The questions can come in any order, so make sure you are selecting right option for all questions.
1. Which of the following is NOT a goal of Dependency Preservation?
(d) Introducing anomalies in the database
2. Why is it important to preserve functional dependencies during decomposition?
(b) To avoid data inconsistencies and anomalies.
3. What disadvantage is associated with lossless join and dependency preserving decomposition?
(a) Increased complexity
4. What is Lossless Decomposition in the context of Database Management Systems (DBMS)?
(b) Decomposing a relation in a way that the natural join of resulting relations yields the original relation.
5. How is Lossless Decomposition achieved in DBMS?
(b) By ensuring that the intersection of resulting relations contains unique data
6. In a lossless join decomposition, what does the condition "Att(R1) ∩ Att(R2) ≠ Φ" ensure?
(c) Intersection of attributes of R1 and R2 must not be empty.
7. Dependency Preservation ensures that no functional dependencies are lost during the decomposition process.
(a) TRUE
8. What is the condition for a decomposition to be considered lossy?
(d) R1 ⋈ R2 ⊃ R
9. What is the primary advantage of lossless join and dependency preserving decomposition?
(d) Improved data integrity
10. What is the condition for a decomposition to be considered lossless join?
(b) R1 ⋈ R2 = R
11. Consider a schema R(A,B,C,D) and functional dependencies A->B and C->D which is decomposed into R1(AB) and R2(CD).
This decomposition is dependency preserving decompostion. State True or False
(a) TRUE
12. What is the primary goal of Lossless Decomposition in DBMS?
(b) Preserving original data while eliminating redundancy
13. What is Dependency Preservation in Database Management Systems?
(b) A technique to decompose a relation into smaller relations while preserving functional dependencies.
14. Which condition is NOT required for lossless join decomposition?
(c) Common attribute must be a key for both relations R1 and R2.
15. Consider a relation X = (P, Q, R) decomposed into X1 = (P, Q) and X2 = (Q, W). What is the common attribute between X1 and X2?
(b) Q