Oracle的DBV命令行工具用法詳解
DBV(DBVERIFY)是Oracle提供的一個命令行工具，它可以對數據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據記錄的匹配關系，這種檢查必須使用analyze validate structure命令。
這個工具有如下特點：
- 以只讀的方式打開數據文件，在檢查過程中不會修改數據文件的內容。
- 可以在線檢查數據文件，而不需要關閉數據庫。
- 不能檢查控制文件和日志文件，只能檢查數據文件。
- 這個工具可以檢查ASM文件，但數據庫必須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
- 在許多UNIX平臺下，DBV要求數據文件有擴展名，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
- 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。
- DBV只會檢查數據塊的正確性，但不會關系數據塊是否屬于哪個對象。
- 對于祼設備建議指定END參數，避免超出數據文件范圍。比如：dbv FILE=/dev/rdsk/r1.dbf END=<last_block_number>?？梢栽趘$datafile視圖中用bytes字段除以塊大小來獲得END值。
參數 含義 缺省值
FILE 要檢查的數據文件名 沒有缺省值
START 檢查起始數據塊號 數據文件的***個數據塊
END 檢查的***一個數據塊號 數據文件的***一個數據塊
BLOCKSIZE 數據塊大小，這個值要和數據庫的DB_BLOCK_SIZE參數值一致 缺省值8192
LOGFILE 檢查結果日志文件 沒有缺省值
FEEDBAK 顯示進度 0
PARFILE 參數文件名 沒有缺省值
USERID 用戶名、密碼 沒有缺省值
SEGMENT_ID 段ID，參數格式<tsn.segfile.segblock> 沒有缺省值
使用示例：
- [oracle@rhel6 ~]$ 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。從上面的檢查結果Total Pages Marked Corrupt : 0可以看出文件沒有壞塊。
除了檢查數據文件，這個工具還允許檢查單獨的Segment，這時參數值的格式為<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$tablespace t,dba_segments s
- 3 where s.segment_name='T'
- 4 and t.name=s.tablespace_name;
- TS# HEADER_FILE HEADER_BLOCK
- ---------- ----------- ------------
- 4 4 45834
從上面的查詢結果可行參數值為4.4.45834。檢查Segment：
- [oracle@rhel6 ~]$ 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.
當前數據文件沒有壞塊
- [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文件中的數據文件，需要指定userid參數
- [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)
