12C之五备份恢复、闪回CDB与PDB。
（1） 备份整个CDB
rman target /
backup as compressed backupset database plus archivelog delete all input;
（2） 备份pluggable库
backup as compressed backupset pluggable database orclpdb;
（3）恢复PDB的system表空间
sqlplus system/oracle@orclpdb
select file_name from dba_data_files;
! rm /u01/app/oracle/oradata/orcl/orclpdb/system01.dbf
rman target /
shutdown abort
start mount
restore tablespace orclpdb:system;
recover tablespace orclpdb:system;
alter database open;
alter pluggable database orclpdb open;
至此恢复完毕
也可以将整个PDB恢复到方式实现
rman target /
shutdown abort;
startup mount;
restore pluggable database orclpdb;
recover pluggable database orclpdb;
alter database open;
alter pluggable database orclpdb open;
（4） 恢复PDB的非关键文件（高可用恢复）
创建测试表空间
create tablespace users datafile ‘/u01/app/oracle/oradata/orcl/orclpdb/users01.dbf’ size 10m;
create table t (id number)
insert into t values(100);
commit;
alter table t move tablespace users;
!rm /u01/app/oracle/oradata/orcl/orclpdb/users01.dbf
(这里清除Buffer cache验证表t无法查询数据）
sqlplus system/oracle@orclpdb
alter tablespace users offline immediate
(这里文件已经删除了，必须使用immediate,否则报错文件不存在）
rman target /
restore tablespace orclpdb:users;
recover tablespace orclpdb:users;
sqlplus system/oracle@orclpdb
alter tablespace users online;
（5）备份控制文件夹
alter database backup controlfile to trace;
cd /u01/app/oracle/diag/rdbms/orcl/orcl/trace/
ls -ltr | tail -10
配置RMAN自动备份
(6) 恢复控制文件
方法1：直接拷贝完好的副本
方法2：使用trace的脚本
方法3：使用RMAN自动备份恢复。
select name from v$controlfile;
!rm /u01/app/oracle/fast_recovery_area/orcl/control02.ctl
此时尝试关闭数据库，无法关库（关库需要写控制文件，完全检查点），报错
shutdown abort;
rman target /
startup nomount;
restore controlfile from autobackup;
alter database mount;
recover database;
alter database open resetlogs;
sqlplus / as sysdba
alter pluggable database orclpdb open;
后再做一次全备份
rman target /
backup as compressed backupset database plus archivelog delete all input;
（7）恢复重做日志文件
先向日志组添加成员
alter database add logfile member '/u01/app/oracle/oradata/orcl/redo01_2’ to group 1;
alter database add logfile member '/u01/app/oracle/oradata/orcl/redo02_2' to group 2;
alter database add logfile member '/u01/app/oracle/oradata/orcl/redo03_2’ to group 3;
切换日志，让所有新成员都有数据。
查看当前日志状态
SQL> select group#,sequence#,archived,status from v$log;
GROUP# SEQUENCE# ARC STATUS
---------- ---------- --- ----------------
1 10 NO CURRENT
2 8 YES INACTIVE
3 9 YES INACTIVE
我们删除当前Group1 的某个日志成员
!rm -f /u01/app/oracle/oradata/orcl/redo01_2
group1—/u01/app/oracle/oradata/orcl/redo01_2
group1—/u01/app/oracle/oradata/orcl/redo01
如何恢复呢，通过clear的方式尝试重新格式化重做日志
alter database clear logfile group 1;
但是该日志的当前在用的，系统报错
下面尝试切换日志
alter system switch logfile;
切换成功后，查询日志状态
SQL> select group#,sequence#,archived,status from v$log;
GROUP# SEQUENCE# ARC STATUS
---------- ---------- --- ----------------
1 10 YES ACTIVE
2 11 NO CURRENT
3 9 YES INACTIVE
再clear，可能依然报错，需要通过完全检查点推进，使得日志组1实例恢复不再需要。
alter database clear logfile group 1;
ERROR at line 1:
ORA-01624: log 1 needed for crash recovery of instance orcl (thread 1)
ORA-00312: online log 1 thread 1: '/u01/app/oracle/oradata/orcl/redo01.log'
ORA-00312: online log 1 thread 1: '/u01/app/oracle/oradata/orcl/redo01_2
alter system checkpoint;
继续clear
alter database clear logfile group 1;
此时成功！
验证：
!ls -l /u01/app/oracle/oradata/orcl/redo*
其他
如新增日志组
alter database add logfile group 1 '/u01/app/oracle/oradata/orcl/redo01.log' size 200m;
删除日志成员
alter database drop logfile member '/u01/app/oracle/oradata/orcl/redo01.log'
注意：操作系统文件依然存在，需要手工删除
