多选题

知识点：数据库 7/10（多选/必答） Which of the foll...

Question

知识点：数据库 7/10（多选/必答）
Which of the following statement is true about the normalization?

A. After 2NF, we can still have redundant data.

B. A relation is said to be in first normal form if and only if all underlying domains contain atomic values only. After 1NF, we can still have redundant data.

C. A relation is said to be in 3NF, if and only if it is in 2NF and every non key attribute is non-transitively dependent on the primary key.

D. The process of removing the redundant data, by splitting up the table in a well defined fashion is called normalization.