Database Management System
Er Diagrams
Marks 1Marks 2
Functional Dependencies and Normalization
Marks 1Marks 2
Structured Query Language
Marks 1Marks 2
Relational Algebra
Marks 1Marks 2
Transactions and Concurrency
Marks 1Marks 2
File Structures and Indexing
Marks 1Marks 2
1
GATE CSE 2012
MCQ (Single Correct Answer)
+2
-0.6
Consider the following relations A, B and C:
A
ID Name Age
12 Arun 60
15 Shreya 24
99 Rohit 11

B
ID Name Age
15 Shreya 24
25 Hari 40
98 Rohit 20
99 Rohit 11

C
ID Phone Area
10 2200 02
99 2100 01

How many tuples does the result of the following relational algebra expression contain? Assume that the schema of A ∪ B is the same as that of A. $$(A\cup B)\bowtie _{A.Id > 40 \vee C.Id < 15} C$$

A
7
B
4
C
5
D
9
2
GATE CSE 2011
MCQ (Single Correct Answer)
+2
-0.6
Consider a relational table r with sufficient number of records, having attributes A1, A2,....., An and let 1 $$ \le $$ p $$ \le $$ n. Two queries Q1 and Q2 are given below.

$$Q1: \pi_{A_1, \dots ,A_p} \left(\sigma_{A_p=c}\left(r\right)\right)$$ where is a constant

$$Q2: \pi_{A_1, \dots ,A_p} \left(\sigma_{c_1 \leq A_p \leq c_2}\left(r\right)\right)$$ where c1 and c2 are constants

The database can be configured to do ordered indexing on Ap or hashing on Ap. Which of the following statements is TRUE?

A
Ordered indexing will always outperform hashing for both queries
B
Hashing will always outperform ordered indexing for both queries
C
Hashing will outperform ordered indexing on Q1, but not on Q2
D
Hashing will outperform ordered indexing on Q2, but not on Q1
3
GATE CSE 2010
MCQ (Single Correct Answer)
+2
-0.6
The following functional dependencies hold for relations R(A, B, C) and S(B, D, E): $$$\eqalign{ & B \to A \cr & A \to C \cr} $$$

The relation R contains 200 tuples and the relation S contains 100 tuples. What is the maximum number of tuples possible in the natural join R $$\Join$$ S?

A
100
B
200
C
300
D
2000
4
GATE CSE 2008
MCQ (Single Correct Answer)
+2
-0.6
Let R and S be two relations with the following schema

R (P, Q, R1, R2, R3)

S (P, Q, S1, S2)

Where {P, Q} is the key for both schemas. Which of the following queries are equivalent?
I. $$\Pi_P \left(R \bowtie S\right)$$
II. $$\Pi_P \left(R\right) \bowtie \Pi_P\left(S\right)$$
III. $$\Pi_P \left(\Pi_{P, Q} \left(R\right) \cap \Pi_{P,Q} \left(S\right) \right)$$
IV. $$\Pi_P \left(\Pi_{P, Q} \left(R\right) - \left(\Pi_{P,Q} \left(R\right) - \Pi_{P,Q} \left(S\right)\right)\right)$$
A
Only I and II
B
Only I and III
C
Only I, II and III
D
Only I, III and IV
GATE CSE Subjects
Theory of Computation
Operating Systems
Algorithms
Digital Logic
Database Management System
Data Structures
Computer Networks
Software Engineering
Compiler Design
Web Technologies
General Aptitude
Discrete Mathematics
Programming Languages
Computer Organization