要在RMAN中启用控制文件文件自动备份功能,下面命令是正确的()
A. CONFIGURE CONTROLFILE AUTOBACKUP
B. CONFIGURE CONTROLFILE AUTOBACKUP ON
CONFIGURE CONTROLFILE AUTOBACKUP START
D. CONFIGURE CONTROLFILE AUTOBACKUP STARTUP
在Oracle中,有一个教师表teacher的结构如下:IDNUMBER(5),NAMEVARCHAR2(25),EMAILVARCHAR2(50)下面语句显示没有Email地址的教师姓名()
A. select name from teacher where email=null;
B. select name from teacher where email<>null;
C. select name from teacher where email is null;
D. select name from teacher where email is not null;
下列操作可以用来为一个备份操作手动分配通道的是()
ALLOCATE CHANNEL
B. CREATE CHANNEL
CHANNEL ALLOCATE
D. CREATE LINK
在Oracle数据库系统中,控制文件突然坏了,数据库是打开状态,恢复控制文件()
A. create pfile from spfile
B. alter database backup controlfile to trace
C. alter system set control file=/orctl
D. 没有办法恢复控制文件