QUESTION NO: 59
Evaluate the following two queries:
Which statement is true regarding the above two queries?
A. Performance would improve in query 2 only if there are null values in the CUST_CREDIT_LIMIT column
B. Performance would degrade in query 2
C. There would be no change in performance
D. Performance would improve in query 2
Answer: C
答案解析：
参考：55：http://blog.csdn.net/rlhua/article/details/11837463
Explanation:
Note: The IN operator is internally evaluated by the Oracle server as a set of OR conditions, such
as a=value1 or a=value2 or a=value3. Therefore, using the IN operator has no performance
benefits and is used only for logical simplicity.