1
GATE CSE 2002
+2
-0.6
From the following instance of a relation schema $$R(A, B, C),$$ we can conclude that:
A
A functionally determines $$B$$ and $$B$$ functionally determines $$C$$
B
A functionally determines $$B$$ and $$B$$ does not functionally determines $$C$$
C
$$B$$ does not functionally determines $$C$$
D
A does not functionally determine $$B$$ and $$B$$ does not functionally determine $$C$$
2
GATE CSE 2002
+2
-0.6
Relation $$R$$ is decomposed using a set of functional dependencies, $$F,$$ and relation $$S$$ is decomposed using another set of functional dependencies, $$G.$$ One decomposition is definitely $$BCNF,$$ the other is definitely. $$3NF,$$ but it is not known which is which. To make a guaranteed identification, which one of the following tests should be used on the decompositions? (Assume that the closures of $$F$$ and $$G$$ are available).
A
Dependency-preservation
B
Lossless-join
C
$$BCNF$$ definition
D
$$3$$ $$NF$$ definition
3
GATE CSE 2001
+2
-0.6
$$R(A,B,C,D)$$ is a relation. Which of the following does not have a lossless-join, dependency preserving $$BCNF$$ decomposition?
A
$$A \to B,\,B \to CD$$
B
$$A \to B,\,B \to C.\,C \to D$$
C
$$AB \to C,\,C \to AD$$
D
$$A \to BCD$$
4
GATE CSE 2000
+2
-0.6
Given the following relation instance
\eqalign{ & X\,\,\,\,\,Y\,\,\,\,\,Z \cr & \,\,1\,\,\,\,\,\,4\,\,\,\,\,\,2 \cr & \,\,1\,\,\,\,\,\,5\,\,\,\,\,\,3 \cr & \,\,1\,\,\,\,\,\,6\,\,\,\,\,\,3 \cr & \,\,3\,\,\,\,\,\,2\,\,\,\,\,\,2 \cr}

Which of the following functional dependencies are satisfied by the instance?

A
$$XY \to Z$$ and $$Z \to Y$$
B
$$YZ \to X$$ and $$Y \to Z$$
C
$$YZ \to X$$ and $$X \to Z$$
D
$$XZ \to Y$$ and $$Y \to X$$
GATE CSE Subjects
Discrete Mathematics
Programming Languages
Theory of Computation
Operating Systems
Digital Logic
Computer Organization
Database Management System
Data Structures
Computer Networks
Algorithms
Compiler Design
Software Engineering
Web Technologies
General Aptitude
EXAM MAP
Joint Entrance Examination