【BBED】bbed經常使用命令

時間 2019-12-05

標籤 BBED bbed 經常使用命令简体版

原文原文鏈接

【BBED】bbed經常使用命令html

一.1 相關知識點掃盲

BBED(Oracle Block Browerand EDitor Tool)，用來直接查看和修改數據文件數據的一個工具，是Oracle一款內部工具，能夠直接修改Oracle數據文件塊的內容，在一些極端恢復場景下比較有用。該工具不受Oracle支持，因此默認是沒有生成可執行文件的，在使用前須要從新鏈接。sql

一.1.1 個人編譯代碼

ls -l $ORACLE_HOME/rdbms/lib/*sbbd*數據庫

ls -l $ORACLE_HOME/rdbms/mesg/bbed*windows

chown oracle:dba /u01/app/oracle/product/11.2.0/dbhome_1/rdbms/lib/*sbbd*微信

chown oracle:dba /u01/app/oracle/product/11.2.0/dbhome_1/rdbms/mesg/bbed*session

--cd $ORACLE_HOME/rdbms/lib架構

--make -f ins_rdbms.mk $ORACLE_HOME/rdbms/lib/bbedoracle

--make -f $ORACLE_HOME/rdbms/lib/ins_rdbms.mk $ORACLE_HOME/rdbms/lib/bbedapp

make -f $ORACLE_HOME/rdbms/lib/ins_rdbms.mk BBED=$ORACLE_HOME/bin/bbed $ORACLE_HOME/bin/bbedide

一.1.2 個人使用代碼

vi /home/oracle/file.txt

set line 9999 pagesize 9999

col name format a80

select file#||' '||name||' '||bytes name from v$datafile;

vi /home/oracle/bbed.par

blocksize=8192

listfile=/home/oracle/file.txt

mode=edit

bbed parfile=/home/oracle/bbed.par

bbed PASSWORD=blockedit mode=edit blocksize=8192 listfile=/home/oracle/file.txt

一.1.3 注意事項

① 若使用bbed的過程當中，數據庫有重啓的過程，最好是退出BBED從新進入bbed的環境

② windows下BBED軟件和其餘系統下BBED不太同樣，操做的時候塊號比其餘系統下多一個

一.2 bbed日誌記錄 log.bbd

bbed啓動和運行的過程會將運行過的全部命令記錄到當前的目錄下log.bbd文件中，因此bbed要求oracle用戶在當前目錄具備建立文件的權限。

一.3 報錯

一.3.1 BBED-00303: unable to open file 'log.bbd'

oracle用戶須要對當前操做目錄有權限，不然報錯：

[ZFZHLHRDB2:oracle]:/oracle>bbed

BBED-00303: unable to open file 'log.bbd'

[ZFZHLHRDB2:oracle]:/oracle>touch log.bbd

touch: 0652-046 Cannot create log.bbd.

[ZFZHLHRDB2:oracle]:/oracle>ls -ld

drwxr-xr-x 5 root dba 256 Mar 14 15:41 .

[ZFZHLHRDB2:oracle]:/oracle>cd /home/oracle

[ZFZHLHRDB2:oracle]:/home/oracle>ls -ld

drwxr-xr-x 3 oracle dba 256 Apr 05 17:01 .

[ZFZHLHRDB2:oracle]:/home/oracle>bbed

Password:

BBED-00113: Invalid password. Please rerun utility with the correct password.

[ZFZHLHRDB2:oracle]:/home/oracle>bbed parfile=/home/oracle/bbed.par

Password:

BBED: Release 2.0.0.0.0 - Limited Production on Tue Apr 5 17:28:35 2016

************* !!! For Oracle Internal Use only !!! ***************

BBED> info

File# Name Size(blks)

----- ---- ----------

1 /oracle/app/oracle/oralhr/system01.dbf 96000

2 /oracle/app/oracle/oralhr/sysaux01.dbf 62720

3 /oracle/app/oracle/oralhr/undotbs01.dbf 11520

4 /oracle/app/oracle/oralhr/users01.dbf 640

5 /oracle/app/oracle/oralhr/example01.dbf 40080

第二章 BBED基本命令

先看幫助的說明：

BBED> help all

SET DBA [ dba | file#, block# ]

SET FILENAME 'filename'

SET FILE file#

SET BLOCK [+/-]block#

SET OFFSET [ [+/-]byte offset | symbol |*symbol ]

SET BLOCKSIZE bytes

SET LIST[FILE] 'filename'

SET WIDTH character_count

SET COUNT bytes_to_display

SET IBASE [ HEX | OCT | DEC ]

SET OBASE [ HEX | OCT | DEC ]

SET MODE [ BROWSE | EDIT ]

SET SPOOL [ Y | N ]

SHOW [ <SET parameter> | ALL ]

INFO

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

</Nuf>:

N - a number which specifies a repeatcount.

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 displayformat:

x -hexadecimal

d -decimal

u -unsigned decimal

o -octal

c -character (native)

n -Oracle number

t -Oracle date

i -Oracle rowid

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

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

ASSIGN[/x|d|u|o] <targetspec>=<source spec>

<source spec> : [ value | <targetspec options> ]

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

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

POP [ALL]

REVERT [ DBA | FILE | FILENAME | BLOCK ]

UNDO

HELP [ <bbed command> | ALL ]

VERIFY [ DBA | FILE | FILENAME | BLOCK ]

CORRUPT [ DBA | FILE | FILENAME | BLOCK ]

下面是幾個經常使用的：

set 設定當前的環境

show 查看當前的環境參數，跟sqlplus的同名命令相似。

dump 列出指定block的內容

find 在指定的block中查找指定的字符串，結果是顯示出字符串，及其偏移量--offset，偏移量就是在block中的字節數

modify 修改指定block的指定偏移量的值，能夠在線修改。

copy 把一個block的內容copy到另外一個block中

verify 檢查當前環境是否有壞塊

sum 計算block的checksum，modify以後block就被標識爲壞塊，current checksum與reqired checksum不一致，sum命令能夠計算出新的checksum並應用到當前塊。

undo 回滾當前的修改操做，若是手誤作錯了，undo一下就ok了，回到原來的狀態。

revert 回滾全部以前的修改操做，意思就是 undo all

二.1 SET 命令

二.1.1 set dba

Set the current data block using the standard Oracle DBA (Data Block Address)format. This is entered as file_id, block.

關於DBA 說明，參考：Oracle rdba和 dba 說明 http://blog.csdn.net/tianlesoftware/article/details/6529346

select rowid,

dbms_rowid.rowid_relative_fno(rowid)rel_fno,

dbms_rowid.rowid_block_number(rowid)blockno,

dbms_rowid.rowid_row_number(rowid) rowno

from scott.emp;

set dba 4,145

若是設置成功，會返回該block的RDBA (Relative Data Block Address)，rdba就是rowid中的rfile#+block#。括號裏面的是DBA值和block 和 file id。咱們驗證一下：

sqlplus執行：

variable dba varchar2(30);

exec :dba :=dbms_utility.make_data_block_address(4,145);

print dba

二.1.2 set filename

Sets the current file to the one specified. It must be a valid Oracle data file andit must be enclosed in single quotes. If the file is not in the current path itmust also be fully qualified. If successful, bbed will respond showing the filenow being accessed.

BBED> set filename '/u01/app/oracle/oradata/dave2/users01.dbf'

FILENAME /u01/app/oracle/oradata/dave2/users01.dbf

--必須是一個有效的datafile，而且用單引號括起來

二.1.3 set file

Sets the current file to the number specified. The number specified must be one ofthe file ids supplied in the filelist referenced at startup. If successful,bbed will respond showing the file id now being accessed.

BBED> set file 4

FILE# 4

--注意這裏的number，是咱們以前配置的filelist裏的number。它能夠和咱們db 裏的file id 不同。不過最好是配置同樣的。

二.1.4 set block

Sets the current block. The block is relative to the filename or file already set.The absolute block can be specified, or an offset to the current block can bespecified using the plus (+) or (-) symbols. If successful, bbed will respondshowing the current block.

--注意這裏的block 是一個相對的位置，咱們須要先指定一個file，而後在指定block。即對應file裏的block。能夠對當前block的位置進行+和-操做。

BBED> set file 4

FILE# 4

BBED> set block 60882

BBED-00309: out of range block number(60882)

BBED> set file 1

FILE# 1

BBED> set block 60882

BLOCK# 60882

BBED> set bock +10

BBED-00202: invalid parameter (bock)

BBED> set block +10

BLOCK# 60892

BBED> set block -10

BLOCK# 60882

BBED> set file 4 block 520

FILE# 4

BLOCK# 520

BBED> set dba 4,520

DBA 0x01000208 (16777736 4,520)

二.1.5 set offset

Sets the current offset. The offset is relative to the block already set. Theabsolute offset can be specified, or an offset to the current offset can bespecified using the plus (+) or minus (-) symbols. If successful, bbed willrespond showing the current offset.

--偏移量是相對某個block裏的偏移量，能夠用+和-進行操做

BBED> set offset 20

OFFSET 20

BBED> set offset +2

OFFSET 22

BBED> set offset -2

OFFSET 20

二.1.6 set blocksize

Sets the blocksize of the current file. The blocksize must match the file selectedor an error will be reported. If successful, bbed will respond showing thecurrent blocksize.

設置當前datafile 的blocksize 大小，該大小必須和datafile 的實際block 匹配，不然會報錯。

BBED> set blocksize 8192

BLOCKSIZE 8192

二.1.7 set listfile

Sets the listfile to the specified file. This option can be used if the listfile wasnot specified on the command line. The listfile must be enclosed in singlequotes. If successful, bbed will respond showing the current listfile.

--在前面講過，能夠經過parameter file 來指定bbed的屬性，固然也能夠經過set 來指定這些信息。對於listfile的文件，必須用單引號括起來。

BBED> set listfile '/u01/filelist.txt'

LISTFILE /u01/filelist.txt

二.1.8 set width

Sets the current screen width. If not specified bbed will assume an 80-characterdisplay.

設定當前屏幕的寬度，默認是80.

BBED> set width 200

WIDTH 200

二.1.9 set count

Sets the number of bytes of the data block to display from the dump command. Thedefault is 512.

Tosee an entire 8Kb block therefore you would need to dump the block eight timesat offsets 0, 512, 1024, 1536, 2048, 2560, 3092 and 3604.

By setting the count higher bbed will dump more of the block each time. Byreducing it a smaller dump can be achieved.

設置dump 命令顯示bytes的數量。默認是512 bytes。

BBED> set count 512

COUNT 512

二.1.10 set ibase

Sets the internal number base. The default is decimal. However it can also be set tohexadecimal or octal. This allows the set file, set block and set offsetcommands to use an alternate base to decimal. If successful, bbed will respondshowing the current base:

--設置內部的數字格式，默認是十進制。也能夠設置爲十六進制或者八進制。設置完數字格式以後，但是使用該格式來設置blcok，offset等。

BBED> set ibase hex

IBASE Hex

BBED> set block +D

BLOCK# 14

BBED> set ibase decimal

IBASE Dec

二.1.11 set mode

Sets the bbed mode. The options are browse or edit. In browse mode no changes can bemade. This is the suggested mode for first-time users, or if you are intendingto use the tool only to inspect data blocks.

--設置bbed 的模式，該默認有2種：browse 和 edit。 browse 模式不容許進行修改。 若是要修改，就選擇edit模式。這個在咱們的以前的配置文件裏，咱們選擇了edit。

BBED> set mode browse

MODE Browse

BBED> set mode edit

MODE Edit

二.2 show 命令

顯示當前的配置選項。

show

BBED> show

FILE# 1

BLOCK# 14

OFFSET 0

DBA 0x0040000e(4194318 1,14)

--注意這裏的block 變成了14. 是咱們剛纔設置的。

FILENAME /u01/app/oracle/oradata/dave2/system01.dbf

BIFILE bifile.bbd

LISTFILE /u01/filelist.txt

BLOCKSIZE 8192

MODE Edit

EDIT Unrecoverable

IBASE Dec

OBASE Dec

WIDTH 200

COUNT 512

LOGFILE log.bbd

SPOOL No

二.3 info

顯示當前能夠進行browse 或者edit 的file。即咱們filelist 裏指定的datafile信息。

Info

二.4 map

The map command shows a map of the current block. It can be combined with the /voption to produce a more verbose output. The map shows the offsets throughout the block where certain information can be found such as the block header, the data block header or the row directory.

If the set commands have not been used to set a current block, or it the user simply wishes to examine another block while keeping the current block their focus,the file name, file id, block or DBA can be specified with the command.

Map會經過偏移量來顯示block裏的詳細信息，如block header，data block header 和row directory。使用/v 選項，能夠查看更詳細的信息。

在不指定block的狀況下，會顯示當前block的信息，若是想顯示其餘block的信息，可使用file name，file id，block 和DBA 來指定要顯示的block。

--經過dba 來指定某個block

map /v dba 4,145

Map 顯示的具體信息解釋以下：

struct kcbh, 20 bytes	Block Header Structure
ub1 type_kcbh	Block type (see Header Block Types below)
ub1 frmt_kcbh	Block format 1=Oracle 7, 2=Oracle 8+
ub1 spare1_kcbh	Not used
ub1 spare2_kcbh	Not used
ub4 rdba_kcbh	RDBA -Relative Data Block Address
ub4 bas_kcbh	SCN Base
ub2 wrp_kcbh	SCN Wrap
ub1 seq_kcbh	Sequence number, incremented for every change made to the block at the same SCN
ub1 flg_kcbh	Flag: 0x01 New Block 0x02 Delayed Logging Change advanced SCN/seq 0x04 Check value saved - block XOR‘s to zero 0x08 Temporary block
ub2 chkval_kcbh	Optional block checksum (if DB_BLOCK_CHECKSUM=TRUE)
ub2 spare3_kcbh	Not used
struct ktbbh, 72 bytes	Transaction Fixed Header Structure
ub1 ktbbhtyp	Block type (1=DATA, 2=INDEX)
union ktbbhsid, 4 bytes	Segment/Object ID
struct ktbbhcsc, 8 bytes	SCN at last block cleanout
b2 ktbbhict	Number of ITL slots
ub1 ktbbhflg	0=on the freelist
ub1 ktbbhfsl	ITL TX freelist slot
ub4 ktbbhfnx	DBA of next block on the freelist
struct ktbbhitl[2], 48 bytes	ITL list index
struct kdbh, 14 bytes	Data Header Structure
ub1 kdbhflag	N=pctfree hit(clusters); F=do not put on freelist; K=flushable cluster keys
b1 kdbhntab	Number of tables (>1 in clusters)
b2 kdbhnrow	Number of rows
sb2 kdbhfrre	First free row entry index; -1 = you have to add one
sb2 kdbhfsbo	Freespace begin offset
sb2 kdbhfseo	Freespace end offset
b2 kdbhavsp	Available space in the block
b2 kdbhtosp	Total available space when all TXs commit
struct kdbt[1], 4 bytes	Table Directory Entry Structure
b2 kdbtoffs
b2 kdbtnrow
sb2 kdbr[1]	Row Directory
ub1 freespace[8030]	Free Space
ub1 rowdata[38]	Row Data
ub4 tailchk	(See Tailchecks below)

Different block types are designated by the first byte of the block. The following tableshows how to decode the block type:

不一樣的block 能夠第一個byte的值是不同的。具體值對應block 類型以下。

Header Block Types

ID	Type
01	Undo segment header
02	Undo data block
03	Save undo header
04	Save undo data block
05	Data segment header (temp, index, data and so on)
06	KTB managed 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

能夠經過dump block來查看對應的具體的值。下文講dump時會有相關的示例。

oracleblocks 的最後4個bytes 是tail check。下面看一下oracle 9i block的tail check 組成。

Tailchecks

Thetail of an Oracle 8+ block is a concatenation of the lower order two bytes ofthe SCN base, the block type and the SCN sequence number.

Oracleblock tail 由4個bytes組成，但實際上只用了低2個bytes來存放。 2個bytes的tail 由scn base，block type 和 scn sequence 組成。

E.g, if the SCN base number is 0x00029728,the block type is 06 and the SCN sequence number is 0x02, the tail check wouldbe 0x97280602:

SCN base Type SCN seq

9728 06 02

Althoughthis tail check value is generated from three components, Oracle treats thefinal value as a single unsigned integer stored as a word (4-bytes). Onlittle-endian architecture machines, which include Intel, the value will bestores as low-order byte first.

雖然tail check 由3個部分組成，可是oracle 把這3部分做爲一個總體來存儲，而且佔用4個bytes。

對於little-endian（低端）架構的機器，包括Intel, 他們會先存放low-order byte，即低位字節。

Thereforeif the tail check is examined in the block using a standard block editor, orthe dump command which will be explained in the next section, the byte ordermay look different. A tail check of 0x97280602 stored on an Intel machine wouldbe written to disk as "02062897".

能夠經過標準block editor 或者dump 來查看tail check。對於不一樣的機器，他們存儲的順序是不同的。好比tail check 0x97280602 在Intel Machine 就被存儲爲02062897，由於它會先保存low-order bytes。

二.5 dump（d）

The dump command dumps the content of the block to the screen. It can be combinedwith the /v option to produce a more verbose output. TheDBA, Filename, File, Block and/or Offset to dump can be specified with thecommand. If these are not specified the current file, block and offsetas established with the set command will be dumped. The size of the dump islimited by the set count option and defaults to 512 bytes or alternatively thesize of the dump can be specified with the command.

dump命令能夠將block 的內容顯示到屏幕。每次顯示的bytes由count 控制，默認是512 bytes。使用 /v 選項，能夠顯示更多詳細信息。

dump /v dba 4,145 offset 0 count 128

二.6 examine(x)

The examine command is used to display data from the block in raw or formattedoutput. The DBA, Filename, File, Block and/or Offset to examine can bespecified with the command. If these are not specified the current file, blockand offset as established with the set command will be examined. If the examinecommand is issued with just the block and offset to examine, bbed will displaythe data structure at that offset.

--examine命令也是用來顯示datablock的內容的。

Unlikethe print command it cannot interpret data structures, but it can be used todisplay row information. Combined with knowledge of the data type of the row,it can be used to retrieve complete rows from the block:

--print命令不能對data structures 進行一個解釋說明。

The examine command will interpret the data in the block according to the followingswitches:

Switch	Display Format
/b	b1, ub1 (byte)
/h	b2, ub2 (half-word)
/w	b4, ub4 (word)
/l	b8, ub8 (long) (was b4/ub4 in Oracle7).
/r	Oracle table/index row

Theexamine command allows switches from the print command to be combined withthese specific switches to interpret data.

--examine能夠根據switch的方式和print 命令進行一個結合來對data 進行解釋說明。

Forexample if we wanted to interpret data as an Oracle table row with the firstcolumn character and the second and third columns numeric, we would execute thecommand as follows:

BBED>x /rcnn

Thefollowing example shows the print and examine commands being used to step throughthe first and second rows of a block, with the data interpreted as a row in theformat: character, number, number:

x /rcnn

select * from scott.emp;

二.7 find（f）

The find command is used to locate data within a block. The command allows hex,string or numeric data to be searched for. The pattern can be searched for fromthe top of the block (offset 0) using the TOP directive, or from the currentposition using the CURR directive.

find命令能夠用來搜索關鍵字。能夠從offset 0 搜索到top 或者從當前的offset 搜索到top。

Switchesare used to determine the data type of the pattern to search for. These areshown below:

Switch	Datatype
/x	Hexadecimal
/d	Decimal
/u	unsigned decimal
/o	Octal
/c	character (native)

Note: Number and Dates are not supported bythe find command.

find 命令支持的switch 類型如上表，注意，find 不支持number和Date 。

select rowid,

dbms_rowid.rowid_relative_fno(rowid)rel_fno,

dbms_rowid.rowid_block_number(rowid)blockno,

dbms_rowid.rowid_row_number(rowid) rowno

from scott.emp;

set file 4

set block 145

set offset 0

find /c SCOTT top

d /v dba 4,145 offset 7864 count 128

SCOTT

二.8 copy

The copy command is used to copy blocks from one location to another. As with other commands, the file or filename and offset can be specified, or the DBA can be specified instead.

能夠把一個塊的內容拷貝到另外一個塊中。

命令格式以下：

BBED> copy dba 1,115362 to dba 1,115363

copy 是個危險的命令，慎用。

二.9 modify（m）

BBED> help modify

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

BBED>

The modify command is used to change data inside a block. The DBA, Filename, File,Block and/or Offset to modify can be specified with the command. If these are not specified the current file, block and offset as established with the set command will be modified. Alternatively a symbol or symbol pointer can bespecified for modification.

The pattern of bytes used to overwrite the original can be specified inhexadecimal, decimal, unsigned decimal, octal or character data using the sameswitches as the find command.

能夠修改塊中的內容，該步驟不演示，下面實驗有。

在file 1,block 115362 有咱們的Dave，咱們這裏把Dave 改爲dmm。

modify /c HAHAH dba 4,31 offset 7864 該步驟不演示，下面實驗有。

d /v dba 4,31 offset 7864 count 128

select * from scott.emp;

如今無改變。

sum apply

重啓庫才能生效。

shutdown immediate;

startup

select * from scott.emp;

二.10 assign

The assign command does symbolic assignment, with type and range checking. Either target or source can be omitted for the current offset.

For example, the following command assigns structure at current offset to file 4,block 2 」s first ITL entry

BBED> assign dba 4, 145 ktbbhitl[0]

指定結構，不演示。

二.11 sum

Thesum command is used to check and set the block checksum. The DBA, Filename,File, Block and/or Offset to check can be specified with the command. If theseare not specified the current file, block and offset as established with theset command will be checked.

Theapply directive can be used to update the checksum.

咱們可使用bbed 對block 進行修改。要使這些修改生效，就要使用sum命令。

該步驟不演示，下面實驗有。

sum dba 4,31 apply 該步驟不演示，下面實驗有。

重啓庫或清除緩衝區才能生效。

二.12 push / pop

Thepush and pop commands are used to push a file, block and offset location onto amemory backed stack and then pop them back. This allows a current locationbeing edited to be temporarily saved while another location is examined ormodified.

Note that the stack only stores the locationœ it does notsave the contents.

--push命令將對象放到內存的stack，pop 將對象從內存寫回磁盤。

Thefollowing example shows file 7, block 16, offset 8163 being examined. Thelocation is saved with the push command. We then move to file 6, block 1 beforereturning to DBA 7,16 with the pop command.

BBED> push dba 7,16

DBA 0x01c00010 (29360144 7,16)

OFFSET 8163

BBED> set dba 6,1

DBA 0x01800001 (25165825 6,1)

BBED> pop

DBA 0x01c00010 (29360144 7,16)

OFFSET 8163

The command pop all can be used to remove all push‘d entries from the stack. Thecommand show all can be used to show all saved locations.

二.13 revert

Therevert command is used to restore a file, filename, block or DBA to it‘soriginal state when bbed was started.

revert是恢復自bbed 啓動以來的全部修改。

revert dba 4,31該步驟不演示，下面實驗有。

sum dba 4,31 apply

重啓庫才能看到變化。

shutdown immediate

startup

或者：

alter system flush buffer_cache;

select * from scott.emp;

仍是沒有改變，flush 一下buffer cache以後就更改回來了。咱們剛纔在以前的測試時，是重啓了DB。看來也是啓了flush buffer cache的做用。

二.14 undo

Theundo command rolls back the last modify or assign command. If the undo commandis issued again the modification is re-done.

undo命令是回滾最後一次的操做。

該步驟不演示，下面實驗有。

modify /c HAHAH dba 4,31 offset 7864該步驟不演示，下面實驗有。

d /v dba 4,31 offset 7864 count 128

sum apply

必定要提交。

若是不提交以前能夠

undo 該步驟不演示，下面實驗有。

alter system flush buffer_cache;

select * from scott.emp;

二.15 verify

Theverify command is used to verify the integrity of the block. It performs asimilar function to the dbverify utility.

verify命令用來驗證block的完整性。

verify dba 4,145

查看有沒有壞塊

二.16 corrupt

The corrupt command is used to mark blocks as media corrupt.

corrupt命令將一個block 標記爲corrupt，這樣db 在操做時就會跳過該block，從而避免錯誤。

verify dba 4,31 該步驟不演示，下面實驗有。

corrupt dba 4,31該步驟不演示，下面實驗有。

verify dba 4,31

注意： undo 命令不能undo 一個corruption，可是revert 命令卻能夠。

revert dba 4,31

sum apply

verify dba 4,31

二.17 修改數據塊中的內容

本例綜合運用上面的各類命令，修改塊的內容，並撤銷修改。

在sqlplus中操做

select * from scott.emp;

如今無改變。

select rowid,

dbms_rowid.rowid_relative_fno(rowid)rel_fno,

dbms_rowid.rowid_block_number(rowid)blockno,

dbms_rowid.rowid_row_number(rowid) rowno

from scott.emp;

在bbed中操做

set dba 4,145 offset 0

find /c SCOTT top

dump /v dba 4,145 offset 7864 count 128

注意這裏面的Offsets:7864 to 7991，它指的是這一行的一個地址。其中

S 的offset 是7864

C 的offset 是7865

O 的offset 是7866

T 的offset 是7867

空格也算offset。

modify /c HAHAH dba 4,145 offset 7864

sum apply

或者

sum dba 4,145 apply

dump /v dba 4,145 offset 7864 count 128

在sqlplus中操做

alter system flush buffer_cache;

select * from scott.emp;

二.17.1 下面撤銷修改：

在bbed中操做

revert dba 4,145

sum dba 4,145 apply

在sqlplus中操做

alter system flush buffer_cache;

select * from scott.emp;

二.18 恢復delete的rows

When rows are deleted in Oracle the data is not actually removed. The row is simply marked as deleted and the free space counters and pointers adjusted accordingly. The status of a row is stored in the Row Header which occupies the first few bytes of each row.

當row 被delete 的時候，實際上data 並無被remove，只是將該row 標記爲delete，而後其對應的空間被統計爲free space。 row 的status 存在每一個row的row header裏。

The Row Header consists of the Row Flag, Lock Byte (ITL entry) and Column Count.The first of these - the Row Flag - is a single byte that holds a bitmask thatshows the status of the row. The bitmask is decoded as follows:

RowHeader 包含Row Flag，Lock Byte（ITL）和column Count。其中Row Flag佔用1個byte，而且以bitmask 來保存。bitmask 的解釋以下：

Cluster Key

Cluster Table Member

Head of row piece

Deleted

First data piece

Last data piece

1st Column continues from previous piece

Last column continues in next piece

128

二.18.1 刪除前

在sqlplus中操做

select * from scott.emp;

select rowid,

dbms_rowid.rowid_relative_fno(rowid)rel_fno,

dbms_rowid.rowid_block_number(rowid)blockno,

dbms_rowid.rowid_row_number(rowid) rowno

from scott.emp;

col segment_name for a10

select extent_id,segment_name,bytes/1024 k,file_id,block_id from dba_extents where owner='SCOTT';

alter system checkpoint;

alter system dump datafile 4 block 145;

查詢dump到哪一個trace文件中：

oradebug setmypid

oradebug tracefile_name

more /u01/app/oracle/oradata/PROD/dump/diag/rdbms/prod/PROD/trace/PROD_ora_6241.trc

能夠看到這個表有14條記錄。

注意這裏的fb: --H-FL--。其有8個選項，每一個值分別與bitmask 對應。

Therefore,columns that fit within a single block, are not chained, migrated or part of aclustered table and are not deleted will have the following attributes:

（1）Head of Row Piece

（2）First Data Piece

（3）Last Data Piece

若是一個row 沒有被刪除，那麼它就具備上面的3個屬性，即Flag 表示爲：--H-FL--. 這裏的字母分別表明屬性的首字母。其對應的值：32 + 8 + 4 =44 or 0x2c.

若是一個row 被delete了，那麼row flag 就會更新，bitmask 裏的deleted 被設置爲16. 此時row flag 爲： 32 + 16 + 8 + 4 = 60 or 0x3c.

delete from scott.emp where empno=7900;

commit;

select * from scott.emp;

二.18.2 刪除後

alter system checkpoint;

alter system dump datafile 4 block 145;

查詢dump到哪一個trace文件中：

oradebug setmypid

oradebug tracefile_name

more /u01/app/oracle/oradata/PROD/dump/diag/rdbms/prod/PROD/trace/PROD_ora_6241.trc

注意上面的標籤被刪除的數據是HDFL，通常是H-FL。

如今咱們用bbed 將刪除的內容找回來。

在bbed中操做

set dba 4,145 offset 0

find /c JAMES top

dump /v dba 4,145 offset 7706 count 128

d /v dba 4,145 offset 7705 count 128

比剛剛多了兩個字符。

8個字符纔是一個完整的信息，因此要改變4個偏移量才能展現完整的信息。

7706-8=7698，再加1=7699.

尋找原則：和row directory覈對，尋找前面最接近的值。

d /v dba 4,145 offset 7699

這裏已經出現了咱們3c（deleted）標誌，可是注意這裏的位置的根據咱們的查找的字符串來分的，實際在block裏的分割方式不同按照咱們的offset 來進行。咱們能夠經過row directory 來進行一個確認。

驗證一下

p kdbr

p *kdbr[9]

p *kdbr[10]

p *kdbr[11]

p *kdbr[12]

肯定7699就是3c的開頭。

modify /x 2c offset 7699

sum apply

在sqlplus中操做

alter system flush buffer_cache;

select * from scott.emp;

以前delete 的數據已經恢復出來。

可是：

系統認爲已經刪掉了。

select count(*) from scott.emp;

alter table scott.emp move;

二.19 使用copy命令從舊數據文件中恢復delete的rows

將表scott.emp移動到咱們的單獨的datafile裏(目的是查找清晰，並恢復上面的破壞)：

col tablespace_name for a15

select tablespace_name,contents,status from dba_tablespaces;

col name for a50

select file#,name from v$datafile;

create tablespace lxtbs datafile '/u01/app/oracle/oradata/PROD/disk3/lxtbs01.dbf' size 50m;

alter table scott.emp move tablespace lxtbs;

alter index scott.pk_emp rebuild tablespace lxtbs;

col table_name for a10

select table_name,tablespace_name,blocks from dba_tables where owner='SCOTT';

select * from scott.emp;

select file#||' '||name||' '||bytes from v$datafile;

二.19.1 建立一箇舊的數據文件

shutdown immediate;

關庫後再操做：

cp /u01/app/oracle/oradata/PROD/disk3/lxtbs01.dbf /home/oracle

cd /home/oracle

將copy 的bak datafile 添加到bbed 的parfile裏面

vi file.txt

添加：

6 /u01/app/oracle/oradata/PROD/disk3/lxtbs01.dbf 52428800

7 /home/oracle/lxtbs01.dbf 52428800

最後的7號文件是咱們添加的。

startup

select rowid,

dbms_rowid.rowid_relative_fno(rowid)rel_fno,

dbms_rowid.rowid_block_number(rowid)blockno,

dbms_rowid.rowid_row_number(rowid) rowno

from scott.emp;

col owner for a10

col segment_name for a10

select owner,segment_name,header_file,header_block,blocks from dba_segments where owner='SCOTT';

從這個查詢結果，咱們能夠看到，對象保存在datafile 6裏，從130 的block 開始存儲，佔用8個blocks。

這裏要注意的一點是：dba_segments 視圖裏的block 是從0開始的統計的，而bbed 裏是從1. 因此咱們在bbed中指定block時，須要加1（130會報錯），也就是131

quit

bbed parfile=/home/oracle/bbed.par

blockedit

下面能查出東西來就行。

set dba 6,130 offset 0

p ktbbh

set dba 6,131 offset 0

p ktbbh

作一個誤刪除操做:

delete from scott.emp;

commit;

select * from scott.emp;

二.19.2 使用copy 從舊的datafile裏恢復

set width 70

info

其中7是咱們的舊的數據文件。

copy dba 7,131 to dba 6,131

copy剩下的7個塊：

copy dba 7,132 to dba 6,132

copy dba 7,133 to dba 6,133

copy dba 7,134 to dba 6,134

copy dba 7,135 to dba 6,135

copy dba 7,136 to dba 6,136

copy dba 7,137 to dba 6,137

copy dba 7,138 to dba 6,138

sum apply

alter system flush buffer_cache;

select * from scott.emp;

若是出不來就再作一遍copy,數據就回來了，或者重啓db數據也能回來。

可是：

select count(*) from scott.emp;

須要再move一次。

alter table scott.emp move tablespace users;

alter index scott.pk_emp rebuild tablespace users;

alter table scott.emp move tablespace lxtbs;

alter index scott.pk_emp rebuild tablespace lxtbs;

select count(*) from scott.emp;

二.20 壞塊恢復（Rman Blockrecover）

有些人喜歡用bbed幹一些弄簡爲繁的事情，好比控制文件丟失，或者介質故障開不了庫，手工修改scn號開庫，或壞塊修復等。若是不是高手，最好不要用bbed進行高風險的工做，其實Oracle Rman提供了修復壞塊的工具block recover。但前提條件是你得有一個可用的備份存在。

最好從新作一次備份：

rman target /

delete noprompt backup;

delete noprompt copy;

list backup;

list copy;

run{

shutdown immediate;

startup mount;

allocate channel c1 type disk;

allocate channel c2 type disk;

backup database format '/home/oracle/rman_bak/cold_bak/%d_%s_%p.bak';

alter database open;

}

run{

sql 'alter system switch logfile';

allocate channel c1 type disk;

allocate channel c2 type disk;

backup database format '/home/oracle/rman_bak/hot_bak/%d_%s_%p_hot.bak' filesperset 3;

sql 'alter system switch logfile';

}

/************************從新登陸*************************/

sqlplus從新登陸：

quit

sqlplus '/as sysdba'

bbed從新登陸

quit

bbed parfile=/home/oracle/bbed.par

blockedit

/************************從新登陸*************************/

二.20.1 製做壞塊

先用bbed搞壞數據塊。

select rowid,

dbms_rowid.rowid_relative_fno(rowid)rel_fno,

dbms_rowid.rowid_block_number(rowid)blockno,

dbms_rowid.rowid_row_number(rowid) rowno

from scott.dept;

col segment_name for a10

select owner,segment_name,header_file,header_block,blocks from dba_segments where owner='SCOTT';

加一變成129.

set dba 4,128 offset 0

p ktbbh

set dba 4,129 offset 0

p ktbbh

map

d /v offset 0 count 128

modify /x 12345678 offset 0 單步執行，或copy命令製做壞塊

sum apply

d /v offset 0 count 128

alter system flush buffer_cache;

select * from scott.dept;

--當Oracle 認爲一個block 是corrupt時，會將該block的sequence number 標記爲0xff. 該值能夠經過seq_kcbh 屬性查看。

set dba 4,129

p kcbh

verify dba 4,129

二.20.2 恢復壞塊

不建議使用bbed來操做，rman有工具能夠很好的處理，bbed作的話就是revert回去就行了。

BBED> revert

All changes made in this session will be rolled back. Proceed? (Y/N) Y

Reverted file '/oracle/app/oracle/oralhr/users01.dbf', block 520

Reverted file '/oracle/app/oracle/oralhr/users01.dbf', block 523

Warning: contents of previous BIFILE will be lost. Proceed? (Y/N) Y

下邊來嘗試rman恢復：

rman target /

不要執行：只適用於一兩個壞塊 blockrecover datafile 4 block 129,130;

若是有多個壞塊，最好先校驗：

backup validate datafile 4;

select * from v$database_block_corruption;

修復所有壞塊。

blockrecover corruption list;

alter system flush buffer_cache;

select * from scott.dept;

用rman的備份，修復了這個塊。

select * from v$database_block_corruption;

set dba 4,129

d /v offset 0 count 128

二.20.3 壞塊的影響

再次搞壞數據塊：

set dba 4,129

d /v offset 0 count 128

modify /x 12345678 offset 0

sum apply

alter system flush buffer_cache;

select * from scott.dept;

rman內操做：

backup datafile 4;

RMAN> backup datafile 4;

Starting backup at 2016-04-06 14:25:42

using channel ORA_DISK_1

channel ORA_DISK_1: starting full datafile backup set

channel ORA_DISK_1: specifying datafile(s) in backup set

input datafile file number=00004 name=/oracle/app/oracle/oralhr/users01.dbf

channel ORA_DISK_1: starting piece 1 at 2016-04-06 14:25:42

RMAN-00571: ===========================================================

RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============

RMAN-00571: ===========================================================

RMAN-03009: failure of backup command on ORA_DISK_1 channel at 04/06/2016 14:25:45

ORA-19566: exceeded limit of 0 corrupt blocks for file /oracle/app/oracle/oralhr/users01.dbf

col tablespace_name for a10

col owner for a10

col PARTITION_NAME for a10

SELECT tablespace_name,segment_type,owner,segment_name,partition_name

FROM dba_extents

WHERE file_id = &file_id AND &block_id BETWEEN block_id AND block_id+blocks-1;

輸入：

129

run{

set maxcorrupt for datafile 4 to 2;

backup datafile 4 tag='2corruptblock';

}

這樣才能備份，可是推薦先修復壞塊：

backup validate datafile 4;

blockrecover corruption list;

backup datafile 4;

About Me

..........................................................................................................................................................................................................

● 本文做者：小麥苗，只專一於數據庫的技術，更注重技術的運用

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