UGC NET · PAPER 2
UGC NET Paper 2 Computer Science – Unit 4: Database Management Systems PYQ (June 2025)
Q17. Consider the following three relations: Employee(eid, eName), Comp(cid, cName), Own(eid, cid). Which of the following relational algebra expressions returns the set of eids who own all brands?
- πeid(πeid, cid(Own) ÷ πcid(Comp))
- πeid(πeid(Own) × πcid(Comp))
- πeid(πeid, cid(Own) × πcid(Comp))
- πeid(πeid(Own) × (πcid, cName(Own) ÷ πcid(Comp)))
Q33. Consider R(A, B, C, D, E) be a relation with the following dependencies: C → F, E → A, EC → D, A → B. Which of the following is a key for R?
- CD
- EC
- AE
- AC
Q42. Consider the following statements:
A. Data transformation is involved in the Data mining process.
B. Online database is used in Data warehouse.
C. Classification is a measure of accuracy.
D. K-means clustering algorithm is based on the concept of minimizing the within-cluster variance.
E. Pattern evaluation is a process to identify knowledge based on interestingness measure.
Choose the correct answer from the options given below:
A. Data transformation is involved in the Data mining process.
B. Online database is used in Data warehouse.
C. Classification is a measure of accuracy.
D. K-means clustering algorithm is based on the concept of minimizing the within-cluster variance.
E. Pattern evaluation is a process to identify knowledge based on interestingness measure.
Choose the correct answer from the options given below:
- B, C, E Only
- A, D, E Only
- A, C, E Only
- A, C, D Only
Q52. Consider the relation T1(A, B, C, D, E) with the dependencies {EB → C, D → E, EA → B} and T2(A, B, C, D) with the dependencies {C → A, A → B, A → D}. Which of the following is TRUE?
- T1 is in 3NF
- T2 is in 3NF
- T1 is not in 3NF
- T1 is in 2NF
Q70. In a relational database, which one of the following is CORRECT?
- A relation with only two attributes is always in BCNF.
- If all attributes of a relation are prime attributes then the relation is in BCNF.
- Every relation has at least one non-prime attribute.
- BCNF decomposition preserves functional dependencies.
Q77. Consider the following statements:
A. A non-serial schedule is said to be conflict serializable if it is conflict-equivalent to some serial schedule.
B. A non-serial schedule is said to be view serializable if it is view-equivalent to some serial schedule.
C. A schedule is said to be serial if instructions of participating transactions are chronologically interleaved with each other.
D. A conflict-serializable schedule will be view-serializable also but vice-versa may not be true.
Choose the correct answer from the options given below:
A. A non-serial schedule is said to be conflict serializable if it is conflict-equivalent to some serial schedule.
B. A non-serial schedule is said to be view serializable if it is view-equivalent to some serial schedule.
C. A schedule is said to be serial if instructions of participating transactions are chronologically interleaved with each other.
D. A conflict-serializable schedule will be view-serializable also but vice-versa may not be true.
Choose the correct answer from the options given below:
- A, B, C, D
- A, B, C Only
- A, B, D Only
- B, C, D Only