多项选择题 What is true regarding the role Oracle Net provides in a client server connection with no middle tier？（）

单项选择题 You discover that a disk failure occurred on DISK3 where the data file belonging to the USER_DATA table space is stored. The database is currently open and you need to recover the data file. You will restore the data file to DISK2.  What is the correct sequence RMAN commands to restore and recover the data file？（）

多项选择题 WhichtwostatementsregardingthecontrolfileandRecoverManageraretrue？（）