Oracle日志组添加冗余文件和日志组

rac中需要指定thread
添加日志组RAC：
alter database add logfile thread 1 group 1('+DATA','+ARCH') size 1024m;
alter database add logfile thread 2 group 2('+DATA','+ARCH') size 1024m;

单实例：
alter database add logfile group 1('/u01/app/oracle/oradata/bz/redo01.log') size 1024m;

添加日志文件，不需要指定size大小：
alter database add logfile member '+DATA' to group 1;
alter database add logfile member '+DATA' to group 2;
alter database add logfile member '+DATA' to group 3;