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
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.
可以通过执行计划看性能，这两者之间没有差异，一样的执行计划
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