rman备份db_%d_t%t_s%s_p%p_%T，各个字符含义

backup incremental level 0 database format='l0_%d_%t_%U_%s＿%p'

backup database format '/nfs/bp0/db_%d_t%t_s%s_p%p_%T' plus archivelog;

BACKUP INCREMENTAL LEVEL 0 DATABASE;

format=string 文件路径和名称的格式串，其中可包含宏变量：

%c copy ID

%p backup piece ID

%s backup set ID

%e log sequence

%h log thread ID

%d database name

%n database name(x填充到8个字符)

%I DBID

%f file ID

%F DBID, day, month, year, and sequencer的复合

%N tablespace name

%t timestamp

%M mh mm格式

%Y year yyyy格式

%u backup set+time((x填充到8个字符)

%U %u_%p_%c

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