OCP-1Z0-新051-61题版本-54

QUESTION NO: 54

Which statements are correct regarding indexes? (Choose all that apply.)

A. For each data manipulation language (DML) operation performed, the corresponding indexes are automatically updated.

B. A nondeferrable PRIMARY KEY or UNIQUE KEY constraint in a table automatically creates a unique index.

C. A FOREIGN KEY constraint on a column in a table automatically creates a non unique key

D. When a table is dropped, the corresponding indexes are automatically dropped

Answer: A,B,D

答案解析：

参考：46：http://blog.csdn.net/rlhua/article/details/12780849

Explanation: