单项选择题
A.flash back the database
B.perform point-in-time recovery
C.perform a full database recovery
D.drop and re-create the tablespace
E.use Recovery Manager （RMAN） to recover the database
多项选择题 our database is in the MOUNT state and you execute the following command to open it： ALTER DATABASE OPEN What two actions are performed as a result of this command？（）
单项选择题 Anyonewhoknowsjustthehostnameandthelistenernamecanhavefullcontroloverthelistener.Theycanstopthelistenerandalsoobtaindetailedinformationaboutthelistener，database，andtheconfigurationoftheapplication.Howwouldyouavoidthisscenario？（）
单项选择题 Youareworkingona24x7（available24hoursperday，7daysperweek）productiondatabase.Anoperatingsystem（OS）userdeletesthealertlogfileaccidentally.Whichstatementinthisscenarioistrue？（）