GATE CSE 1999 | Relational Algebra Question 33 | Database Management System

GATE CSE 1999

MCQ (Single Correct Answer)

-0.3

The relational algebra expression equivalent to the following tuple calculus expression:

$$\left\{ {t|t \in r \wedge \left( {t\left[ A \right] = 10 \wedge t\left[ B \right] = 20} \right)} \right\}$$ is:

$${\sigma _{\left( {A = 10 \vee B = 20} \right)}}\left( r \right)$$

$${\sigma _{\left( {A = 10} \right)}}\left( r \right) \cup {\sigma _{\left( {B = 20} \right)}}\left( r \right)$$

$${\sigma _{\left( {A = 10} \right)}}\left( r \right) \cap {\sigma _{\left( {B = 20} \right)}}\left( r \right)$$

$${\sigma _{\left( {A = 10} \right)}}\left( r \right) - {\sigma _{\left( {B = 20} \right)}}\left( r \right)$$

GATE CSE 1994

True or False

-0

An instance of a relational scheme R(A, B, C) has distinct values for attribute A. Can you conclude that A is a candidate key for R?

TRUE

FALSE

GATE CSE 1994

True or False

-0

Give a relational algebra expression using only the minimum number of operators from $$\left( { \cup ,\, - } \right)$$ which is equivalent to $$R \cap S$$.

TRUE

FALSE

GATE CSE Subjects

Theory of Computation

Undecidability Finite Automata and Regular Language Push Down Automata and Context Free Language Recursively Enumerable Language and Turing Machine

Operating Systems

Process Concepts and Cpu Scheduling Synchronization and Concurrency Deadlocks Memory Management File System IO and Protection

Algorithms

Complexity Analysis and Asymptotic Notations Searching and Sorting Divide and Conquer Method Greedy Method Dynamic Programming P and NP Concepts

Digital Logic

K Maps Boolean Algebra Combinational Circuits Number Systems Sequential Circuits

Database Management System

Structured Query Language Transactions and Concurrency Functional Dependencies and Normalization Relational Algebra File Structures and Indexing Er Diagrams

Data Structures

Trees Hashing Arrays Linked List Graphs Stacks and Queues

Computer Networks

Network Security Data Link Layer and Switching Application Layer Protocol Network Layer Routing Algorithm Concepts of Layering Lan Technologies and Wi-Fi TCP UDP Sockets and Congestion Control

Software Engineering

Compiler Design

Lexical Analysis Parsing Syntax Directed Translation Code Generation and Optimization

Web Technologies

General Aptitude

Numerical Ability Logical Reasoning Verbal Ability

Discrete Mathematics

Graph Theory Set Theory & Algebra Combinatorics Mathematical Logic Probability Linear Algebra Calculus

Programming Languages

Basic of Programming Language Function and Recursion Pointer and Structure in C

Computer Organization

Computer Arithmetic Memory Interfacing Machine Instructions and Addressing Modes IO Interface Pipelining Alu Data Path and Control Unit Secondary Memory