单项选择题
What RMAN command must you use before you can back up a database using the recovery catalog？（）
A. create catalog B. install database C. catalog database D. merge Catalog with database E. register database
单项选择题 YoucanbackuptheRMANrecoverycatalogwithRMAN.（）
单项选择题 RMANprovidesmoregranularcatalogsecuritythroughwhichfeature？（）
多项选择题 WhatisthepurposeoftheRMANrecoverycatalog？（）
