oracle數據庫熱備中的備份和恢復及例子
手工熱備（開庫狀態）
備份控制文件：
alter database backup controlfile to ‘/u01/oradata/prod/con.bak1‘;
備份數據文件（這裏用到pl/sql進行批處理,將查詢結果粘貼運行即可）
begin
for i in (select tablespace_name from dba_tablespaces) loop
dbms_output.put_line(‘alter tablespace ‘||i.tablespace_name||‘ begin backup;‘);
for j in (select file_name from dba_data_files where tablespace_name=i.tablespace_name) loop
end loop;
dbms_output.put_line(‘alter tablespace ‘||i.tablespace_name||‘ end backup;‘);
end loop;
end;
模擬現場，舉例
1.刪除emp1表 drop table emp1 purge;(不完全恢復)
模擬：
drop table emp1 purge;
select * from v$log;
alter system switch logfile;
/
解決：
select name from v$archived_log;(可以看到刪除的日誌條目切換到此歸檔日誌裏了)
/u01/flash_recovery_area/PROD/archivelog/2017_08_13/o1_mf_1_6_drzyyodl_.arc
/u01/flash_recovery_area/PROD/archivelog/2017_08_27/o1_mf_1_7_dt4yy16z_.arc
/u01/flash_recovery_area/PROD/archivelog/2017_08_27/o1_mf_1_8_dt4zlzff_.arc
/u01/flash_recovery_area/PROD/archivelog/2017_08_27/o1_mf_1_9_dt4zow6g_.arc
/u01/flash_recovery_area/PROD/archivelog/2017_11_12/o1_mf_1_2_f0jh6xf2_.arc
/u01/flash_recovery_area/PROD/archivelog/2017_11_12/o1_mf_1_3_f0jk4n4p_.arc
/u01/flash_recovery_area/PROD/archivelog/2017_11_13/o1_mf_1_1_f0lkgyt6_.arc
/u01/flash_recovery_area/PROD/archivelog/2017_11_13/o1_mf_1_2_f0lo0fom_.arc
因為今天13號所以選這兩條日誌，也可以多切換幾次日誌多生成幾個日誌條目
接下來進行時間的挖掘（基於時間點來恢復）
mkdir -p /home/oracle/logmnr
show parameter utl_file_dir
alter system set utl_file_dir=‘/home/oracle/logmnr‘ scope=spfile;
startup force;
show parameter utl_file_dir;
alter database add supplemental log data;
execute dbms_logmnr_d.build(‘dict.ora‘,‘/home/oracle/logmnr‘,dbms_logmnr_d.store_in_flat_file);
execute dbms_logmnr.add_logfile(logfilename=>‘/u01/flash_recovery_area/PROD/archivelog/2017_11_13/o1_mf_1_1_f0lkgyt6_.arc‘,options=>dbms_logmnr.new);
execute dbms_logmnr.add_logfile(logfilename=>‘/u01/flash_recovery_area/PROD/archivelog/2017_11_13/o1_mf_1_2_f0lo0fom_.arc‘,options=>dbms_logmnr.addfile);
execute dbms_logmnr.start_logmnr(dictfilename=>‘/home/oracle/logmnr/dict.ora‘,options=>dbms_logmnr.ddl_dict_tracking);
select username,scn,to_char(timestamp,‘yyyy-mm-dd hh24:mi:ss‘) time,sql_redo from v$logmnr_contents WHERE lower(sql_redo) like ‘drop table%‘;
execute dbms_logmnr.end_logmnr;
USERNAME SCN TIME
------------------------------ ---------- -------------------
SQL_REDO
------------------------------------------------------------
UNKNOWN 954522 2017-11-13 16:03:53
drop table emp1 purge;
（記錄此時間2017-11-13 16:03:53）
shutdown abort;
時間挖掘完成。
cd /home/oradata/prod
rm *.dbf
cp /home/oracle/hot_backup/*.dbf ./
startup;
recover database until time ‘2017-11-13 16:03:53‘;auto
alter database open resetlogs;
驗證查看
select * from emp1;
成功找回此表，同樣可以通過scn號尋找恢復，但是不能用閃回表因為我是purge徹底刪除，只能不完全恢復。
2.模擬user01.dbf 介質損壞
rm -rf /u01/oradata/prod/users01.dbf
例如shutdown immediate
SYS@prod>shutdown immediate
ORA-01116: 打開數據庫文件 4 時出錯
ORA-01110: 數據文件 4: ‘/u01/oradata/prod/users01.dbf‘
ORA-27041: 無法打開文件
解決：
alter system flush buffer_cache;
alter tablespace users offline immediate;
cp /home/oracle/hot_backup/users01.dbf /u01/oradata/prod/
recover tablespace users;auto
alter tablespace users online;
3.模擬undotbs1 介質損壞(恢復的方法多種我只演示根據文件號恢復)
select name from v$datafile;
rm -rf /u01/oradata/prod/undotbs01.dbf
shutdown abort
解決：
SYS@prod>select FILE#,ERROR from v$recover_file;
FILE# ERROR
---------- -----------------------------------------------------------------
1 UNKNOWN ERROR
2 UNKNOWN ERROR
3 FILE NOT FOUND
SYS@prod>select FILE#,NAME from v$datafile;
FILE# NAME
--------------------------------------------------
1 /u01/oradata/prod/system01.dbf
2 /u01/oradata/prod/sysaux01.dbf
3 /u01/oradata/prod/undotbs01.dbf
4 /u01/oradata/prod/users01.dbf
5 /u01/oradata/prod/example01.dbf
SYS@prod>select file#,checkpoint_change# from v$datafile_header;
FILE# CHECKPOINT_CHANGE#
---------- ------------------
1 975649
2 975649
3 0
4 975649
5 975649
確定3號文件損壞
cp /home/oracle/hot_backup/undotbs01.dbf /u01/oradata/prod/
recovere datafile 3;auto
alter database open;
4.當前日誌，介質損壞
create table t2(id int);
insert into t2 values(100);
commit;
alter system archive log current;
insert into t2 values(200);
commit;
select * from scott.t2;
select group#,sequence#,status from v$log;
select GROUP#,MEMBER from v$logfile;
查出當前的日誌是組號是1對應的redo01.log
模擬 rm -rf /u01/oradata/prod/redo01.log
shutdown abort
startup
數據庫裝載完畢。
ORA-00313: 無法打開日誌組 1 (用於線程 1) 的成員 ORA-00312:
聯機日誌 1 線程 1: ‘/u01/oradata/prod/redo01.log‘
ORA-27037: 無法獲得文件狀態 Linux
Error: 2: No such file or directory
Additional information: 3
解決:
cd /u01/oradata/prod/
rm *.dbf
cp /home/oracle/hot_backup/*.dbf ./
startup
recover database until cancel;auto
recover database until cancel;cancel
alter database open resetlogs;
select * from scott.t1;
ID
----------
100
5.控制文件損壞
rm -rf /u01/oradata/prod/control01.ctl
rm -rf /u01/flash_recovery_area/prod/control02.ctl
shutdown abort
startup
ORA-00205: ?????????, ??????, ???????
select status from v$instance;
解決：
cp /home/oracle/control01.ctl /u01/oradata/prod/
cp /home/oracle/control02.ctl /u01/flash_recovery_area/prod/
recover database using backup controlfile;auto
recover database using backup controlfile;當前的日誌
alter database open resetlogs;
oracle數據庫熱備中的備份和恢復及例子