1
GATE CSE 2012
MCQ (Single Correct Answer)
+2
-0.6
Suppose a circular queue of capacity (n – 1) elements is implemented with an array of n elements. Assume that the insertion and deletion operations are carried out using REAR and FRONT as array index variables, respectively. Initially, REAR = FRONT = 0. The conditions to detect queue full and queue empty are
A
full: (REAR+1)
mod n == FRONT
empty: REAR == FRONT
B
full: (REAR+1)
mod n == FRONT
empty: (FRONT+1)
C
full: REAR == FRONT
empty: (REAR + 1)
mod n == FRONT
D
full: (FRONT+1)
mod n == REAR
empty: REAR == FRONT
2
GATE CSE 2012
MCQ (Single Correct Answer)
+2
-0.6
Let G be a weighted graph with edge weights greater than one and G' be the graph constructed by squaring the weights of edges in G. Let T and T' be the minimum spanning trees of G and G' respectively, with total weights t and t'. Which of the following statements is TRUE?
A
T' = T with total weight t' = t2
B
T' = T with total weight t' < t2
C
T' =! T but total weight t' = t2
D
None of these
3
GATE CSE 2012
MCQ (Single Correct Answer)
+1
-0.3
Which of the following statements are TRUE about an SQL query?

P: An SQL query can contain a HAVING clause even if it does not have a GROUP BY clause
Q: An SQL query can contain a HAVING clause only if it has a GROUP BY clause
R: All attributes used in the GROUP BY clause must appear in the SELECT clause
S: Not all attributes used in the GROUP BY clause need to appear in the SELECT clause

A
P and R
B
P and S
C
Q and R
D
Q and S
4
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