1
GATE CSE 2019
+2
-0.67
Let the set of functional dependencies

F = {QR → S, R → P, S → Q}

hold on a relation schema X = (PQRS). X is not in BCNF. Suppose X is decomposed into two schemas Y and Z, where Y = (PR) and Z = (QRS).

Consider the two statements given below.

I. Both Y and Z are in BCNF
II. Decomposition of X into Y and Z is dependency preserving and lossless

Which of the above statements is/are correct?
A
I only
B
Neither I nor II
C
II only
D
Both I and II
2
GATE CSE 2015 Set 1
Numerical
+2
-0

Consider an Entity-Relationship (ER) model in which entity sets E1 and E2 are connected by an m : n relationship R12. E1 and E3 are connected by a 1 : n (1 on the side of E1 and n on the side of E3) relationship R13.

E1 has two single-valued attributes a11 and a12 of which a11 is the key attribute. E2 has two single-valued attributes a21 and a22 of which a21 is the key attribute. E3 has two single-valued attributes a31 and a32 of which a31 is the key attribute. The relationships do not have any attributes.

If a relational model is derived from the above ER model, then the minimum number of relations that would be generated if all the relations are in 3NF is _______.

3
GATE CSE 2014 Set 1
+2
-0.6
Given the following two statements:
$$S1:$$ Every table with two single-valued attributes is in $$1NF, 2NF, 3NF$$ and $$BCNF.$$
$$S2:$$ $$AB \to C,\,\,D \to E,\,\,E \to C$$ is a minimal cover for the set of functional dependencies $$AB \to C,$$ $$D \to E,\,\,AB \to E,\,\,E \to C.$$

Which one of the following is CORRECT?

A
$$S1$$ is TRUE and $$S2$$ is FALSE
B
Both $$S1$$ and $$S2$$ are TRUE.
C
$$S1$$ is FALSE and $$S2$$ is TRUE.
D
Both $$S1$$ and $$S2$$ are FALSE.
4
GATE CSE 2013
+2
-0.6
Relation $$R$$ has eight attribution $$ABCDEFGH.$$ Fields of $$R$$ contain only atomic values.
$$F = \left\{ {CH \to G,\,\,A \to BC,\,B \to CFH,\,\,E \to A,\,\,F \to EG} \right\}$$ set of functional dependencies $$(FDs)$$ so that $${F^ + }$$ is exactly the set of $$FDs$$ that hold for $$R.$$

How many candidate keys does the relation $$R$$ have?

A
$$3$$
B
$$4$$
C
$$5$$
D
$$6$$
GATE CSE Subjects
EXAM MAP
Medical
NEET