20170816上课笔记

数据文件恢复通过数据文件和归档日志和联机重做日志（正在使用中的）达到恢复效果

恢复数据库其实是做两个操作

一restore（恢复数据文件）//完全恢复哪个文件有问题恢复哪个，不完全恢复数据库完全恢复

二recover（写日志）

1. redo（roll forward）//前滚照着归档日志完全回放

2. undo(roll back) //撤销回滚没有提交的工作

数据文件

RPO/RTO

数据文件：

不归档方式下丢失一个数据文件：//不归档模式下备份直接用cp

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//复制目录

$ 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//输出重定向

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;//查看当前数据库状态

$ vi /u01/app/oracle/diag/rdbms/orcl/orcl/trace/alert_orcl.log//查看警报日志

恢复：

RMAN> list backup of tablespace users;

RMAN> list archivelog all;

SQL> alter database datafile 4 offline;//暂时离线损坏数据文件 system和undo tbs不能offline

SQL> alter database open;//打开数据库，不离线损坏数据文件无法打开数据库注意若系统表空间出错，无法离线

RMAN> restore datafile 4;

RMAN> recover datafile 4;

SQL> alter database datafile 4 online;//让离线文件上线

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

startup mount）= startup force mount;

restore database

recover database until scn/logseq/timestamp //恢复到指定时间点

alter database open resetlogs

//用run包装执行因为有scn点所以可以指定恢复时间点

logminer //搜索用户误操作命令所在

RMAN> run {

startup force mount;

set until scn= 1806683;

restore database;

recover database;

alter database open resetlogs;//联机重做日志清零

}

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;//写5则恢复到4 写n即恢复到

restore database;

recover database;

alter database open resetlogs;

}

SQL> select * from t1;

控制文件

丢失部分控制文件：

SQL> select * from v$controlfile;

$ >/u01/app/oracle/oradata/orcl/control01.ctl

SQL> select * from v$tablespace; 报错

SQL> alter system checkpoint; 报错

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

SQL> shutdown abort

SQL> startup nomount

SQL> show parameter control_files

$ cp /u01/app/oracle/fast_recovery_area/orcl/control02.ctl /u01/app/oracle/oradata/orcl/control01.ctl

SQL> alter database mount;

SQL> alter database open;

丢失全部控制文件（有自动备份）：

RMAN> CONFIGURE CONTROLFILE AUTOBACKUP ON;

RMAN> backup datafile 4;

$ >/u01/app/oracle/oradata/orcl/control01.ctl

$ >/u01/app/oracle/fast_recovery_area/orcl/control02.ctl

SQL> select * from v$tablespace; 报错

SQL> alter system checkpoint; 报错

SQL> shutdown abort

SQL> startup nomount

RMAN> restore controlfile from autobackup;

RMAN> alter database mount;

RMAN> recover database;

RMAN> alter database open resetlogs;

丢失全部控制文件（没有自动备份）：

SQL> alter database backup controlfile to '/home/oracle/control.bak';

SQL> alter database backup controlfile to trace;

SQL> select * from v$diag_info;

//不管在oracle中遇到任何问题，只要数据库还没关，就不要手动去关闭，尽量在数据库中解决问题

spfile

有自动备份：

RMAN> CONFIGURE CONTROLFILE AUTOBACKUP ON;

RMAN> backup datafile 4;

联机恢复：

$ mv $ORACLE_HOME/dbs/spfileorcl.ora $ORACLE_HOME/dbs/spfileorcl.ora.bak

SQL> alter system set resource_limit=true; 报错

SQL> create spfile='/home/oracle/spfile.bak' from memory;//当数据库还在连接中发现问题时，可用此语句恢复

$ mv /home/oracle/spfile.bak $ORACLE_HOME/dbs/spfileorcl.ora

脱机恢复：

SQL> shutdown immediate

$ mv $ORACLE_HOME/dbs/spfileorcl.ora $ORACLE_HOME/dbs/spfileorcl.ora.bak

RMAN> startup//在rman下执行startup 使之启动实例但不通过配置参数

RMAN> restore spfile from '/u01/app/oracle/fast_recovery_area/ORCL/autobackup/2015_10_26/o1_mf_s_894118741_c2vkgo8x_.bkp';

RMAN> startup force //重启

没有备份：

利用alert_orcl.log中的参数值，构造initorcl.ora //在最后1次启动下找到参数复制保存到initorcl.ora

SQL> create spfile='/home/oracle/spfile.bak' from pfile;

利用备份init.ora：

$ vi /u01/app/oracle/product/11.2.0/db_1/dbs/init.ora 完善参数

SQL> startup pfile='/u01/app/oracle/product/11.2.0/db_1/dbs/init.ora'

SQL> create spfile from pfile;