使用RMAN备份与恢复数据库（2）——参数文件的备份与恢复
Oracle有两类参数文件：
（1）pfile：文本格式的参数文件，文件名通常为init.ora；
（2）spfile：二进制格式的参数文件，不能直接修改，可以使用alter system修改，文件名通常为spfile.ora，支持RMAN备份。
一、使用RMAN备份参数文件
1、备份参数文件
命令如下：
RMAN> backup spfile format '/home/oracle/rmanbak/spfileorcl.old';Starting backup at -04-09 14:52:14allocated channel: ORA_DISK_1channel ORA_DISK_1: SID=9 device type=DISKchannel ORA_DISK_1: starting full datafile backup setchannel ORA_DISK_1: specifying datafile(s) in backup setincluding current SPFILE in backup setchannel ORA_DISK_1: starting piece 1 at -04-09 14:52:14channel ORA_DISK_1: finished piece 1 at -04-09 14:52:15piece handle=/home/oracle/rmanbak/spfileorcl.old tag=TAGT145214 comment=NONEchannel ORA_DISK_1: backup set complete, elapsed time: 00:00:01Finished backup at -04-09 14:52:15
2、查看备份集
RMAN> list backup of spfile;List of Backup Sets===================BS Key Type LV Size Device Type Elapsed Time Completion Time ------- ---- -- ---------- ----------- ------------ -------------------37Full 80.00KDISK 00:00:00-04-09 14:52:14BP Key: 66 Status: AVAILABLE Compressed: NO Tag: TAGT145214Piece Name: /home/oracle/rmanbak/spfileorcl.oldSPFILE Included: Modification time: -04-09 13:56:52SPFILE db_unique_name: ORCL
二、恢复参数文件
1、连接scott用户
创建t1表，并插入记录：
SQL> show user;USER is "SCOTT"SQL> create table t1(id number(4),name varchar2(20));Table created.Elapsed: 00:00:00.33SQL> insert into t1 values(1,'Jack');1 row created.Elapsed: 00:00:00.09SQL> commit;Commit complete.Elapsed: 00:00:00.00SQL> select * from t1;ID NAME---------- --------------------1 JackElapsed: 00:00:00.01
2、删除参数文件
（1）查看参数文件
SQL> show parameter spfile;NAMETYPE VALUE------------------------------------ ----------- ------------------------------spfilestring /usr/local/oracle/product/11.2.0/db_1/dbs/spfileorcl.ora
（2）删除参数文件
SQL> ! rm /usr/local/oracle/product/11.2.0/db_1/dbs/spfileorcl.oraSQL>
3、重启数据库
重新启动数据库提示无法打开参数文件：
SQL> startupORA-01078: failure in processing system parametersLRM-00109: could not open parameter file '/usr/local/oracle/product/11.2.0/db_1/dbs/initorcl.ora'
由于缺少参数文件，无法启动实例，可以在RMAN中启动一个伪实例到nomount，代码如下：
RMAN> startup nomount;startup failed: ORA-01078: failure in processing system parametersLRM-00109: could not open parameter file '/usr/local/oracle/product/11.2.0/db_1/dbs/initorcl.ora'starting Oracle instance without parameter file for retrieval of spfileOracle instance startedTotal System Global Area158662656 bytesFixed Size 2211448 bytesVariable Size 92275080 bytesDatabase Buffers 58720256 bytesRedo Buffers 5455872 bytes
查看实例信息如下：
SQL> connect / as sysdbaConnected.SQL> show parameter name;NAMETYPE VALUE------------------------------------ ----------- ------------------------------db_file_name_convertstringdb_namestringDUMMYdb_unique_namestringDUMMYglobal_namesboolean FALSEinstance_namestringorcllock_name_spacestringlog_file_name_convert stringservice_namesstringDUMMY
4、使用RMAN还原参数文件
RMAN> restore spfile from '/home/oracle/rmanbak/spfileorcl.old';Starting restore at -04-09 15:47:47using target database control file instead of recovery catalogallocated channel: ORA_DISK_1channel ORA_DISK_1: SID=10 device type=DISKchannel ORA_DISK_1: restoring spfile from AUTOBACKUP /home/oracle/rmanbak/spfileorcl.oldchannel ORA_DISK_1: SPFILE restore from AUTOBACKUP completeFinished restore at -04-09 15:47:49
5、关闭RMAN中的实例
RMAN> shutdown immediateOracle instance shut down
6、启动数据库
SQL> connect / as sysdbaConnected to an idle instance.SQL> startupORACLE instance started.Total System Global Area 1068937216 bytesFixed Size 220 bytesVariable Size 482348888 bytesDatabase Buffers 578813952 bytesRedo Buffers 5554176 bytesDatabase mounted.Database opened.
7、查看数据是否丢失
删除参数文件前的最后一个操作是往scott用户的t1表中插入一条记录，查看t1表中的数据如下：
SQL> select * from scott.t1;ID NAME---------- --------------------1 JackElapsed: 00:00:00.05
