15 questions · 22 marks · 40 minutes. Negative marking on MCQ only: −1/3 mark for a wrong 1-mark MCQ, −2/3 for a wrong 2-mark MCQ. No negative marking for MSQ or NAT; MSQ has no partial credit.
Q1 · MCQ · 1 mark(s) — File problems
A hostel clerk can open and read the exam marks file. Which file-processing problem is this?
- (A) Security
- (B) Redundancy
- (C) Data isolation
- (D) Atomicity
Q2 · MCQ · 1 mark(s) — File problems
A new report needs data from three files in three formats, so a new program must be written. Which two problems are shown?
- (A) Redundancy and security
- (B) Atomicity and concurrency
- (C) Difficult access and data isolation
- (D) Integrity and inconsistency
Q3 · MCQ · 1 mark(s) — DBMS
Which statement about the catalog is correct?
- (A) It stores metadata, making the database self-describing.
- (B) It is used only by naive users.
- (C) It is part of each application program.
- (D) It stores the data values.
Q4 · MSQ · 2 mark(s) — Users
Which are DBA responsibilities?
- (A) Planning backup and recovery
- (B) Running ready-made booking screens all day
- (C) Granting access rights
- (D) Monitoring performance
Q5 · MCQ · 1 mark(s) — Schema
The schema of a database is also called its:
- (A) extension
- (B) intension
- (C) state
- (D) instance
Q6 · MCQ · 2 mark(s) — Independence
The college splits the conceptual record type STUDENT into STUDENT and STUDENT_CONTACT. The library view is redefined on top of the new conceptual schema and the library app runs unchanged. This shows:
- (A) no independence, since a schema changed
- (B) internal schema independence
- (C) physical data independence
- (D) logical data independence
Q7 · MCQ · 1 mark(s) — Data models
Which design step converts an ER diagram into tables?
- (A) Requirements collection
- (B) Physical design
- (C) Conceptual design
- (D) Logical design
Q8 · NAT · 1 mark(s) — Sets
A = {1,2,3,4,5,6}, B = {4,5,6,7}. What is |A − B|?
Numerical answer: ________
Q9 · NAT · 1 mark(s) — Power set
How many subsets of {A, B, C, D, E, F} contain A?
Numerical answer: ________
Q10 · NAT · 2 mark(s) — Cartesian product
dept ∈ {CS, EE, ME, CE}, year ∈ {1, 2, 3, 4}, section ∈ {A, B}. How many (dept, year, section) tuples are possible?
Numerical answer: ________
Q11 · MCQ · 2 mark(s) — Relations
Which property follows from a relation being a set of tuples?
- (A) Every possible tuple is present
- (B) No two tuples are identical
- (C) Tuples must be sorted
- (D) Columns have no names
Q12 · MCQ · 1 mark(s) — Logic
¬(p ∧ ¬q) is equivalent to:
- (A) ¬p ∨ q
- (B) p ∨ ¬q
- (C) ¬p ∧ q
- (D) p ∧ q
Q13 · MCQ · 2 mark(s) — Quantifiers
"Asha has taken every course taught by Rao" is correctly written as:
- (A) ∃c (Rao(c) ∧ Took(Asha, c))
- (B) ∀c (Rao(c) → Took(Asha, c))
- (C) ∀c (Rao(c) ∧ Took(Asha, c))
- (D) ∃c (Rao(c) → Took(Asha, c))
Q14 · NAT · 2 mark(s) — Counting
R(A, B, C, D, E). How many attribute groups contain AB or AC?
Numerical answer: ________
Q15 · NAT · 2 mark(s) — Interleavings
T1 has 2 operations and T2 has 4 operations. How many interleavings keep each transaction's own order?
Numerical answer: ________
✓Answer Vault
Reveal answers when you’re ready
Q1 Answer: (A) · 1 mark(s)
Users see data they should not.
- (B) is wrong: No copies involved.
- (C) is wrong: Isolation is scattered formats.
- (D) is wrong: Not about half-finished tasks.
Re-read: Lesson 0.1.1 — Data vs information; plain files and their problems
Q2 Answer: (C) · 1 mark(s)
New questions need new programs (difficult access) and the data sits in different formats (isolation).
- (A) is wrong: Not shown.
- (B) is wrong: Not shown.
- (D) is wrong: Not shown.
Re-read: Lesson 0.1.1 — Data vs information; plain files and their problems
Q3 Answer: (A) · 1 mark(s)
Catalog = metadata.
- (B) is wrong: It is used by the DBMS and the DBA.
- (C) is wrong: It is inside the DBMS.
- (D) is wrong: Values are in the database itself.
Re-read: Lesson 0.1.2 — What a DBMS is and what it does; its users (end users, application programmers, DBA)
Q4 Answer: (A) (C) (D) · 2 mark(s)
C describes a naive end user.
- (B) is wrong: Not a DBA task.
Re-read: Lesson 0.1.2 — What a DBMS is and what it does; its users (end users, application programmers, DBA)
Q5 Answer: (B) · 1 mark(s)
Schema = intension; instance = extension = state.
- (A) is wrong: That is the instance.
- (C) is wrong: That is the instance.
- (D) is wrong: That is the data now.
Re-read: Lesson 0.1.3 — Schema vs instance; three-schema architecture; logical and physical data independence
Q6 Answer: (D) · 2 mark(s)
A conceptual change hidden from views by changing the external–conceptual mapping.
- (A) is wrong: Independence exactly means apps survive schema changes.
- (B) is wrong: Not a standard term here.
- (C) is wrong: Physical is about internal changes.
Re-read: Lesson 0.1.3 — Schema vs instance; three-schema architecture; logical and physical data independence
Q7 Answer: (D) · 1 mark(s)
Logical design maps the conceptual model to the representational (relational) model.
- (A) is wrong: Before ER.
- (B) is wrong: Chooses storage.
- (C) is wrong: Produces the ER diagram.
Re-read: Lesson 0.1.4 — Data models: conceptual vs logical vs physical; where ER and relational fit
Q8 Answer: 3 · 1 mark(s)
A − B = {1,2,3}: 3.
Re-read: Lesson 0.2.1 — Sets: membership, subset, union, intersection, difference, cardinality, power set
Q9 Answer: 32 · 1 mark(s)
2⁵ = 32.
Re-read: Lesson 0.2.1 — Sets: membership, subset, union, intersection, difference, cardinality, power set
Q10 Answer: 32 · 2 mark(s)
4 × 4 × 2 = 32.
Re-read: Lesson 0.2.2 — Ordered tuples, Cartesian product and its size; a relation as a set of tuples
Q11 Answer: (B) · 2 mark(s)
Sets have no duplicates.
- (A) is wrong: A relation is any subset.
- (C) is wrong: Sets have no order.
- (D) is wrong: Columns are named by the schema.
Re-read: Lesson 0.2.2 — Ordered tuples, Cartesian product and its size; a relation as a set of tuples
Q12 Answer: (A) · 1 mark(s)
De Morgan: ¬p ∨ ¬¬q = ¬p ∨ q (which is also p → q).
- (B) is wrong: Wrong signs.
- (C) is wrong: Wrong connective.
- (D) is wrong: Not equivalent.
Re-read: Lesson 0.2.3 — Logic: propositions, AND/OR/NOT, implication, truth tables, quantifiers and their negation
Q13 Answer: (B) · 2 mark(s)
∀ pairs with →.
- (A) is wrong: Says "some" course.
- (C) is wrong: Says every course in the domain is Rao's.
- (D) is wrong: Trivially true when any non-Rao course exists.
Re-read: Lesson 0.2.3 — Logic: propositions, AND/OR/NOT, implication, truth tables, quantifiers and their negation
Q14 Answer: 12 · 2 mark(s)
Contain AB: 2³ = 8; contain AC: 8; contain ABC: 2² = 4. 8 + 8 − 4 = 12.
Re-read: Lesson 0.2.4 — Counting toolkit: combinations, inclusion–exclusion
Q15 Answer: 15 · 2 mark(s)
C(6, 2) = 15.
Re-read: Lesson 0.2.4 — Counting toolkit: combinations, inclusion–exclusion