一. 理解什么是數(shù)據(jù)庫恢復(fù)
當(dāng)我們使用一個(gè)數(shù)據(jù)庫時(shí),總希望數(shù)據(jù)庫的內(nèi)容是可靠的、正確的,但由于計(jì)算機(jī)系統(tǒng)的故障(硬件故障、軟件故障、網(wǎng)絡(luò)故障、進(jìn)程故障和系統(tǒng)故障)影響數(shù)據(jù)庫系統(tǒng)的操作,影響數(shù)據(jù)庫中數(shù)據(jù)的正確性,甚至破壞數(shù)據(jù)庫,使數(shù)據(jù)庫中全部或部分?jǐn)?shù)據(jù)丟失。因此當(dāng)發(fā)生上述故障后,希望能重構(gòu)這個(gè)完整的數(shù)據(jù)庫,該處理稱為數(shù)據(jù)庫恢復(fù)?;謴?fù)過程大致可以分為復(fù)原(Restore)與恢復(fù)(Recover)過程。
數(shù)據(jù)庫恢復(fù)可以分為以下兩類:
1.1實(shí)例故障的一致性恢復(fù)
當(dāng)實(shí)例意外地(如掉電、后臺(tái)進(jìn)程故障等)或預(yù)料地(發(fā)出SHUTDOUM ABORT語句)中止時(shí)出現(xiàn)實(shí)例故障,此時(shí)需要實(shí)例恢復(fù)。實(shí)例恢復(fù)將數(shù)據(jù)庫恢復(fù)到故障之前的事務(wù)一致狀態(tài)。如果在在線后備發(fā)現(xiàn)實(shí)例故障,則需介質(zhì)恢復(fù)。在其它情況Oracle在下次數(shù)據(jù)庫起動(dòng)時(shí)(對(duì)新實(shí)例裝配和打開),自動(dòng)地執(zhí)行實(shí)例恢復(fù)。如果需要,從裝配狀態(tài)變?yōu)榇蜷_狀態(tài),自動(dòng)地激發(fā)實(shí)例恢復(fù),由下列處理:
(1) 為了解恢復(fù)數(shù)據(jù)文件中沒有記錄的數(shù)據(jù),進(jìn)行向前滾。該數(shù)據(jù)記錄在在線日志,
包括對(duì)回滾段的內(nèi)容恢復(fù)。
(2) 回滾未提交的事務(wù),按步1重新生成回滾段所指定的操作。
(3) 釋放在故障時(shí)正在處理事務(wù)所持有的資源。
(4) 解決在故障時(shí)正經(jīng)歷一階段提交的任何懸而未決的分布事務(wù)。
1.2介質(zhì)故障或文件錯(cuò)誤的不一致恢復(fù)
介質(zhì)故障是當(dāng)一個(gè)文件、一個(gè)文件的部分或磁盤不能讀或不能寫時(shí)出現(xiàn)的故障。文件錯(cuò)誤一般指意外的錯(cuò)誤導(dǎo)致文件被刪除或意外事故導(dǎo)致文件的不一致。這種狀態(tài)下的數(shù)據(jù)庫都是不一致的,需要DBA手工來進(jìn)行數(shù)據(jù)庫的恢復(fù),這種恢復(fù)有兩種形式,決定于數(shù)據(jù)庫運(yùn)行的歸檔方式和備份方式。
(1) 完全介質(zhì)恢復(fù)可恢復(fù)全部丟失的修改。一般情況下需要有數(shù)據(jù)庫的備份且數(shù)據(jù)庫運(yùn)行在歸檔狀態(tài)下并且有可用歸檔日志時(shí)才可能。對(duì)于不同類型的錯(cuò)誤,有不同類型的完全恢復(fù)可使用,其決定于毀壞文件和數(shù)據(jù)庫的可用性。
(2) 不完全介質(zhì)恢復(fù)是在完全介質(zhì)恢復(fù)不可能或不要求時(shí)進(jìn)行的介質(zhì)恢復(fù)。重構(gòu)受損的數(shù)據(jù)庫,使其恢復(fù)介質(zhì)故障前或用戶出錯(cuò)之前的一個(gè)事務(wù)一致性狀態(tài)。不完全介質(zhì)恢復(fù)有不同類型的使用,決定于需要不完全介質(zhì)恢復(fù)的情況,有下列類型:基于撤消、基于時(shí)間和基于修改的不完全恢復(fù)。
基于撤消(CANCEL)恢復(fù):在某種情況,不完全介質(zhì)恢復(fù)必須被控制,DBA可撤消在指定點(diǎn)的操作?;诔废幕謴?fù)地在一個(gè)或多個(gè)日志組(在線的或歸檔的)已被介質(zhì)故障所破壞,不能用于恢復(fù)過程時(shí)使用,所以介質(zhì)恢復(fù)必須控制,以致在使用最近的、未損的日志組于數(shù)據(jù)文件后中止恢復(fù)操作。
基于時(shí)間(TIME)和基于修改(SCN)的恢復(fù):如果DBA希望恢復(fù)到過去的某個(gè)指定點(diǎn),是一種理想的不完全介質(zhì)恢復(fù),一般發(fā)生在恢復(fù)到某個(gè)特定操作之前,恢復(fù)到如意外刪除某個(gè)數(shù)據(jù)表之前。
第二章. 數(shù)據(jù)庫恢復(fù)案例測試環(huán)境
2.1 數(shù)據(jù)庫環(huán)境
以下的所有案例都是通過測試經(jīng)過,環(huán)境為:
OS:Windows 2000 Server
DB:Oracle 816
DBNAME:TEST
數(shù)據(jù)文件:
SQL> select file#,status,enabled,name from v$datafile;
FILE# STATUS ENABLED NAME
----------------------------------------------------------------
1 SYSTEM READ WRITE D:\Oracle\ORADATA\TEST\SYSTEM01.DBF
2 ONLINE READ WRITE D:\Oracle\ORADATA\TEST\RBS01.DBF
3 ONLINE READ WRITE D:\Oracle\ORADATA\TEST\USERS01.DBF
4 ONLINE READ WRITE D:\Oracle\ORADATA\TEST\TEMP01.DBF
5 ONLINE READ WRITE D:\Oracle\ORADATA\TEST\TOOLS01.DBF
6 ONLINE READ WRITE D:\Oracle\ORADATA\TEST\INDX01.DBF
控制文件:
SQL> select * from v$controlfile;
STATUS NAME
---------------------------------------------------------------------
D:\Oracle\ORADATA\TEST\CONTROL01.CTL
D:\Oracle\ORADATA\TEST\CONTROL02.CTL
D:\Oracle\ORADATA\TEST\CONTROL03.CTL
聯(lián)機(jī)日志:
SQL> select * from v$logfile;
GROUP# STATUS MEMBER
---------------------------------------------------------------------
1 STALE D:\Oracle\ORADATA\TEST\REDO01.LOG
2 D:\Oracle\ORADATA\TEST\REDO02.LOG
3 STALE D:\Oracle\ORADATA\TEST\REDO03.LOG
2.2 數(shù)據(jù)庫備份腳本
冷備份腳本:
rem script:coldbak.sql
rem creater:chenjiping
rem date:5.8.2003
rem desc:offline full backup database
--connect database
connect internal/password;
--shutdown database
shutdown immediate;
--Copy Data file
!xcopy d:\Oracle\oradata\test\*.dbf d:\database/H/R;
--Copy Control file
!xcopy d:\Oracle\oradata\test\*.ctl d:\database/H/R;
--Copy Log file
!xcopy d:\Oracle\oradata\test\*.log d:\database/H/R;
--startup database
startup;
說明:
1、以上腳本在數(shù)據(jù)庫關(guān)閉狀態(tài)下備份數(shù)據(jù)庫所有的數(shù)據(jù)文件,聯(lián)機(jī)日志,控制文件(在一個(gè)目
錄下),如果成功備份,所有文件是一致的;
2、沒有備份參數(shù)文件,參數(shù)文件可以另外備份,沒有必要每次都備份,只需要在改變?cè)O(shè)置后備份一次;
3、如果以上命令沒有成功依次執(zhí)行,那么備份將是無效的,如連接數(shù)據(jù)庫不成功,那么肯定關(guān)閉數(shù)據(jù)庫也不成功,那么備份則無效;
4、冷備份建議下人工干預(yù)下執(zhí)行。
數(shù)據(jù)庫OS熱全備份腳本
rem script:hotbak.sql
rem creater:chenjiping
rem date:5.8.2003
rem desc:backup all database datafile in archive
--connect database
connect internal/password;
--archive
alter system archive log current;
--start
alter tablespace system begin backup;
!xcopy d:\Oracle\oradata\test\system01.dbf d:\databak/H/R;
alter tablespace system end backup;
alter tablespace rbs begin backup;
!xcopy d:\Oracle\oradata\test\rbs01.dbf d:\databak/H/R;
alter tablespace rbs end backup;
alter tablespace users begin backup;
!xcopy d:\Oracle\oradata\test\users01.dbf d:\databak/H/R;
alter tablespace users end backup;
alter tablespace tools begin backup;
!xcopy d:\Oracle\oradata\test\tools01.dbf d:\databak/H/R;
alter tablespace tools end backup;
alter tablespace indx begin backup;
!xcopy d:\Oracle\oradata\test\indx01.dbf d:\databak/H/R;
alter tablespace indx end backup;
--end
--bak control file
--binary
alter database backup controlfile to ‘d:\databak\controlbinbak.000‘;
--ascii
alter database backup controlfile to trace;
alter system archive log current;
說明:
1、熱備份必須在數(shù)據(jù)庫歸檔方式下才可以運(yùn)行;
2、以上腳本可以在數(shù)據(jù)庫運(yùn)行狀態(tài)下備份數(shù)據(jù)庫所有的數(shù)據(jù)文件(除了臨時(shí)數(shù)據(jù)文件),沒有必要備份聯(lián)機(jī)日志;
3、歸檔日志至少需要一次完整備份之后的所有日志;
4、如果以上命令沒有成功依次執(zhí)行,那么備份也是無效的,如連接數(shù)據(jù)庫不成功,那么備份則無效。
RMAN備份只講敘有恢復(fù)目錄的情況,如果沒有恢復(fù)目錄,情形大致相似。以下是RMAN的熱備份全備份的腳本:
# script:bakup.rcv
# creater:chenjiping
# date:5.8.2003
# desc:backup all database datafile in archive with rman
# connect database
connect rcvcat rman/rman@back;
connect target internal/virpure;
# start backup database
run{
allocate channel c1 type disk;
backup full tag ‘dbfull‘ format ‘d:\backup\full%u_%s_%p‘ database
include current controlfile;
sql ‘a(chǎn)lter system archive log current‘;
release channel c1;
}
# end
說明:
1、 數(shù)據(jù)庫必須運(yùn)行在歸檔模式下;
2、 RMAN將自動(dòng)備份數(shù)據(jù)文件,運(yùn)行可靠;
3、 歸檔日志另外備份處理,但至少需要保存一次備份來的日志;
4、 沒有必要用RMAN做冷備份,效果不好。
以上舉例說明了數(shù)據(jù)庫的恢復(fù)案例的測試環(huán)境與部分備份測試腳本,其它的備份腳本可以根據(jù)以上腳本演變而來或在案例中加以說明。
數(shù)據(jù)庫的自動(dòng)實(shí)例將不加以說明,這里只舉例說明媒體錯(cuò)誤或人為錯(cuò)誤造成的恢復(fù)可能。
以上包括以下案例都是在WINDOWS+Oracle816上測試驗(yàn)證的,在不同的操作系統(tǒng)與不同的數(shù)據(jù)庫版本中略有差別。
第三章. 了解與恢復(fù)相關(guān)的信息
1、 理解報(bào)警日志文件
報(bào)警日志文件一般記載了數(shù)據(jù)庫的啟動(dòng)/關(guān)閉信息,歸檔信息,備份信息,恢復(fù)信息,常見錯(cuò)誤信息,部分?jǐn)?shù)據(jù)庫修改記錄等。一般令名規(guī)則為<SID>Alrt.log或Alrt<SID>.log,如我的測試數(shù)據(jù)庫的報(bào)警日志文件的名稱為testalrt.log。
報(bào)警日志文件的路徑是根據(jù)初始化參數(shù)background_dump_dest來決定的,如在我的機(jī)器上,該參數(shù)值為 D:\Oracle\admin\test\bdump,那么,你就可以在該路徑下找到該文件。
2、 后臺(tái)進(jìn)程跟蹤文件
后臺(tái)進(jìn)程跟蹤文件的路徑與報(bào)警日志文件的路徑一致,在某些情況下,你可以通過后臺(tái)跟蹤文件的信息了解更多的需要恢復(fù)的信息。如在數(shù)據(jù)庫需要恢復(fù)的時(shí)候,報(bào)警日志文件中常有這樣的語句:
Errors in file D:\Oracle\admin\test\bdump\testDBW0.TRC:
ORA-01157: cannot identify/lock data file 1 - see DBWR trace file
通過提示的DBWR跟蹤文件,可以查詢到更詳細(xì)的信息。
3、 v$recover_file與v$recovery_log
這是兩個(gè)動(dòng)態(tài)性能視圖,可以在mount下查看,通過這兩個(gè)視圖,你可以了解詳細(xì)的需要恢復(fù)的數(shù)據(jù)文件與需要使用到的歸檔日志。
第四章. 數(shù)據(jù)庫恢復(fù)案例
4.1非歸檔模式下的備份與恢復(fù)
備份方案:采用OS冷備份
1. 連接數(shù)據(jù)庫并創(chuàng)建測試表
SQL> connect internal/password as sysdba;
Connected.
SQL> create table test(a int);
Table created
SQL> insert into test values(1);
1 row inserted
SQL> commit;
Commit complete
2. 備份數(shù)據(jù)庫
SQL> @coldbak.sql 或在DOS下 svrmgrl @coldbak.sql
3. 再插入記錄
SQL> insert into test values(2);
1 row inserted
SQL> commit;
Commit complete
SQL> select * from test;
A
-------------------
1
2
4. 關(guān)閉數(shù)據(jù)庫
SQL> shutdown immediate;
Database closed.
Database dismounted.
Oracle instance shut down.
5. 毀壞一個(gè)或多個(gè)數(shù)據(jù)文件,如刪除user01.dbf
C:\>del D:\Oracle\ORADATA\TEST\USERS01.DBF
模擬媒體毀壞。
6. 重新啟動(dòng)數(shù)據(jù)庫,會(huì)發(fā)現(xiàn)如下錯(cuò)誤
SQL> startup
Oracle instance started.
Total System Global Area 102020364 bytes
Fixed Size 70924 bytes
Variable Size 85487616 bytes
Database Buffers 16384000 bytes
Redo Buffers 77824 bytes
Database mounted.
ORA-01157: cannot identify/lock data file 3 - see DBWR trace file
ORA-01110: data file 3: ‘D:\Oracle\ORADATA\TEST\USERS01.DBF‘
在報(bào)警文件中,會(huì)有更詳細(xì)的信息
Errors in file D:\Oracle\admin\test\bdump\testDBW0.TRC:
ORA-01157: cannot identify/lock data file 3 - see DBWR trace file
ORA-01110: data file 3: ‘D:\Oracle\ORADATA\TEST\USERS01.DBF‘
ORA-27041: unable to open file
OSD-04002: unable to open file
O/S-Error: (OS 2) 系統(tǒng)找不到指定的文件。
7. 拷貝備份復(fù)原到原來位置(restore過程)
C:\>xcopy d:\database\*.* d:\Oracle\oradata\test/H/R/S
8. 打開數(shù)據(jù)庫,檢查數(shù)據(jù)
SQL> alter database open;
Database altered.
SQL> select * from test;
A
---------------------------------------
1
這里可以發(fā)現(xiàn),數(shù)據(jù)庫恢復(fù)成功,但在備份之后與崩潰之前的數(shù)據(jù)丟失了。
說明:
1、非歸檔模式下的恢復(fù)方案可選性很小,一般情況下只能有一種恢復(fù)方式,就是數(shù)據(jù)庫的冷備
份的完全恢復(fù),僅僅需要拷貝原來的備份就可以(restore),不需要recover;
2、這種情況下的恢復(fù),可以完全恢復(fù)到備份的點(diǎn)上,但是可能是丟失數(shù)據(jù)的,在備份之后與崩潰之前的數(shù)據(jù)將全部丟失;
3、不管毀壞了多少數(shù)據(jù)文件或是聯(lián)機(jī)日志或是控制文件,都可以通過這個(gè)辦法恢復(fù),因?yàn)檫@個(gè)恢復(fù)過程是Restore所有的冷備份文件,而這個(gè)備份點(diǎn)上的所有文件是一致的,與最新的數(shù)據(jù)庫沒有關(guān)系,就好比把數(shù)據(jù)庫又放到了一個(gè)以前的"點(diǎn)"上;
4、對(duì)于非歸檔模式下,最好的辦法就是采用OS的冷備份,建議不要用RMAN來作冷備份,效果不好,因?yàn)?/span>RMAN不備份聯(lián)機(jī)日志,restore不能根本解決問題;
5、如果沒有備份聯(lián)機(jī)日志,如RMAN的備份,就需要利用不完全恢復(fù)(until cancel)的方法來重新創(chuàng)建聯(lián)機(jī)日志文件。
4.2歸檔模式下丟失或損壞一個(gè)數(shù)據(jù)文件
4.2.1 OS備份方案
在歸檔方式下?lián)p壞或丟失一個(gè)數(shù)據(jù)文件,如果存在相應(yīng)的備份與該備份以來的歸檔日志,恢復(fù)還是比較簡單的,可以作到盡量少的Down機(jī)時(shí)間,并能作到數(shù)據(jù)庫的完全恢復(fù)。
1、 連接數(shù)據(jù)庫,創(chuàng)建測試表并插入記錄
SQL> connect internal/password as sysdba;
Connected.
SQL> create table test(a int) tablespace users;
Table created
SQL> insert into test values(1);
1 row inserted
SQL> commit;
Commit complete
2、 備份數(shù)據(jù)庫
SQL> @hotbak.sql 或在DOS下 svrmgrl @hotbak.sql
3、 繼續(xù)在測試表中插入記錄
SQL> insert into test values(2);
1 row inserted
SQL> commit;
Commit complete
SQL> select * from test;
A
--------------------------------------
1
2
SQL> alter system switch logfile;
System altered.
SQL> alter system switch logfile;
System altered.
4、 關(guān)閉數(shù)據(jù)庫,模擬丟失數(shù)據(jù)文件
SQL> shutdown immediate;
Database closed.
Database dismounted.
Oracle instance shut down
C:\>del D:\Oracle\ORADATA\TEST\USERS01.DBF
模擬媒體毀壞。
5、 啟動(dòng)數(shù)據(jù)庫錯(cuò)誤,脫機(jī)該數(shù)據(jù)文件:
SQL> startup
Oracle instance started.
Total System Global Area 102020364 bytes
Fixed Size 70924 bytes
Variable Size 85487616 bytes
Database Buffers 16384000 bytes
Redo Buffers 77824 bytes
Database mounted.
ORA-01157: cannot identify/lock data file 3 - see DBWR trace file
ORA-01110: data file 3: ‘D:\Oracle\ORADATA\TEST\USERS01.DBF‘
還可以查看報(bào)警文件(見上一個(gè)恢復(fù)案例)或動(dòng)態(tài)視圖v$recover_file
如SQL> select * from v$recover_file;
FILE# ONLINE ERROR CHANGE# TIME
---------- ------- ------------------ ---------- -----------
3 ONLINE 1013500 2003-05-07
脫機(jī)數(shù)據(jù)文件
SQL> alter database datafile 3 offline drop;
Database altered.
6、 打開數(shù)據(jù)庫,拷貝備份回來(restore),恢復(fù)(recover)該數(shù)據(jù)文件,并聯(lián)機(jī):
SQL> alter database open;
Database altered.
拷貝備份從備份處
copy d:\databak\ users01.dbf d:\Oracle\oradata\test;
恢復(fù)該數(shù)據(jù)文件
SQL> recover datafile 3;
ORA-00279: change 1053698 generated at
thread 1
ORA-00289: suggestion :
D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00304.ARC
ORA-00280: change 1053698 for thread 1 is in sequence #304
Specify log: {<RET>=suggested | filename | AUTO | CANCEL}
AUTO
ORA-00279: change 1053701 generated at
thread 1
ORA-00289: suggestion : D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00305.ARC
ORA-00280: change 1053701 for thread 1 is in sequence #305
ORA-00278: log file ‘D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00304.ARC‘ no longer needed for this recovery Log applied.
Media recovery complete.
恢復(fù)成功,聯(lián)機(jī)該數(shù)據(jù)文件
SQL> alter database datafile 3 online;
Database altered.
7、 檢查數(shù)據(jù)庫的數(shù)據(jù)(完全恢復(fù))
SQL> select * from test;
A
--------------------------------
1
2
說明:
1、采用熱備份,需要運(yùn)行在歸檔模式下,可以實(shí)現(xiàn)數(shù)據(jù)庫的完全恢復(fù),也就是說,從備份后到數(shù)據(jù)庫崩潰時(shí)的數(shù)據(jù)都不會(huì)丟失;
2、可以采用全備份數(shù)據(jù)庫的方式備份,對(duì)于特殊情況,也可以只備份特定的數(shù)據(jù)文件,如只備份用戶表空間(一般情況下對(duì)于某些寫特別頻繁的數(shù)據(jù)文件,可以單獨(dú)加大備份頻率);
3、如果在恢復(fù)過程中,發(fā)現(xiàn)損壞的是多個(gè)數(shù)據(jù)文件,即可以采用一個(gè)一個(gè)數(shù)據(jù)文件的恢復(fù)方法(第5步中需要對(duì)數(shù)據(jù)文件一一脫機(jī),第6步中需要對(duì)數(shù)據(jù)文件分別恢復(fù)),也可以采用整個(gè)數(shù)據(jù)庫的恢復(fù)方法;
4、如果是系統(tǒng)表空間的損壞,不能采用此方法。
4.2.2 RMAN備份方案
RMAN也可以進(jìn)行聯(lián)機(jī)備份,而且備份與恢復(fù)方法將比OS備份更簡單可靠。
1、連接數(shù)據(jù)庫,創(chuàng)建測試表并插入記錄
SQL> connect internal/password as sysdba;
Connected.
SQL> create table test(a int) tablespace users;
Table created
SQL> insert into test values(1);
1 row inserted
SQL> commit;
Commit complete
2、 備份數(shù)據(jù)庫表空間users
C:\>rman
Recovery Manager: Release 8.1.6.0.0 - Production
RMAN> connect rcvcat rman/rman@back
RMAN-06008: connected to recovery catalog database
RMAN> connect target internal/virpure
RMAN-06005: connected to target database: TEST (DBID=1788174720)
RMAN> run{
2> allocate channel c1 type disk;
3> backup tag ‘tsuser‘ format ‘d:\backup\tsuser_%u_%s_%p‘
4> tablespace users;
5> release channel c1;
6> }
RMAN-03022: compiling command: allocate
RMAN-03023: executing command: allocate
RMAN-08030: allocated channel: c1
RMAN-08500: channel c1: sid=16 devtype=DISK
RMAN-03022: compiling command: backup
RMAN-03025: performing implicit partial resync of recovery catalog
RMAN-03023: executing command: partial resync
RMAN-08003: starting partial resync of recovery catalog
RMAN-08005: partial resync complete
RMAN-03023: executing command: backup
RMAN-08008: channel c1: starting full datafile backupset
RMAN-08502: set_count=5 set_stamp=494177612 creation_time=
RMAN-08010: channel c1: specifying datafile(s) in backupset
RMAN-08522: input datafile fno=00003 name=D:\Oracle\ORADATA\TEST\USER01.DBF
RMAN-08013: channel c1: piece 1 created
RMAN-08503: piece handle=D:\BACKUP\TSUSER_05EN93AC_5_1 comment=NONE
RMAN-08525: backup set complete, elapsed time:
RMAN-03023: executing command: partial resync
RMAN-08003: starting partial resync of recovery catalog
RMAN-08005: partial resync complete
RMAN-03022: compiling command: release
RMAN-03023: executing command: release
RMAN-08031: released channel: c1
RMAN>
3、 繼續(xù)在測試表中插入記錄
SQL> insert into test values(2);
1 row inserted
SQL> commit;
Commit complete
SQL> select * from test;
A
---------------------------------------
1
2
SQL> alter system switch logfile;
System altered.
SQL>r
1* alter system switch logfile;
System altered.
4、 關(guān)閉數(shù)據(jù)庫,模擬丟失數(shù)據(jù)文件
SQL> shutdown immediate;
Database closed.
Database dismounted.
Oracle instance shut down
C:\>del D:\Oracle\ORADATA\TEST\USER01.DBF
5、 啟動(dòng)數(shù)據(jù)庫,檢查錯(cuò)誤
SQL> startup
Oracle instance started.
Total System Global Area 102020364 bytes
Fixed Size 70924 bytes
Variable Size 85487616 bytes
Database Buffers 16384000 bytes
Redo Buffers 77824 bytes
Database mounted.
ORA-01157: cannot identify/lock data file 3 - see DBWR trace file
ORA-01110: data file 3: ‘D:\Oracle\ORADATA\TEST\USER01.DBF‘
6、 先打開數(shù)據(jù)庫
SQL> alter database datafile 3 offline drop;
Database altered.
SQL> alter database open;
Database altered.
7、 恢復(fù)該表空間
恢復(fù)腳本可以是恢復(fù)單個(gè)數(shù)據(jù)文件
run{
allocate channel c1 type disk;
restore datafile 3;
recover datafile 3;
sql ‘a(chǎn)lter database datafile 3 online‘;
release channel c1;
}
也可以是,恢復(fù)表空間
run{
allocate channel c1 type disk;
restore tablespace users;
recover tablespace users;
sql ‘a(chǎn)lter database datafile 3 online‘;
release channel c1;
}
過程如下:
C:\>rman
Recovery Manager: Release 8.1.6.0.0 - Production
RMAN> connect rcvcat rman/rman@back
RMAN-06008: connected to recovery catalog database
RMAN> connect target internal/virpure
RMAN-06005: connected to target database: TEST (DBID=1788174720)
RMAN> run{
2> allocate channel c1 type disk;
3> restore datafile 3;
4> recover datafile 3;
5> sql ‘a(chǎn)lter database datafile 3 online‘;
6> release channel c1;
7> }
//輸出內(nèi)容冗長,省略--編者
RMAN>
8、 檢查數(shù)據(jù)是否完整
SQL> alter database open;
Database altered.
SQL> select * from test;
A
---------------------------------------
1
2
說明:
1、RMAN也可以實(shí)現(xiàn)單個(gè)表空間或數(shù)據(jù)文件的恢復(fù),恢復(fù)過程可以在mount下或open方式下,如果在open方式下恢復(fù),可以減少down機(jī)時(shí)間;
2、如果損壞的是一個(gè)數(shù)據(jù)文件,建議offline并在open方式下恢復(fù);
3、這里可以看到,RMAN進(jìn)行數(shù)據(jù)文件與表空間恢復(fù)的時(shí)候,代碼都比較簡單,而且能保證備份與恢復(fù)的可靠性,所以建議采用RMAN的備份與恢復(fù).
4.3丟失多個(gè)數(shù)據(jù)文件,實(shí)現(xiàn)整個(gè)數(shù)據(jù)庫的恢復(fù).
4.3.1 OS備份方案
OS備份歸檔模式下?lián)p壞(丟失)多個(gè)數(shù)據(jù)文件,進(jìn)行整個(gè)數(shù)據(jù)庫的恢復(fù)
1、 連接數(shù)據(jù)庫,創(chuàng)建測試表并插入記錄
SQL> connect internal/password as sysdba;
Connected.
SQL> create table test(a int);
Table created
SQL> insert into test values(1);
1 row inserted
SQL> commit;
Commit complete
2、 備份數(shù)據(jù)庫,備份除臨時(shí)數(shù)據(jù)文件后的所數(shù)據(jù)文件
SQL> @hotbak.sql 或在DOS下 svrmgrl @hotbak.sql
3、 繼續(xù)在測試表中插入記錄
SQL> insert into test values(2);
1 row inserted
SQL> commit;
Commit complete
SQL> select * from test;
A
---------------------------------------
1
2
SQL> alter system switch logfile;
System altered.
SQL> alter system switch logfile;
System altered.
4、 關(guān)閉數(shù)據(jù)庫,模擬丟失數(shù)據(jù)文件
SQL> shutdown immediate;
Database closed.
Database dismounted.
Oracle instance shut down
C:\>del D:\Oracle\ORADATA\TEST\SYSTEM01.DBF
C:\>del D:\Oracle\ORADATA\TEST\INDX01.DBF
C:\>del D:\Oracle\ORADATA\TEST\TOOLS01.DBF
C:\>del D:\Oracle\ORADATA\TEST\RBS01.DBF
模擬媒體毀壞(這里刪除多個(gè)數(shù)據(jù)文件)
5、 啟動(dòng)數(shù)據(jù)庫,檢查錯(cuò)誤
SQL> STARTUP
Oracle instance started.
Total System Global Area 102020364 bytes
Fixed Size 70924 bytes
Variable Size 85487616 bytes
Database Buffers 16384000 bytes
Redo Buffers 77824 bytes
Database mounted.
ORA-01157: cannot identify/lock data file 1 - see DBWR trace file
ORA-01110: data file 1: ‘D:\Oracle\ORADATA\TEST\SYSTEM01.DBF‘
詳細(xì)信息可以查看報(bào)警文件
ORA-1157 signalled during: ALTER DATABASE OPEN...
Thu May 08
Errors in file D:\Oracle\admin\test\bdump\testDBW0.TRC:
ORA-01157: cannot identify/lock data file 1 - see DBWR trace file
ORA-01110: data file 1: ‘D:\Oracle\ORADATA\TEST\SYSTEM01.DBF‘
ORA-27041: unable to open file
OSD-04002: unable to open file
O/S-Error: (OS 2) 系統(tǒng)找不到指定的文件。
Thu May 08
Errors in file D:\Oracle\admin\test\bdump\testDBW0.TRC:
ORA-01157: cannot identify/lock data file 2 - see DBWR trace file
ORA-01110: data file 2: ‘D:\Oracle\ORADATA\TEST\RBS01.DBF‘
ORA-27041: unable to open file
OSD-04002: unable to open file
O/S-Error: (OS 2) 系統(tǒng)找不到指定的文件。
Thu May 08
Errors in file D:\Oracle\admin\test\bdump\testDBW0.TRC:
ORA-01157: cannot identify/lock data file 5 - see DBWR trace file
ORA-01110: data file 5: ‘D:\Oracle\ORADATA\TEST\TOOLS01.DBF‘
ORA-27041: unable to open file
OSD-04002: unable to open file
O/S-Error: (OS 2) 系統(tǒng)找不到指定的文件。
Thu May 08
Errors in file D:\Oracle\admin\test\bdump\testDBW0.TRC:
ORA-01157: cannot identify/lock data file 6 - see DBWR trace file
ORA-01110: data file 6: ‘D:\Oracle\ORADATA\TEST\INDX01.DBF‘
ORA-27041: unable to open file
OSD-04002: unable to open file
O/S-Error: (OS 2) 系統(tǒng)找不到指定的文件。
通過查詢v$recover_file可以看到
SQL> select * from v$recover_file;
FILE# ONLINE ERROR CHANGE# TIME
---------- ------- ------------------ ---------- -----------
1 ONLINE FILE NOT FOUND 0
2 ONLINE FILE NOT FOUND 0
5 ONLINE FILE NOT FOUND 0
6 ONLINE FILE NOT FOUND 0
有四個(gè)數(shù)據(jù)文件需要恢復(fù)
6、 拷貝備份回到原地點(diǎn)(restore),開始恢復(fù)數(shù)據(jù)庫(recover)
restore過程:
C:\>copy D:\DATABAK\SYSTEM01.DBF D:\Oracle\ORADATA\TEST\
C:\>copy D:\DATABAK\TEST\INDX01.DBF D:\Oracle\ORADATA\TEST\
C:\>copy D:\DATABAK\TEST\TOOLS01.DBF D:\Oracle\ORADATA\TEST\
C:\>copy D:\DATABAK\TEST\RBS01.DBF.DBF D:\Oracle\ORADATA\TEST\
Recover過程:
SQL> recover database;
ORA-00279: change 1073849 generated at
ORA-00289: suggestion : D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00311.ARC
ORA-00280: change 1073849 for thread 1 is in sequence #311
Specify log: {<RET>=suggested | filename | AUTO | CANCEL}
auto
ORA-00279: change 1073856 generated at
ORA-00289: suggestion : D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00312.ARC
ORA-00280: change 1073856 for thread 1 is in sequence #312
ORA-00278: log file ‘D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00311.ARC‘ no
longer needed for this recovery
ORA-00279: change 1073858 generated at
ORA-00289: suggestion : D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00313.ARC
ORA-00280: change 1073858 for thread 1 is in sequence #313
ORA-00278: log file ‘D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00312.ARC‘ no
longer needed for this recovery
ORA-00279: change 1073870 generated at
ORA-00289: suggestion : D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00314.ARC
ORA-00280: change 1073870 for thread 1 is in sequence #314
ORA-00278: log file ‘D:\Oracle\ORADATA\TEST\ARCHIVE\TESTT001S00313.ARC‘ no
longer needed for this recovery
Log applied.
Media recovery complete.
7、 打開數(shù)據(jù)庫,檢查數(shù)據(jù)庫的數(shù)據(jù)(完全恢復(fù))
SQL> alter database open;
Database altered.
SQL> select * from test;
A
---------------------------------------
1
2
說明:
1、只要有備份與歸檔存在,就可以實(shí)現(xiàn)數(shù)據(jù)庫的完全恢復(fù)(不丟失數(shù)據(jù));
2、適合于丟失大量數(shù)據(jù)文件,或包含系統(tǒng)數(shù)據(jù)文件在內(nèi)的數(shù)據(jù)庫的恢復(fù);
3、恢復(fù)過程在mount下進(jìn)行,如果恢復(fù)成功,再打開數(shù)據(jù)庫,down機(jī)時(shí)間可能比較長一些。
4.3.2 RMAN備份方案
RMAN備份歸檔模式下?lián)p壞(丟失)多個(gè)數(shù)據(jù)文件,進(jìn)行整個(gè)數(shù)據(jù)庫的恢復(fù)
1、連接數(shù)據(jù)庫,創(chuàng)建測試表并插入記錄
SQL> connect internal/password as sysdba;
Connected.
SQL> create table test(a int);
Table created
SQL> insert into test values(1);
1 row inserted
SQL> commit;
Commit complete
2、備份數(shù)據(jù)庫
DOS下 C:>\ rman cmdfile=bakup.rcv msglog=backup.log;
以下是backup.log內(nèi)容。
Recovery Manager: Release 8.1.6.0.0 - Production
RMAN> # script:bakup.rcv
2> # creater:chenjiping
3> # date:5.8.2003
4> # desc:backup all database datafile in archive with rman
5>
6> #connect database
7> connect rcvcat rman/rman@back;
8> connect target internal/virpure;
9>
10> #start backup database
11> run{
12> allocate channel c1 type disk;
13> backup full tag ‘dbfull‘ format ‘d:\backup\full%u_%s_%p‘ database
14> include current controlfile;
15> sql ‘a(chǎn)lter system archive log current‘;
16> release channel c1;
17> }
18> #end
19>
RMAN-06008: connected to recovery catalog database
RMAN-06005: connected to target database: TEST (DBID=1788174720)
RMAN-03022: compiling command: allocate
RMAN-03023: executing command: allocate
RMAN-08030: allocated channel: c1
RMAN-08500: channel c1: sid=15 devtype=DISK
RMAN-03022: compiling command: backup
RMAN-03023: executing command: backup
RMAN-08008: channel c1: starting full datafile backupset
RMAN-08502: set_count=4 set_stamp=494074368 creation_time=
RMAN-08010: channel c1: specifying datafile(s) in backupset
RMAN-08522: input datafile fno=00002 name=D:\Oracle\ORADATA\TEST\RBS01.DBF
RMAN-08522: input datafile fno=00001 name=D:\Oracle\ORADATA\TEST\SYSTEM01.DBF
RMAN-08011: including current controlfile in backupset
RMAN-08522: input datafile fno=00005 name=D:\Oracle\ORADATA\TEST\TOOLS01.DBF
RMAN-08522: input datafile fno=00004 name=D:\Oracle\ORADATA\TEST\TEMP01.DBF
RMAN-08522: input datafile fno=00006 name=D:\Oracle\ORADATA\TEST\INDX01.DBF
RMAN-08522: input datafile fno=00003 name=D:\Oracle\ORADATA\TEST\USER01.DBF
RMAN-08013: channel c1: piece 1 created
RMAN-08503: piece handle=D:\BACKUP\FULL04EN5UG0_4_1 comment=NONE
RMAN-08525: backup set complete, elapsed time:
RMAN-03023: executing command: partial resync
RMAN-08003: starting partial resync of recovery catalog
RMAN-08005: partial resync complete
RMAN-03022: compiling command: sql
RMAN-06162: sql statement: alter system archive log current
RMAN-03023: executing command: sql
RMAN-03022: compiling command: release
RMAN-03023: executing command: release
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