Armstrong (1974) proposed systematic approach to derive functional…
2013
Armstrong (1974) proposed systematic approach to derive functional dependencies. Match the following w.r.t. Functional dependencies:
List – I
a. Decomposition rule
b. Union rule
c. Composition rule
d. Pseudo transitivity rule
List – II
i. If X → Y and Z → W then {X, Z} → {Y, W}
ii. If X → Y and {Y, W} → Z then {X, W} → Z
iii. If X → Y and X → Z then X → {Y, Z}
iv. If X → {Y, Z} then X → Y and X → Z
- A.
iii ii iv i
- B.
i iii iv ii
- C.
ii i iii iv
- D.
iv iii i ii
Attempted by 322 students.
Show answer & explanation
Correct answer: D
The correct matching is a-iv, b-iii, c-i, d-ii. Decomposition rule states if X → {Y, Z} then X → Y and X → Z (iv). Union rule states if X → Y and X → Z then X → {Y, Z} (iii). Composition rule states if X → Y and Z → W then {X, Z} → {Y, W} (i). Pseudo transitivity rule states if X → Y and {Y, W} → Z then {X, W} → Z (ii).
A video solution is available for this question — log in and enroll to watch it.