OCP-1Z0-051-2015-59题

QUESTION NO: 59

Evaluate the following two queries:

Exhibit:

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（degrade降低）
C. There would be no change in performance（没有变化）
D. Performance would improve in query 2（improve提高）
Answer: C
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.