Normalization Quiz  Find the keys, candidate keys of a relational table, find the minimal cover of set of functional dependencies, check whether two sets of FDs are equivalent
Normalization – Find keys, find minimal cover, check for equivalent FDs
1. Let F = {A → B, AB →
E, BG → E, CD → I, E →
C}. The closures, A^{+}, (AE)^{+} and (ADE)^{+} will
be ________.


(a) ABCE, ABDE,
ABCDEI

(b) ABCE,
ABCE, ABCDEI

(c) ABDE, ABCE,
ABCDE

(d) ABCE, ABDE,
ABCDI

Solution: Visit for detailed answer here.


2. Let F = {A → B, A →
C, BC → D}. Can A
determine D uniquely?


(a) Yes

(b) No

Solution: Visit for detailed answer here.


3. Let F = {AB → D, B →
C, BC → D}. Can AC
determine D uniquely?


(a) Yes

(b) No

Solution: Visit for detailed answer here.


4. Let F1 = {A → C, AC →
D, E → AD} and F2 = {A → CD, E →
AH}. Are F1 and F2 are equivalent?


(a) Equivalent

(b) Not Equivalent

Solution: Visit for detailed answer here.


5. Find the minimal
cover of the set of functional dependencies given; {A → BC, B →
C, AB → D}


(a) {A → C, B →
C, AB → D}

(b) {A → C, B →
C, B → D}

(c) {A → B, B → C, A → D}

(d) {A → BC, B →
C, A → D}

Solution: Visit for detailed answer here.


6. Find the minimal
cover of the set of functional dependencies given; {A → C, AB →
C, C → DI, CD → I, EC →
AB, EI → C}


(a) {A → C, C →
DI, C → I, E → A, EI →
C}

(b) {A → C, C → D, C → I, EC → A, EI → C}

(c) {B → C, C →
DI, D → I, E → AB, EI →
C}

(d) {A → C, C →
DI, CD → I, I → C}

Solution: Visit for detailed answer here.


7. Consider a
relation R with set of functional dependencies F as follows; {A → B, C →
D, AC → E, D → F}. How many keys does R have and what
are they?


(a) 1, {(AC)}

(b) 2, {(AC),
(AD)}

(c) 3, {(AC), (BC),
(ABD)}

(d) 2, {(AC),
(ABD)}

Solution: Visit for detailed answer here.


8. Consider a
relation R(A, B, C, D, E) with FDs AB → C, CD → E, C →
A, C → D, D → B. What are the keys of R?


(a) AB, AC, D

(b) AC, BD

(c) AC, AD

(d) AB, AD, C

Solution: Visit
for detailed answer here.


9. Consider a
relation R(A, B, C, D, E) with FDs AB → C, C → A, C →
BD, D → E. What are the
keys of R? Decompose R into 3NF relations.


(a) {C}, R1(ABCD),
R2(DE)

(b) {BD, AB},
R1(ABCD), R2(DE)

(c) {AB, C}, R1(ABCD), R2(DE)

(d) {BD}, R1(ABC),
R2(CDE)

Solution: Visit
for detailed answer here.


10. Consider a
relation with schema R(A, B, C, D) with functional dependencies, BC → A, AD
→ B,
CD → B, AC → D. Find all the candidate keys of R.


(a) AC, BC, CD

(b) AC, BC

(c) AC, AD

(d) BC, CD, A

Solution: Visit
for detailed answer here.

********************
Go back to Online Quizzes home page
No comments:
Post a Comment