快速恢复区概念是一个默认放置所有备份恢复操作有关文件的地方,包括:控制文件在线镜像、在线重做日志、归档日志、外来归档日志、控制文件镜像复制、数据文件镜像复制、RMAN备份片和闪回日志。如果启用的快速恢复区,它就成了RMAN备份默认的去处,无论是RMAN备份片、镜像复制、还是控制文件自动备份,只要没有在RMAN配置或则backup命令中指明路径就全部进入快速恢复区。
快速恢复区由两个参数确定:
SQL> show parameter db_recovery NAME TYPE VALUE------------------------------------ ----------- ------------------------------db_recovery_file_dest stringdb_recovery_file_dest_size big integer 0db_recovery_file_dest:用于设置快速恢复区的路径。
db_recovery_file_dest_size:用于设置快速恢复区的大小。
注:设置快速恢复区要先设置大小,后设置路径。
1、 设置快速恢复区路径大小4G,存储路径为/u01/app/Oracle/fast_recovery_area
SQL> alter system set db_recovery_file_dest_size=4G scope=spfile;System altered.
SQL> alter system set db_recovery_file_dest='/u01/app/oracle/fast_recovery_area' scope=spfile;System altered.
SQL> shutdown immediateDatabase closed.Database dismounted.ORACLE instance shut down.SQL> startupORACLE instance started.Total System Global Area 830930944 bytesFixed Size 2257800 bytesVariable Size 536874104 bytesDatabase Buffers 285212672 bytesRedo Buffers 6586368 bytesDatabase mounted.Database opened.SQL> SQL> show parameter db_recovery;NAME TYPE VALUE------------------------------------ ----------- ------------------------------db_recovery_file_dest string /u01/app/oracle/fast_recovery_ areadb_recovery_file_dest_size big integer 4G2、 reset快速恢复区
1)方法一:修改pfile参数文件
SQL> shutdown immediateDatabase closed.Database dismounted.ORACLE instance shut down.SQL> create pfile from spfile;File created.
SQL> !vi $ORACLE_HOME/dbs/initdrz.ora
删除如下内容
*.db_recovery_file_dest_size=4294967296*.db_recovery_file_dest='/u01/app/oracle/fast_recovery_area'
SQL> create spfile from pfile;File created.SQL> startupORACLE instance started.Total System Global Area 830930944 bytesFixed Size 2257800 bytesVariable Size 536874104 bytesDatabase Buffers 285212672 bytesRedo Buffers 6586368 bytesDatabase mounted.Database opened.SQL> SQL> show parameter db_recoveryNAME TYPE VALUE------------------------------------ ----------- ------------------------------db_recovery_file_dest stringdb_recovery_file_dest_size big integer 0
2)方法二:reset命令
SQL> alter system reset db_recovery_file_dest_size scope=spfile sid='*';System altered.SQL> alter system reset db_recovery_file_dest scope=spfile sid='*';System altered.SQL> SQL> shutdown immediateDatabase closed.Database dismounted.ORACLE instance shut down.SQL> startupORACLE instance started.Total System Global Area 830930944 bytesFixed Size 2257800 bytesVariable Size 536874104 bytesDatabase Buffers 285212672 bytesRedo Buffers 6586368 bytesDatabase mounted.Database opened.SQL> SQL> show parameter db_recoveryNAME TYPE VALUE------------------------------------ ----------- ------------------------------db_recovery_file_dest stringdb_recovery_file_dest_size big integer 0
总结:从Oracle原理上来分析,直接修改参数文件不失为一种很好理解的方式,但reset语句修改,更方便。
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