DBV(DBVERIFY)工具
DBV(DBVERIFY)是Oracle提供的一個命令行工具，它可以對數(shù)據(jù)文件物理和邏輯兩種一致性檢查。但是這個工具不會檢查索引記錄和數(shù)據(jù)記錄的匹配關(guān)系，這種檢查必須使用analyze validate structure命令。
這個工具有如下特點：
1以只讀的方式打開數(shù)據(jù)文件，在檢查過程中不會修改數(shù)據(jù)文件的內(nèi)容。
2可以在線檢查數(shù)據(jù)文件，而不需要關(guān)閉數(shù)據(jù)庫。
3不能檢查控制文件和日志文件，只能檢查數(shù)據(jù)文件。
4這個工具可以檢查ASM文件，但數(shù)據(jù)庫必須Open狀態(tài)，并且需要通過USERID指定用戶，比如：dbv file=+DG1/ORCL/datafile/system01.dbf userid=system/sys
5在許多UNIX平臺下，DBV要求數(shù)據(jù)文件有擴展名，如果沒有可以通過建立鏈接的方法，然后對鏈接的方法，然后對鏈接文件進行操作，比如：ls -n /dev/rdsk/mydevice /tmp/mydevice.dbf
6某些平臺，DBV工具不能檢查超過2GB的文件，如果碰到DBV-100錯誤，請先檢查文件大小，MOS Bug 710888對這個問題有描述。
7DBV只會檢查數(shù)據(jù)塊的正確性，但不會關(guān)系數(shù)據(jù)塊是否屬于哪個對象。
8對于祼設(shè)備建議指定END參數(shù)，避免超出數(shù)據(jù)文件范圍。比如：dbv FILE=/dev/rdsk/r1.dbf END=<last_block_number>?？梢栽趘$datafile視圖中用bytes字段除以塊大小來獲得END值。
參數(shù)含義缺省值
FILE要檢查的數(shù)據(jù)文件名沒有缺省值
START檢查起始數(shù)據(jù)塊號數(shù)據(jù)文件的第一個數(shù)據(jù)塊
END檢查的最后一個數(shù)據(jù)塊號數(shù)據(jù)文件的最后一個數(shù)據(jù)塊
BLOCKSIZE數(shù)據(jù)塊大小，這個值要和數(shù)據(jù)庫的DB_BLOCK_SIZE參數(shù)值一致缺省值8192
LOGFILE檢查結(jié)果日志文件沒有缺省值
FEEDBAK顯示進度0
PARFILE參數(shù)文件名沒有缺省值
USERID用戶名、密碼沒有缺省值
SEGMENT_ID段ID，參數(shù)格式<tsn.segfile.segblock>沒有缺省值
使用示例：
[oracle@rhel6 ~]$ dbv file=/u01/app/oracle/oradata/test/users01.dbf
DBVERIFY: Release 11.2.0.1.0 - Production on Mon May 22 16:42:26 2017
Copyright (c) 1982, 2009, Oracle and/or its affiliates. All rights reserved.
DBVERIFY - Verification starting : FILE = /u01/app/oracle/oradata/test/users01.dbf
DBVERIFY - Verification complete
Total Pages Examined : 155520
Total Pages Processed (Data) : 144530
Total Pages Failing (Data) : 0
Total Pages Processed (Index): 52
Total Pages Failing (Index): 0
Total Pages Processed (Other): 1248
Total Pages Processed (Seg) : 0
Total Pages Failing (Seg) : 0
Total Pages Empty : 9690
Total Pages Marked Corrupt : 0
Total Pages Influx : 0
Total Pages Encrypted : 0
Highest block SCN : 3559792 (0.3559792)
這個工具報告使用的是page作為單位，含義和data block相同。從上面的檢查結(jié)果Total Pages Marked Corrupt : 0可以看出文件沒有壞塊。
除了檢查數(shù)據(jù)文件，這個工具還允許檢查單獨的Segment，這時參數(shù)值的格式為<tsn.segfile.segblock>
查看對象的tsn,segfile,segblock屬性：
zx@TEST>select t.ts#,s.header_file,s.header_block
2 from v$tablespace t,dba_segments s
3 where s.segment_name='T'
4 and t.name=s.tablespace_name;
TS# HEADER_FILE HEADER_BLOCK
---------- ----------- ------------
4 4 45834
從上面的查詢結(jié)果可行參數(shù)值為4.4.45834。檢查Segment：
[oracle@rhel6 ~]$ dbv userid=system/123456 segment_id=4.4.45834
DBVERIFY: Release 11.2.0.1.0 - Production on Mon May 22 20:58:33 2017
Copyright (c) 1982, 2009, Oracle and/or its affiliates. All rights reserved.
DBVERIFY - Verification starting : SEGMENT_ID = 4.4.45834
DBVERIFY - Verification complete
Total Pages Examined : 8
Total Pages Processed (Data) : 5
Total Pages Failing (Data) : 0
Total Pages Processed (Index): 0
Total Pages Failing (Index): 0
Total Pages Processed (Other): 2
Total Pages Processed (Seg) : 1
Total Pages Failing (Seg) : 0
Total Pages Empty : 0
Total Pages Marked Corrupt : 0
Total Pages Influx : 0
Total Pages Encrypted : 0
Highest block SCN : 3518579 (0.3518579)
下面人為創(chuàng)造一個壞塊，用dbv來檢查。
創(chuàng)建一個測試表
zx@TEST>create table bbed (id number,name varchar2(20)) tablespace users;
Table created.
zx@TEST>insert into bbed values(1,'zhaoxu');
1 row created.
zx@TEST>commit;
Commit complete.
當前數(shù)據(jù)文件沒有壞塊
[oracle@rhel6 ~]$ dbv file=/u01/app/oracle/oradata/test/users01.dbf
DBVERIFY: Release 11.2.0.1.0 - Production on Mon May 22 21:03:40 2017
Copyright (c) 1982, 2009, Oracle and/or its affiliates. All rights reserved.
DBVERIFY - Verification starting : FILE = /u01/app/oracle/oradata/test/users01.dbf
DBVERIFY - Verification complete
Total Pages Examined : 155520
Total Pages Processed (Data) : 66397
Total Pages Failing (Data) : 0
Total Pages Processed (Index): 52
Total Pages Failing (Index): 0
Total Pages Processed (Other): 88898
Total Pages Processed (Seg) : 0
Total Pages Failing (Seg) : 0
Total Pages Empty : 173
Total Pages Marked Corrupt : 0
Total Pages Influx : 0
Total Pages Encrypted : 0
Highest block SCN : 3764775 (0.3764775)
獲取表在文件中的存儲信息
zx@TEST>set serveroutput on
zx@TEST>declare rfno number;
2 rtype number;
3 ono number;
4 blkno number;
5 rowno number;
6 rid varchar2(30);
7 begin
8 select rowid into rid from bbed;
9 dbms_rowid.rowid_info(ROWID_IN=>rid,RELATIVE_FNO=>rfno,BLOCK_NUMBER=>blkno,ROW_NUMBER=>rowno,ROWID_TYPE=>rtype,OBJECT_NUMBER=>ono);
10 dbms_output.put_line(rfno||','||blkno||','||rowno);
11 end;
12 /
4,45844,0
PL/SQL procedure successfully completed.
使用bbed修改塊信息
[oracle@rhel6 bbed]$ bbed parfile=bbed.par
Password:
BBED: Release 2.0.0.0.0 - Limited Production on Mon May 22 21:17:18 2017
Copyright (c) 1982, 2009, Oracle and/or its affiliates. All rights reserved.
************* !!! For Oracle Internal Use only !!! ***************
BBED> set dba 4,45844
DBA 0x0100b314 (16823060 4,45844)
BBED> find /c zhaoxu
File: /u01/app/oracle/oradata/test/users01.dbf (4)
Block: 45844 Offsets: 8182 to 8191 Dba:0x0100b314
------------------------------------------------------------------------
7a68616f 78750106 5873
<32 bytes per line>
BBED> dump /v dba 4,45844 offset 8182 count 32
File: /u01/app/oracle/oradata/test/users01.dbf (4)
Block: 45844 Offsets: 8182 to 8191 Dba:0x0100b314
-------------------------------------------------------
7a68616f 78750106 5873 l zhaoxu..Xs
<16 bytes per line>
BBED> modify 100 dba 4,45844
Warning: contents of previous BIFILE will be lost. Proceed? (Y/N) y
File: /u01/app/oracle/oradata/test/users01.dbf (4)
Block: 45844 Offsets: 8182 to 8191 Dba:0x0100b314
------------------------------------------------------------------------
6468616f 78750106 5873
<32 bytes per line>
BBED> dump /v dba 4,45844 offset 8182 count 32
File: /u01/app/oracle/oradata/test/users01.dbf (4)
Block: 45844 Offsets: 8182 to 8191 Dba:0x0100b314
-------------------------------------------------------
6468616f 78750106 5873 l dhaoxu..Xs
<16 bytes per line>
BBED> exit
再次使用dbv檢查文件
[oracle@rhel6 bbed]$ dbv file=/u01/app/oracle/oradata/test/users01.dbf
DBVERIFY: Release 11.2.0.1.0 - Production on Mon May 22 21:18:46 2017
Copyright (c) 1982, 2009, Oracle and/or its affiliates. All rights reserved.
DBVERIFY - Verification starting : FILE = /u01/app/oracle/oradata/test/users01.dbf
Page 45844 is marked corrupt
Corrupt block relative dba: 0x0100b314 (file 4, block 45844)
Bad check value found during dbv:
Data in bad block:
type: 6 format: 2 rdba: 0x0100b314
last change scn: 0x0000.00397358 seq: 0x1 flg: 0x04
spare1: 0x0 spare2: 0x0 spare3: 0x0
consistency value in tail: 0x73580601
check value in block header: 0x7c2d
computed block checksum: 0x1e
DBVERIFY - Verification complete
Total Pages Examined : 155520
Total Pages Processed (Data) : 66396
Total Pages Failing (Data) : 0
Total Pages Processed (Index): 52
Total Pages Failing (Index): 0
Total Pages Processed (Other): 88898
Total Pages Processed (Seg) : 0
Total Pages Failing (Seg) : 0
Total Pages Empty : 173
Total Pages Marked Corrupt : 1
Total Pages Influx : 0
Total Pages Encrypted : 0
Highest block SCN : 3764775 (0.3764775)
報告一個壞塊，Total Pages Marked Corrupt : 1
再次查詢測試表：
sys@TEST>select * from zx.bbed;
ID NAME
---------- ------------------------------------------------------------
1 zhaoxu
查詢正常，因為在buffer_cache中緩存了塊，而修改的是文件中的塊。兩個塊現(xiàn)在不一致，清空buffer cache后再次查詢測試表。
zx@TEST>alter system flush buffer_cache;
System altered.
zx@TEST>select * from bbed;
select * from bbed
*
ERROR at line 1:
ORA-01578: ORACLE data block corrupted (file # 4, block # 45844)
ORA-01110: data file 4: '/u01/app/oracle/oradata/test/users01.dbf'
查詢報出錯誤ORA-01578。
使用dbv檢查ASM文件中的數(shù)據(jù)文件，需要指定userid參數(shù)
[oracle@rac1 ~]$ dbv file=+DATA/orcl/datafile/users.259.925306091 userid=sys/123456
DBVERIFY: Release 11.2.0.4.0 - Production on Mon May 22 16:48:22 2017
Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.
DBVERIFY - Verification starting : FILE = +DATA/orcl/datafile/users.259.925306091
DBVERIFY - Verification complete
Total Pages Examined : 640
Total Pages Processed (Data) : 16
Total Pages Failing (Data) : 0
Total Pages Processed (Index): 2
Total Pages Failing (Index): 0
Total Pages Processed (Other): 593
Total Pages Processed (Seg) : 0
Total Pages Failing (Seg) : 0
Total Pages Empty : 29
Total Pages Marked Corrupt : 0
Total Pages Influx : 0
Total Pages Encrypted : 0
Highest block SCN : 0 (0.0)
轉(zhuǎn)載自：https://www.linuxidc.com/Linux/2017-05/144202.htm
