Which statements are true regarding table compression? (Choose all that apply.)

A. It saves disk space and reduces memory usage.
B. It saves disk space but has no effect on memory usage.
C. It incurs extra CPU overhead during DML as well as direct loading operations.

D. It incurs extra CPU overhead during DML but not direct loading operations.
E. It requires uncompress operation during I/O.
Answer: A,C

关于表压缩哪些说法是正确的？
A. 它可以节省磁盘空间，并降低内存使用率。
C. 它在数据操作语言以及直接装载操作期间产生额外的CPU开销。