（229）Which statements are true regarding SecureFile LOBs?(Choose all that apply.)

A. The amount of undo retained is user controlled.

B. SecureFile LOBs can be used only for nonpartitioned tables.

C. Fragmentation is minimized by using variable-sized chunks dynamically.

D. SecureFile encryption allows for random reads and writes of the encrypted data.

E. It automatically detects duplicate LOB data and conserves space by storing only one copy.

答案：（C、D）