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Practice Questions
Test your understanding with targeted questions related to the topic.
Question 1
Easy
What does the projection operation do in database queries?
π‘ Hint: Think about what the projection symbol (Ο) represents.
Question 2
Easy
Which method is used to handle duplicates during projection?
π‘ Hint: Consider how you might identify similar items.
Practice 4 more questions and get performance evaluation
Interactive Quizzes
Engage in quick quizzes to reinforce what you've learned and check your comprehension.
Question 1
What does the projection operation (Ο) do?
- Selects rows based on conditions
- Extracts specific columns
- Sorts data
π‘ Hint: Think about what 'selecting columns' refers to.
Question 2
True or False: The projection operation automatically eliminates duplicate rows.
- True
- False
π‘ Hint: Consider what happens when you select non-unique entries.
Solve 2 more questions and get performance evaluation
Challenge Problems
Push your limits with challenges.
Question 1
How would you improve the performance of a projection operation that queries a large dataset with many duplicate records?
π‘ Hint: Evaluate the existing structures and indexes in your database.
Question 2
Explain how the choice of evaluation strategy (either Scan and Write or Index-Only Scan) may affect SQL query performance in real-world scenarios.
π‘ Hint: Consider database sizes and complexities when making your choice.
Challenge and get performance evaluation