17.08.16

数据文件

 

 

Restore(恢复数据文件)

Recover（写日志）

1.      redo(roll forward)

2.      undo(roll back)

RPO/RTO

数据文件：

不归档方式下丢失一个数据文件：

SQL> archive log list

备份前工作：

SQL> create table t1(x varchar2(50)) tablespace users;

SQL> insert into t1 values ('friday, before backup');

SQL> commit;

备份：  

SQL> 查询v$datafile, v$logfile, v$tempfile, v$controlfile

SQL> shutdown immediate

$ cd $ORACLE_BASE/oradata/

$ cp -r orcl orcl.bak

$ cd $ORACLE_BASE/fast_recovery_area/orcl

$ cp control02.ctl control02.ctl.bak

SQL> startup

备份后工作：

SQL> insert into t1 values ('monday, after backup');

SQL> commit;

故障：

SQL> alter system flush buffer_cache;

$ cd $ORACLE_BASE/oradata/orcl

$ >users01.dbf

SQL> select * from t1;                      报错

$ vi /u01/app/oracle/diag/rdbms/orcl/orcl/trace/alert_orcl.log

$ dbv file=/u01/app/oracle/oradata/orcl/users01.dbf

恢复：

SQL> shutdown abort

$ cd $ORACLE_BASE/oradata

$ rm -rf orcl

$ mv orcl.bak orcl

$ cd $ORACLE_BASE/fast_recovery_area/orcl

$ mv control02.ctl.bak control02.ctl

SQL> startup

SQL> select * from t1;

归档模式下丢失一个数据文件：

SQL> archive log list

备份前工作：

SQL> create table t1(x varchar2(50)) tablespace users;

SQL> insert into t1 values ('friday, before backup');

SQL> commit;

备份：

RMAN> backup tablespace users tag "tbs_users_weekend_backup";

备份后工作：

SQL> select group#, sequence#, status, archived from v$log;

SQL> insert into t1 values ('after backup, logseq 7, archived');

SQL> commit;

SQL> alter system switch logfile;

SQL> insert into t1 values ('after backup, logseq 8, archived');

SQL> commit;

SQL> alter system switch logfile;

SQL> insert into t1 values ('after backup, logseq 9, archived');

SQL> commit;

SQL> alter system switch logfile;

SQL> insert into t1 values ('after backup, logseq 10, current');

SQL> commit;

SQL> insert into t1 values ('after backup, logseq 10, current, uncommitted');

SQL> select * from t1;

故障：

SQL> shutdown abort

$ rm $ORACLE_BASE/oradata/orcl/users01.dbf

SQL> startup                     报错

SQL> select open_mode from v$database;

$ vi /u01/app/oracle/diag/rdbms/orcl/orcl/trace/alert_orcl.log

恢复：

RMAN> list backup of tablespace users;

RMAN> list archivelog all;

SQL> alter database datafile 4 offline;             system和undo tbs不能offline

SQL> alter database open;

RMAN> restore datafile 4;

RMAN> recover datafile 4;

SQL> alter database datafile 4 online;

SQL> select * from t1;

通过不完全恢复解决用户的误操作：

SQL> archive log list

备份前工作：

SQL> create table t1(x varchar2(50)) tablespace users;

SQL> insert into t1 values ('before backup');

SQL> commit;

备份：

RMAN> backup database tag 'weekend_DB_full_backup';

备份后：

SQL> insert into t1 values ('after backup, before delete');

SQL> commit;

误操作：

SQL> select sysdate from dual;

SQL> select dbms_flashback.get_system_change_number from dual;

SQL> delete t1;

SQL> commit;

SQL> create table after_delete (x int);            正确的操作

SQL> insert into after_delete values (1);

SQL> commit;

恢复：

(shutdown abort

Shutup mount)

Startup force mount;

Restore database;

Recover database until scn(or logseq) 1234;

Alter database open;

Or

(shutdown abort

Shutup mount)

RUN{

Startup force mount;

Set until scn 1234;

Restore database;

Recover database;

Alter database open;

}

RMAN> run {

startup force mount;

set until scn= 1806683;

restore database;

recover database;

alter database open resetlogs;

}

set until time=’2015-10-26 11:13:23’;    基于时间点恢复

SQL> select * from t1;

SQL> select * from after_delete;            丢失

SQL> select group#, sequence#, status, archived from v$log;

通过不完全恢复解决归档日志不连续：

SQL> archive log list

备份前：

SQL> create table t1(x varchar2(50)) tablespace users;

SQL> insert into t1 values ('before backup');

SQL> commit;

备份：

RMAN> backup database tag 'weekend_DB_full_backup';

备份后：

SQL> select GROUP#, SEQUENCE#, STATUS, archived from v$log;

SQL> insert into t1 values ('after backup, logseq 1, archived');

SQL> commit;

SQL> alter system switch logfile;

SQL> insert into t1 values ('after backup, logseq 2, archived');

SQL> commit;

SQL> alter system switch logfile;

SQL> insert into t1 values ('after backup, logseq 3, archived');

SQL> commit;

SQL> alter system switch logfile;

SQL> insert into t1 values ('after backup, logseq 4, archived');

SQL> commit;

SQL> alter system switch logfile;

SQL> insert into t1 values ('after backup, logseq 5, current');

SQL> commit;

SQL> alter system checkpoint;

故障：

SQL> shutdown abort

$ rm /u01/app/oracle/oradata/orcl/users01.dbf

$ rm /u01/app/oracle/fast_recovery_area/ORCL/archivelog/2016_03_01/o1_mf_1_5_cfbcxo84_.arc

恢复：

SQL> startup

先尝试只恢复一个数据文件失败。

RMAN> run {

startup force mount;

set until sequence 5;

restore database;

recover database;

alter database open resetlogs;

}

SQL> select * from t1;