Evaluate the following two queries: Which statement is true regarding the above two queries?

The correct answer is C. There would be no change in performance. 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.

Using Subqueries to Solve Queries

Question

Evaluate the following two queries:

Which statement is true regarding the above two queries?

Options

APerformance would improve in query 2 only if there are null values in the CUST_CREDIT_LIMIT
BPerformance would degrade in query 2
CThere would be no change in performance
DPerformance would improve in query 2

How the community answered

(22 responses)

A
5% (1)
B
9% (2)
C
73% (16)
D
14% (3)

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.

Topics

#query performance#NULL values#NVL#subquery optimization

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