1Z0-864 practice - PrepKeys

Q2 Multiple choice

You are designing a new subsystem to store and search user comments on a fashion company's web site.
There are a large number of comments and they are indexed in several ways to provide fast access. The class used to add and search for comments is called CommentManager. In the prototype, the comments are stored in the file system, but they will be moved to a database as soon as it is available.

Which two statements facilitate modifying the system to use a database? (Choose two.)

Select all that apply.

A
The storage mechanism must be private to CommentManager.
B
CommentManager should provide a JDBC driver for a file system-based database.
C
The comments stored in CommentManager should only be accessed by CommentManager.
D
CommentManager should be a singleton object and all the accessor methods must be static.