問題文
A DBA fills the standby creation form, leaves the identifier prefix row empty, and then asks the naming board how far the uniqueness of the database unique name has to reach before Oracle will accept the form. Where does an empty prefix draw its characters from, and what edge does the unique name have to be unique inside?
選択肢
- An empty prefix borrows the random segment straight away and uniqueness reaches just the cluster boundary.
- An empty prefix borrows the opening segment straight away and uniqueness reaches just the cluster boundary.
- An empty prefix borrows the opening segment straight away and uniqueness reaches just the realm boundary.
- An empty prefix borrows the random segment straight away and uniqueness reaches just the realm boundary.