National University of Computer and Emerging Sciences, Lahore Campus Course: Program: Date: Quiz Section
Database Systems BS(Computer Science) 27-Mar-2019 3
Course Code: Semester: Total Marks: Weight: Max. Time:
CS203 Spring 2019 10
Q1. Consider the relation schema R (A, B, C, D, E, F), with FDs F = {AB→CD, B→C, BC→D, CD→EF, E→F}. Compute the minimal cover for F (i.e. Fc). Show your work! ANSWER: Fc = {B→CD, CD→E, E→F} OR Fc = {AB→CD, B→C, BC→D, CD→EF, E→F} Key is {AB}. Q2. Consider the relation schema R (A, B, C, D, E, H), with FDs F = {A → BC, B → CE, A → E, AC → H, D → B}. Compute the minimal cover for F (i.e. Fc). Show your work! Ans: Fc = {A → BH, B → CE, D → B} OR Fc = {A → BC, B → CE, A → E, AC → H, D → B} Key is {AD}.
Q3. Consider the relation schema R (A, B, C, D, E, F), with a set of FDs F = {A→ BC, FC→ D , D→ B , AB→ F , F→ C, AD→ E}. Compute the minimal cover for F (i.e. Fc). Show your work! Ans:
Fc = { A→ BC , FC→ D , D→ B , AB→ F , F→ C, AD→ E } or Fc = { A→ EF, F→ CD, D→ B } Key is {A}.