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: