
通常見到的還原操作,都是將所有的表空間和數據還原到相同的一個時間點上,無論是否是故障恢復點。而TSPITR則是以表空間為粒度單元,單獨將某個表空間內容還原到一個特定可恢復時間點上。 舉一個例子:一個Oracle數據庫運行在歸檔模式下,在夜間22點保留一份
通常見到的還原操作,都是將所有的表空間和數據還原到相同的一個時間點上,無論是否是故障恢復點。而TSPITR則是以表空間為粒度單元,單獨將某個表空間內容還原到一個特定可恢復時間點上。
舉一個例子:一個Oracle數據庫運行在歸檔模式下,在夜間22點保留一份完全備份。早上8點時候,某個特定表空間上數據表(單個表獨占表空間)發生一個誤操作,數據損壞。要求在不傷害其他數據表數據的情況下,將表空間數據恢復到早上5點。這樣部分數據恢復的場景,就是TSPITR的典型應用。在實際場景中,常常希望恢復部分的數據到過去時間點上。
TSPITR目前最方便的方法是使用RMAN進行自動的恢復。
其使用前提為兩個:
1. 必須存在相應【本文來自鴻網互聯 (http://www.68idc.cn)】的備份集合
2. 表空間對象是子包含的,也就是其他表空間中不包括與這個表空間對象相關的對象數據(互相獨立)
恢復步驟和原理如下:
RMAN三個對象集合:catalog、target和auxiliary。其中auxiliary就是用于輔助target各種備份還原要求的操作數據庫。這個庫在TSPITR中扮演臨時數據還原作用的;
首先完成數據檢查工作,確定備份集合和表空間完整性;
當前時間是T1,如果需要將數據還原為T0。使用RMAN提取備份數據集合,還原到auxiliary上形成一個新的實例數據庫。選擇性應用歸檔日志序列,還原auxiliary到TO時間點;
使用expdp工具從auxiliary中導出目標表空間為dump對象。注意:還原auxiliary并不是100%重建target,而是選擇系統運行表空間和目標表空間;
在target數據庫中刪除原表空間。使用impdp工具導入dump文件進入target數據庫;
清理環境,將創建的auxiliary數據庫刪除。
這種系列操作,如果使用RMAN命令系列是可以逐步完成的。自動化RMAN的TSPITR操作也是對這個過程的完全自動化運行。
下面通過實驗來進行演示操作:
--創建測試用戶zlm并賦予權限
SQL> create user zlm identified by zlm;
User created.
SQL> grant dba to zlm;
Grant succeeded.
--創建測試表空間tspitr
SQL> create tablespace tspitr datafile '/data/oradata/ora10g/tspitr01.dbf' size 100m autoextend off extent management local uniform size 1m segment space management auto;
Tablespace created.
--修改用戶zlm缺省表空間為tspitr
SQL> alter user zlm default tablespace tspitr;
User altered.
SQL> show user
USER is ""
SQL> conn zlm/zlm@ora10g213
Connected.
SQL> !
--創建一個RMAN備份集
[oracle@bak ~]$ rman target /
Recovery Manager: Release 10.2.0.1.0 - Production on Fri Dec 26 16:44:00 2014
Copyright (c) 1982, 2005, Oracle. All rights reserved.
connected to target database: ORA10G (DBID=4175411955)
RMAN> backup as compressed backupset database format '/u01/orabackup/backupsets/full_ora10g_%U' plus archive log format '/u01/orabackup/backupsets/arc_ora10g_%U' delete all input;
Starting backup at 26-DEC-14
current log archived
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=138 devtype=DISK
channel ORA_DISK_1: starting compressed archive log backupset
channel ORA_DISK_1: specifying archive log(s) in backup set
input archive log thread=1 sequence=30 recid=30 stamp=867343597
channel ORA_DISK_1: starting piece 1 at 26-DEC-14
channel ORA_DISK_1: finished piece 1 at 26-DEC-14
piece handle=/u01/orabackup/backupsets/arc_ora10g_13pr577g_1_1 tag=TAG20141226T164639 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:04
channel ORA_DISK_1: deleting archive log(s)
archive log filename=/oracle/flash_recovery_area/ORA10G/archivelog/2014_12_26/o1_mf_1_30_b9t83f1s_.arc recid=30 stamp=867343597
Finished backup at 26-DEC-14
Starting backup at 26-DEC-14
using channel ORA_DISK_1
channel ORA_DISK_1: starting compressed full datafile backupset
channel ORA_DISK_1: specifying datafile(s) in backupset
input datafile fno=00001 name=/data/oradata/ora10g/system01.dbf
input datafile fno=00003 name=/data/oradata/ora10g/sysaux01.dbf
input datafile fno=00002 name=/data/oradata/ora10g/undotbs01.dbf
input datafile fno=00005 name=/data/oradata/ora10g/example01.dbf
input datafile fno=00006 name=/data/oradata/ora10g/tspitr01.dbf
input datafile fno=00004 name=/data/oradata/ora10g/users01.dbf
channel ORA_DISK_1: starting piece 1 at 26-DEC-14
channel ORA_DISK_1: finished piece 1 at 26-DEC-14
piece handle=/u01/orabackup/backupsets/full_ora10g_14pr577l_1_1 tag=TAG20141226T164644 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:02:47
Finished backup at 26-DEC-14
Starting backup at 26-DEC-14
current log archived
using channel ORA_DISK_1
channel ORA_DISK_1: starting compressed archive log backupset
channel ORA_DISK_1: specifying archive log(s) in backup set
input archive log thread=1 sequence=31 recid=31 stamp=867343772
channel ORA_DISK_1: starting piece 1 at 26-DEC-14
channel ORA_DISK_1: finished piece 1 at 26-DEC-14
piece handle=/u01/orabackup/backupsets/arc_ora10g_15pr57ct_1_1 tag=TAG20141226T164933 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
channel ORA_DISK_1: deleting archive log(s)
archive log filename=/oracle/flash_recovery_area/ORA10G/archivelog/2014_12_26/o1_mf_1_31_b9t88wnv_.arc recid=31 stamp=867343772
Finished backup at 26-DEC-14
Starting Control File and SPFILE Autobackup at 26-DEC-14
piece handle=/u01/orabackup/backupsets/ora10g-c-4175411955-20141226-05.ctl comment=NONE
Finished Control File and SPFILE Autobackup at 26-DEC-14
RMAN> exit
Recovery Manager complete.
--連接到測試用戶zlm查看當前日志
[oracle@bak ~]$ sqlplus /nolog
SQL*Plus: Release 10.2.0.1.0 - Production on Fri Dec 26 16:50:46 2014
Copyright (c) 1982, 2005, Oracle. All rights reserved.
Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
SQL> conn zlm/zlm@ora10g213
Connected.
SQL> select sequence#,status from v$log;
SEQUENCE# STATUS
---------- ----------------
32 CURRENT
30 INACTIVE
31 ACTIVE
--創建測試表t1,并切換若干次日志
SQL> create table t1 as select * from dba_objects;
Table created.
SQL> alter system switch logfile;
System altered.
SQL> select sequence#,status from v$log;
SEQUENCE# STATUS
---------- ----------------
32 ACTIVE
33 CURRENT
31 ACTIVE
SQL> alter system switch logfile;
System altered.
SQL> select sequence#,status from v$log;
SEQUENCE# STATUS
---------- ----------------
32 ACTIVE
33 ACTIVE
34 CURRENT --此時仍然時候數據的
SQL> select count(*) from t1;
COUNT(*)
----------
50382
--對表進行truancate操作,模擬誤操作
SQL> truncate table t1;
Table truncated.
SQL> select count(*) from t1;
COUNT(*)
----------
0
SQL> alter system switch logfile;
System altered.
SQL> select sequence#,status from v$log;
SEQUENCE# STATUS
---------- ----------------
35 CURRENT --truncate之后又切換了一次日志,當前日志為35
33 ACTIVE
34 ACTIVE
SQL> !
創建表的時候,logseq是32,之后切換了一次日志,到33,此時的表中仍然是有數據的,但是truncate操作后表中的數據就沒有了,這個動作基本就是在logseq 34的時候發生的,truncate完以后又切了日志,到了35,我們實驗的目的就是要把表空間恢復到logseq=34這個時間點(Time In Point)。根據剛才說的那個例子,就是到故障點8點以前的某個數據未丟失的時間點(5點)
--創建一個auxiliary目錄(必要步驟)
[oracle@bak ~]$ mkdir /u01/aux
[oracle@bak ~]$ rman target /
Recovery Manager: Release 10.2.0.1.0 - Production on Fri Dec 26 16:54:36 2014
Copyright (c) 1982, 2005, Oracle. All rights reserved.
connected to target database: ORA10G (DBID=4175411955)
auxiliary目標目錄中會在之后的RMAN腳本執行過程中,生成一些系統恢復需要的文件,等RMAN恢復完后會展示一下這個目錄的結構。
--最關鍵的來了,用RMAN命令進行TSPITR恢復到故障點之前的某個時刻
RMAN> recover tablespace tspitr until logseq 33 auxiliary destination '/u01/aux';
Starting recover at 26-DEC-14
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=159 devtype=DISK
RMAN-05026: WARNING: presuming following set of tablespaces applies to specified point in time
List of tablespaces expected to have UNDO segments --有undo段的表空間列表
tablespace SYSTEM
tablespace UNDOTBS1
Creating automatic instance, with SID='xvBc' --創建一個自動化實例,隨機SID為xvBc
initialization parameters used for automatic instance: --為自動化實例分配的參數
db_name=ORA10G
compatible=10.2.0.1.0
db_block_size=8192
db_files=200
db_unique_name=tspitr_ORA10G_xvBc
large_pool_size=1M
shared_pool_size=110M
#No auxiliary parameter file used
db_create_file_dest=/u01/aux --之前創建的auxiliary目錄
control_files=/u01/aux/cntrl_tspitr_ORA10G_xvBc.f --控制文件的位置
starting up automatic instance ORA10G --啟動自動化實例
Oracle instance started
Total System Global Area 201326592 bytes
Fixed Size 1218508 bytes
Variable Size 146802740 bytes
Database Buffers 50331648 bytes
Redo Buffers 2973696 bytes
Automatic instance created
contents of Memory Script: --第1個內存腳本內容
{
# set the until clause
set until logseq 33 thread 1; --指定的需要恢復到的logseq
# restore the controlfile
restore clone controlfile;
# mount the controlfile
sql clone 'alter database mount clone database';
# archive current online log for tspitr to a resent until time
sql 'alter system archive log current';
# avoid unnecessary autobackups for structural changes during TSPITR
sql 'begin dbms_backup_restore.AutoBackupFlag(FALSE); end;';
}
executing Memory Script
executing command: SET until clause
Starting restore at 26-DEC-14
allocated channel: ORA_AUX_DISK_1
channel ORA_AUX_DISK_1: sid=36 devtype=DISK
channel ORA_AUX_DISK_1: starting datafile backupset restore
channel ORA_AUX_DISK_1: restoring control file
channel ORA_AUX_DISK_1: reading from backup piece /u01/orabackup/backupsets/ora10g-c-4175411955-20141226-05.ctl
channel ORA_AUX_DISK_1: restored backup piece 1
piece handle=/u01/orabackup/backupsets/ora10g-c-4175411955-20141226-05.ctl tag=TAG20141226T164935
channel ORA_AUX_DISK_1: restore complete, elapsed time: 00:00:02
output filename=/u01/aux/cntrl_tspitr_ORA10G_xvBc.f
Finished restore at 26-DEC-14
sql statement: alter database mount clone database
sql statement: alter system archive log current
sql statement: begin dbms_backup_restore.AutoBackupFlag(FALSE); end;
released channel: ORA_DISK_1
released channel: ORA_AUX_DISK_1
contents of Memory Script: --第2個內存腳本內容
{
# generated tablespace point-in-time recovery script
# set the until clause
set until logseq 33 thread 1;
plsql <<<-- tspitr_2
declare
sqlstatement varchar2(512);
offline_not_needed exception;
pragma exception_init(offline_not_needed, -01539);
begin
sqlstatement := 'alter tablespace '|| 'TSPITR' ||' offline for recover';
krmicd.writeMsg(6162, sqlstatement);
krmicd.execSql(sqlstatement);
exception
when offline_not_needed then
null;
end; >>>;
# set an omf destination filename for restore
set newname for clone datafile 1 to new;
# set an omf destination filename for restore
set newname for clone datafile 2 to new;
# set an omf destination tempfile
set newname for clone tempfile 2 to new;
# set a destination filename for restore
set newname for datafile 6 to
"/data/oradata/ora10g/tspitr01.dbf";
# rename all tempfiles
switch clone tempfile all;
# restore the tablespaces in the recovery set plus the auxilliary tablespaces
restore clone datafile 1, 2, 6;
switch clone datafile all;
#online the datafiles restored or flipped
sql clone "alter database datafile 1 online";
#online the datafiles restored or flipped
sql clone "alter database datafile 2 online";
#online the datafiles restored or flipped
sql clone "alter database datafile 6 online";
# make the controlfile point at the restored datafiles, then recover them
recover clone database tablespace "TSPITR", "SYSTEM", "UNDOTBS1" delete archivelog;
alter clone database open resetlogs;
# PLUG HERE the creation of a temporary tablespace if export fails due to lack
# of temporary space.
# For example in Unix these two lines would do that:
#sql clone "create tablespace aux_tspitr_tmp
# datafile ''/tmp/aux_tspitr_tmp.dbf'' size 500K";
}
executing Memory Script
executing command: SET until clause
sql statement: alter tablespace TSPITR offline for recover
executing command: SET NEWNAME
executing command: SET NEWNAME
executing command: SET NEWNAME
executing command: SET NEWNAME
renamed temporary file 2 to /u01/aux/TSPITR_ORA10G_XVBC/datafile/o1_mf_temp_%u_.tmp in control file
Starting restore at 26-DEC-14
allocated channel: ORA_AUX_DISK_1
channel ORA_AUX_DISK_1: sid=39 devtype=DISK
channel ORA_AUX_DISK_1: starting datafile backupset restore
channel ORA_AUX_DISK_1: specifying datafile(s) to restore from backup set
restoring datafile 00001 to /u01/aux/TSPITR_ORA10G_XVBC/datafile/o1_mf_system_%u_.dbf
restoring datafile 00002 to /u01/aux/TSPITR_ORA10G_XVBC/datafile/o1_mf_undotbs1_%u_.dbf
restoring datafile 00006 to /data/oradata/ora10g/tspitr01.dbf
channel ORA_AUX_DISK_1: reading from backup piece /u01/orabackup/backupsets/full_ora10g_14pr577l_1_1
channel ORA_AUX_DISK_1: restored backup piece 1
piece handle=/u01/orabackup/backupsets/full_ora10g_14pr577l_1_1 tag=TAG20141226T164644
channel ORA_AUX_DISK_1: restore complete, elapsed time: 00:02:26
Finished restore at 26-DEC-14
datafile 1 switched to datafile copy
input datafile copy recid=4 stamp=867344300 filename=/u01/aux/TSPITR_ORA10G_XVBC/datafile/o1_mf_system_b9t8nvw3_.dbf
datafile 2 switched to datafile copy
input datafile copy recid=5 stamp=867344300 filename=/u01/aux/TSPITR_ORA10G_XVBC/datafile/o1_mf_undotbs1_b9t8nvx5_.dbf
sql statement: alter database datafile 1 online
sql statement: alter database datafile 2 online
sql statement: alter database datafile 6 online
Starting recover at 26-DEC-14
using channel ORA_AUX_DISK_1
starting media recovery
archive log thread 1 sequence 32 is already on disk as file /oracle/flash_recovery_area/ORA10G/archivelog/2014_12_26/o1_mf_1_32_b9t8dkr8_.arc
channel ORA_AUX_DISK_1: starting archive log restore to default destination
channel ORA_AUX_DISK_1: restoring archive log
archive log thread=1 sequence=31
channel ORA_AUX_DISK_1: reading from backup piece /u01/orabackup/backupsets/arc_ora10g_15pr57ct_1_1
channel ORA_AUX_DISK_1: restored backup piece 1
piece handle=/u01/orabackup/backupsets/arc_ora10g_15pr57ct_1_1 tag=TAG20141226T164933
channel ORA_AUX_DISK_1: restore complete, elapsed time: 00:00:03
archive log filename=/u01/app/oracle/product/10.2.0/db_1/dbs/arch1_31_860802036.dbf thread=1 sequence=31
channel clone_default: deleting archive log(s)
archive log filename=/u01/app/oracle/product/10.2.0/db_1/dbs/arch1_31_860802036.dbf recid=32 stamp=867344306
archive log filename=/oracle/flash_recovery_area/ORA10G/archivelog/2014_12_26/o1_mf_1_32_b9t8dkr8_.arc thread=1 sequence=32
media recovery complete, elapsed time: 00:00:05
Finished recover at 26-DEC-14
database opened
contents of Memory Script: --第3個內存腳本(邏輯導入導出)
{
# export the tablespaces in the recovery set
host 'exp userid =\"/@\(DESCRIPTION=\(ADDRESS=\(PROTOCOL=beq\)\(PROGRAM=/u01/app/oracle/product/10.2.0/db_1/bin/oracle\)\(ARGV0=oraclexvBc\)\(ARGS=^'\(DESCRIPTION=\(LOCAL=YES\)\(ADDRESS=\(PROTOCOL=beq\)\)\)^'\)\(ENVS=^'ORACLE_SID=xvBc^'\)\)\(CONNECT_DATA=\(SID=xvBc\)\)\)
as sysdba\" point_in_time_recover=y tablespaces=
TSPITR file=
tspitr_a.dmp';
# shutdown clone before import
shutdown clone immediate
# import the tablespaces in the recovery set
host 'imp userid =\"/@ as sysdba\" point_in_time_recover=y file=
tspitr_a.dmp';
# online/offline the tablespace imported
sql "alter tablespace TSPITR online";
sql "alter tablespace TSPITR offline";
# enable autobackups in case user does open resetlogs from RMAN after TSPITR
sql 'begin dbms_backup_restore.AutoBackupFlag(TRUE); end;';
}
executing Memory Script
Export: Release 10.2.0.1.0 - Production on Fri Dec 26 16:58:55 2014
Copyright (c) 1982, 2005, Oracle. All rights reserved.
Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
Export done in US7ASCII character set and AL16UTF16 NCHAR character set
server uses ZHS16GBK character set (possible charset conversion)
Note: table data (rows) will not be exported
About to export Tablespace Point-in-time Recovery objects... --執行導出TSPITR對象
For tablespace TSPITR ...
. exporting cluster definitions
. exporting table definitions
. . exporting table T
. . exporting table T1 --導出誤刪除的測試表
. exporting referential integrity constraints
. exporting triggers
. end point-in-time recovery
Export terminated successfully without warnings. --導出完成無報錯
host command complete
database closed
database dismounted
Oracle instance shut down
Import: Release 10.2.0.1.0 - Production on Fri Dec 26 16:59:17 2014
Copyright (c) 1982, 2005, Oracle. All rights reserved.
Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
Export file created by EXPORT:V10.02.01 via conventional path
About to import Tablespace Point-in-time Recovery objects...
import done in US7ASCII character set and AL16UTF16 NCHAR character set
import server uses ZHS16GBK character set (possible charset conversion)
. importing SYS's objects into SYS
. importing ZLM's objects into ZLM
. . importing table "T"
. . importing table "T1" --導入誤刪除的測試表
. importing SYS's objects into SYS
Import terminated successfully without warnings.
host command complete
sql statement: alter tablespace TSPITR online
sql statement: alter tablespace TSPITR offline --最后一步操作是把要恢復的表空間offline的
sql statement: begin dbms_backup_restore.AutoBackupFlag(TRUE); end;
Removing automatic instance --刪除自動化實例以及相關文件
Automatic instance removed
auxiliary instance file /u01/aux/cntrl_tspitr_ORA10G_xvBc.f deleted
auxiliary instance file /u01/aux/TSPITR_ORA10G_XVBC/datafile/o1_mf_system_b9t8nvw3_.dbf deleted
auxiliary instance file /u01/aux/TSPITR_ORA10G_XVBC/datafile/o1_mf_undotbs1_b9t8nvx5_.dbf deleted
auxiliary instance file /u01/aux/TSPITR_ORA10G_XVBC/datafile/o1_mf_temp_b9t8t370_.tmp deleted
auxiliary instance file /u01/aux/TSPITR_ORA10G_XVBC/onlinelog/o1_mf_1_b9t8srrv_.log deleted
auxiliary instance file /u01/aux/TSPITR_ORA10G_XVBC/onlinelog/o1_mf_2_b9t8svp8_.log deleted
auxiliary instance file /u01/aux/TSPITR_ORA10G_XVBC/onlinelog/o1_mf_3_b9t8sy5v_.log deleted
Finished recover at 26-DEC-14
RMAN> exit
Recovery Manager complete.
[oracle@bak ~]$ sqlplus /nolog
SQL*Plus: Release 10.2.0.1.0 - Production on Fri Dec 26 17:03:26 2014
Copyright (c) 1982, 2005, Oracle. All rights reserved.
SQL> conn zlm/zlm@ora10g213
Connected.
SQL> select count(*) from t1;
select count(*) from t1
*
ERROR at line 1:
ORA-00376: file 6 cannot be read at this time
ORA-01110: data file 6: '/data/oradata/ora10g/tspitr01.dbf'
無法打開恢復的6號文件,由于最后的操作是把該表空間offline的
SQL> select status from dba_tablespaces where tablespace_name='TSPITR';
STATUS
---------
OFFLINE
--重新將tspitr表空間online
SQL> alter tablespace tspitr online;
Tablespace altered.
SQL> select count(*) from t1;
COUNT(*)
----------
50382
之前誤刪除的測試表T1的數據又回來了。
最后來看一下auxiliary目錄結構
[oracle@bak admin]$ cd /u01/aux
[oracle@bak aux]$ ll
total 4
drwxr-x--- 4 oracle oinstall 4096 Dec 26 16:55 TSPITR_ORA10G_XVBC
[oracle@bak aux]$ cd TSPITR_ORA10G_XVBC/
[oracle@bak TSPITR_ORA10G_XVBC]$ ll -lrth
total 8.0K
drwxr-x--- 2 oracle oinstall 4.0K Dec 26 16:59 onlinelog
drwxr-x--- 2 oracle oinstall 4.0K Dec 26 16:59 datafile
[oracle@bak TSPITR_ORA10G_XVBC]$ cd onlinelog/
[oracle@bak onlinelog]$ ll
total 0
[oracle@bak onlinelog]$ cd ..
[oracle@bak TSPITR_ORA10G_XVBC]$ cd datafile
[oracle@bak datafile]$ ll
total 0
[oracle@bak datafile]$
雖然在中間過程創建了相關目錄和文件,恢復結束以后,只留下了目錄結構,文件都被自動刪除了
總結:
其實TSPITR方式是對整個表空間的恢復,無論該表空間上有多少張表或對象,只要是自包含的表空間,就可以使用這種方法來進行恢復。但是也有局限性,比方說要恢復的表空間上有許多表,也是自包含的表空間,由于某張表的誤刪除,恢復時把所有該表空間上表的數據回退到故障點之前的某個時間點,而有時往往并不想這么做。因此,對于粒度更細的精確到表級別的恢復,TSPITR并非最佳方式,利用閃回特性來恢復才是更好的方案。
聲明:本網頁內容旨在傳播知識,若有侵權等問題請及時與本網聯系,我們將在第一時間刪除處理。TEL:177 7030 7066 E-MAIL:11247931@qq.com