Database Management Systems – Previous Year Questions
218 questions from past UGC NET Paper 2 – Computer Science papers, each with the correct answer. Open any question for its explanation.
- Which of the following relations can NOT be decomposed into BCNF with a lossless join and dependency-preserving decomposition?
- Which of the following best describes the structure of a relational database?
- Arrange the following phases of database design in the correct order: (A) Physical Design (B) Conceptual Design (C) Logical Design (D) Requirement Analysis Choose the correct answer from the options given below:
- "CREATE TABLE T" in SQL is an example of:
- Which of the following statements are CORRECT? (A) Granularity is the size of data items in a database. (B) Two operations in a schedule are said to be in conflict if they belong to the same transaction. (C) Two schedul…
- Which of the following statements is/are NOT CORRECT? (A) The first record in each block of the data file is known as the actor record. (B) A dense index has index entries for every search-key value in the data file. (C…
- Match List I with List IIList I List II (a) BCNF iff (I) every JD is implied by the candidate keys (b) 5NF iff (II) all underlying domains contain scalar values only (c) 1NF iff (III) every MVD is implied by the candida…
- Find the number of tuples obtained by applying the operation X ⟕X.S = Y.S Y (left outer join).
- The result of the operation X ⟖X.S = Y.S Y (right outer join) will be:
- Which join is used to get all the tuples of relations X and Y, with NULL values for the corresponding missing values?
- The number of tuples obtained by applying a right outer join on relations X and Y is:
- The number of tuples obtained by applying the Cartesian product over X and Y is:
- The total cost of retrieving records in sorted order using an unclustered B+ tree is (P = average number of records per data page, N = number of data pages, F = ratio of the size of a data entry to the size of a data re…
- Let R(A, B, C, D) be a relational schema with functional dependencies A → B, B → C, C → D and D → B. The decomposition of R into (A, B), (B, C), (B, D)
- Consider the following statements: A. A database design is in BCNF if each member of the set of relation schemas that constitutes the design is in BCNF. B. A BCNF schema can have a transitive dependency. C. It is always…
- Which of the following scenarios may lead to an irrecoverable error in a database system?
- Let R(A, B, C, D, E, F) be a relational schema with the functional dependencies C → F, E → A, EC → D, A → B. Which of the following is a key for R?
- Which one of the following is NOT a part of the ACID properties of a database transaction?
- Given the basic ER diagram and the relational model, which of the following is INCORRECT?
- Which of the following concurrency-control protocols ensures both conflict serializability and freedom from deadlock? Statement I: Two-phase locking Statement II: Timestamp ordering
- Which of the following is/are true in case of tree locking (the tree protocol)? A. It ensures shorter waiting times. B. It ensures freedom from deadlock. C. A transaction can lock data items earlier. D. It does not ensu…
- Which of the following statements is/are FALSE? A. A user can assign privileges to any user on any relation. B. A user can assign privileges to other users only on its own relations. C. A system error that leads to acce…
- The techniques used to handle the phantom problem are: A. Time stamping B. Index locking C. Predicate locking D. Execution indexing Choose the correct answer from the options given below:
- What will be the order of the typical steps when processing a high-level query? A. Query optimizer B. Runtime database processor C. Scanning, parsing and validating D. Query code generator Choose the correct answer from…
- Which SQL query retrieves the total number of orders placed by a specific customer?
- Based on the passage, which of the following statements is true?
- Which of the following tables is most likely to have a foreign key referencing another table?
- Which SQL query retrieves the total number of distinct customers who have placed orders?
- Which of the following best describes the relationship between the 'orders' table and the 'customers' table?
- A ______ operation combines the rows of two relations and outputs a new relation that has both input relations' rows in it.