1

GATE CSE 2018

MCQ (Single Correct Answer)

+2

-0.6

Consider the relations $$r(A, B)$$ and $$s(B, C),$$ where $$s.B$$ is a primary key and $$r.B$$ is a foreign key referencing $$s.B.$$ Consider the query

$$Q:$$ $$\,\,\,\,\,\,\,\,\,$$ $$r$$ $$\,\,\,\,$$ $$\bowtie$$ $$\,\,\,\,$$ $$\left( {{\sigma _{b < 5}}\left( s \right)} \right)$$

Let $$LOJ$$ denote the natural left outer-join operation. Assume that $$r$$ and $$s$$ contain no null values.

Which one of the following queries is NOT equivalent to $$Q$$?

2

GATE CSE 2015 Set 2

MCQ (Single Correct Answer)

+2

-0.6

Consider two relations $${R_1}\left( {A,B} \right)$$ with the tuples $$(1,5), (3,7)$$ and $${R_2}\left( {A,C} \right) = \left( {1,7} \right),\left( {4,9} \right).$$

Assume that $$R(A,B,C)$$ is the full natural outer join of $${R_1}$$ and $${R_2}$$. Consider the following tuples of the form $$(A,B,C): a = (1,5,null),$$ $$b = (1,null,7),$$ $$c = (3, null, 9),$$ $$d = (4,7,null),$$ $$e = (1,5,7),$$ $$f = (3,7,null),$$ $$g = (4,null,9).$$ Which one of the following statements is correct?

Assume that $$R(A,B,C)$$ is the full natural outer join of $${R_1}$$ and $${R_2}$$. Consider the following tuples of the form $$(A,B,C): a = (1,5,null),$$ $$b = (1,null,7),$$ $$c = (3, null, 9),$$ $$d = (4,7,null),$$ $$e = (1,5,7),$$ $$f = (3,7,null),$$ $$g = (4,null,9).$$ Which one of the following statements is correct?

3

GATE CSE 2014 Set 2

MCQ (Single Correct Answer)

+2

-0.6

Consider a join (relation algebra) between relations

**r(R)**and**s(S)**using the nested loop method. There are 3 buffers each of size equal to disk block size, out of which one buffer is reserved for intermediate results. Assuming**size(r(R)) < size(s(S))**, the join will have fewer number of disk block accesses if4

GATE CSE 2014 Set 3

MCQ (Single Correct Answer)

+2

-0.6

Consider the relational schema given below, where

**eId**of the relation**dependent**is a foreign key referring to**empId**of the relation**employee**. Assume that every employee has at least one associated dependent in the dependent relation:**employee ( empId, empName, empAge)**

**dependent ( depId, eId, depName, depAge)**

The above query evaluates to the set of empIds of employees whose age is greater than that of

Questions Asked from Relational Algebra (Marks 2)

Number in Brackets after Paper Indicates No. of Questions

GATE CSE 2021 Set 1 (1)
GATE CSE 2019 (1)
GATE CSE 2018 (1)
GATE CSE 2015 Set 2 (1)
GATE CSE 2014 Set 2 (1)
GATE CSE 2014 Set 3 (1)
GATE CSE 2012 (3)
GATE CSE 2011 (1)
GATE CSE 2010 (1)
GATE CSE 2008 (1)
GATE CSE 2007 (4)
GATE CSE 2005 (1)
GATE CSE 2004 (1)
GATE CSE 2001 (1)
GATE CSE 1998 (1)
GATE CSE 1996 (1)

GATE CSE Subjects

Discrete Mathematics

Programming Languages

Theory of Computation

Operating Systems

Computer Organization

Database Management System

Data Structures

Computer Networks

Algorithms

Compiler Design

Software Engineering

Web Technologies

General Aptitude