库内部结构进行了分析,最后附加了一个用BBED解决ORA-1200错误的小例子.在总结的 ...
- Oracle 数据块
以emp表为例 SYS@ prod>select * from scott.emp; EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO --------- ...
- ORA-01578: ORACLE 数据块损坏 (文件号 10, 块号 57896)ORA-01110: 数据文件 10: '/data/oradata/prod35.dbf'
https://community.oracle.com/thread/3540795 概述 ------------- 数据库坏块(corruption) 的类型可以按照坏块所属对象的不同,分为用户 ...
- ORACLE 数据块dump
1. rdba(Tablespace relative database block address) 是相对数据块地址,是数据所在的地址,rdba可就是rowid 中rfile#+block#. 根 ...
随机推荐
- h264 aac 封装 flv
Part 1flvtag组成 FLV 文件结构由 FLVheader和FLVBody组成.(注意flv文件是大端格式的)FLV头组成(以c为例子,一字节对齐):FLVBody是由若干个Tag组成的: ...
- SpringMVC之八：基于SpringMVC拦截器和注解实现controller中访问权限控制
SpringMVC的拦截器HandlerInterceptorAdapter对应提供了三个preHandle,postHandle,afterCompletion方法. preHandle在业务处理器 ...
- 常见的sql server 链接问题------持续更新
问题1:超时时间已到.超时时间已到,但是尚未从池中获取连接.出现这种情况可能是因为所有池连接均在使用,并且达到了最大池大小 再查询窗口输入exec sp_who2进行查询链接消耗资源 可能出现的情况是 ...
- cinder backup ceph的配置和使用
Backup 是将 volume 备份到别的地方(备份设备),将来可以通过 restore 操作恢复. 初看 backup 功能好像与 snapshot 很相似,都可以保存 volume 的当前状态, ...
- IE6中PNG图片背景无法透明显示的最佳解决方案
我想,对于像我这样的年轻的程序员来说,做网页开发时用chrome.firefox或者ie10什么的大约是被宠坏了.所以当最近做的项目不得不在恐龙化石般的ie6上运行时,ie6种种诡异的行径简直让我发指 ...
- java面向对象基础复习
对java基础的一个复习总结吧. 1.继承:通过使用关键字extends,子类可以继承父类所有的方法和属性,但是无法使用 private(私有) 的方法和属性,一次只能继承一个父类. 2.重写:重写( ...
- C# HTTP请求GET，POST
转自原文 [C#]HTTP请求GET,POST HTTP定义了与服务器交互的不同方法,基本方法有GET,POST,PUT,DELETE,分别对于查,该,增,删.一般情况下我们只用到GET和POST,其 ...
- C#获取外网IP、本机MAC地址及Ping的实现
原文 获取外网IP, C#获取本机的MAC地址,C#通过编程方式实现Ping 获取外网IP地址 思路是通过WebRequest连接一些网上提供IP查询服务的网站,下载到含有你的IP的网页,然后用正则表 ...
- [转] C#调用外部DLL
原文地址 每种编程语言调用DLL的方法都不尽相同,在此只对用C#调用DLL的方法进行介绍.首先,您需要了解什么是托管,什么是非托管.一般可以认为:非托管代码主要是基于win 32平台开发的DLL,ac ...
- Delphi 拖动
interface uses Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs; type TForm1 ...