参数：
LOG_ARCHIVE_DEST：只能归到本地
LOG_ARCHIVE_DEST_1：可归到远程或本地
设置控制文件自动备份
configure controlfileautobackup on
或controlfileautobackup format for device type disk to ‘/orabak/ysdb_ctl_%’;
设置备份集的冗余
将冗余策略保留两份
Configure retention policy to redundancy 2
将冗余策略保留7天
Configure retention policy to recovery window of 7 days
删除过期的备份
将7天前的备份标记为obsolete
Report obsolete;
Delete noprompt obsolete //删除废弃的备份，物理删除
Crosscheck archivelog all //检查是否有过期的归档日志备份
Delete noprompt expired archivelog all //删除过期归档日志备份，不提示
Crosscheck backup; //校验是否有过期的备份集
Delete nopromt expired backup //删除过期备份，不提示
配置并行度
Configure device type disk parallelism 4 backup type to backupset;
配置备份优化功能
Configure backup optimization on
配置备份片的最大值
Configure channel device type disk maxpiecesize 10g
配置RMAN的备份压缩比例
Configure compression algorithm ‘HIGH’ //高度压缩
MEDIUM/BASIC //中度压缩 LOW //最小的压缩比
配置归档日志的删除策略
Configurearchivelog deletion policy to applied on all standby
