Practice - Projection (pi) Operation (Selecting Columns)
Practice Questions
Test your understanding with targeted questions
What does the projection operation do in database queries?
💡 Hint: Think about what the projection symbol (π) represents.
Which method is used to handle duplicates during projection?
💡 Hint: Consider how you might identify similar items.
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Interactive Quizzes
Quick quizzes to reinforce your learning
What does the projection operation (π) do?
💡 Hint: Think about what 'selecting columns' refers to.
True or False: The projection operation automatically eliminates duplicate rows.
💡 Hint: Consider what happens when you select non-unique entries.
2 more questions available
Challenge Problems
Push your limits with advanced challenges
How would you improve the performance of a projection operation that queries a large dataset with many duplicate records?
💡 Hint: Evaluate the existing structures and indexes in your database.
Explain how the choice of evaluation strategy (either Scan and Write or Index-Only Scan) may affect SQL query performance in real-world scenarios.
💡 Hint: Consider database sizes and complexities when making your choice.
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Reference links
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