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GATE CS Practice: Databases
This includes
- 10 questions · 10 marks
- 20 minutes
- Language: English
About quiz
10 questions on normal forms, keys, SQL, relational algebra and transactions (GATE CS Section 9).
Test details
10Questions
10Marks
20 minDuration
1Sections
10 questions · 1 mark each · no negative marking. Solutions are shown after you submit.
Practice questions
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Q1. R(A, B, C) has functional dependencies A → B and B → C. What is the highest normal form R satisfies? (1 mark)
Q2. R(A, B, C, D) has A as its only candidate key. How many super keys does R have? (1 mark)
Q3. A transaction reads a value written by another transaction that has not committed yet. This is called a: (1 mark)
Q4. R(a, b) has 100 tuples and S(b, c) has 50 tuples. b is the primary key of S and a non-null foreign key in R referencing S. How many tuples are in R ⋈ S? (1 mark)
Q5. In a B+ tree, pointers to the actual data records are stored in: (1 mark)
Q6. Table T has 10 rows and column x is NULL in 3 of them. What does SELECT COUNT(x) FROM T return? (1 mark)
Q7. Schedule: r1(A), w2(A), w1(A). Which statement is true? (1 mark)
Q8. A natural join R ⋈ S can be expressed using which basic operations? (1 mark)
Q9. From A → B and B → C we infer A → C. Which Armstrong axiom is this? (1 mark)
Q10. Basic two-phase locking (2PL) guarantees: (1 mark)
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