1

### GATE CSE 2015 Set 2

Consider the following transaction involving two bank accounts x and y.
read (x) ; x: = x - 50; write (x); read (y); y: = y + 50;   write (y)

The constraint that the sum of the accounts x and y should remain constant is that of

A
Atomicity
B
Consistency
C
Isolation
D
Durability
2

### GATE CSE 2015 Set 2

Consider a simple checkpointing protocol and the following set of operations in the log.

(start, $T4$); (write, $T4, y, 2, 3$); (start, $T1$); (commit, $T4$); (write, $T1, z, 5, 7$);
(checkpoint);
(start, $T2$); (write, $T2, x, 1, 9$); (commit, $T2$); (start, $T3$), (write, $T3, z, 7, 2$);

If a crash happens now and the system tries to recovver using both undo and redo operations, what are the contents of the undo list and the redo list?

A
Undo: $T3,T1;$ Redo: $T2$
B
Undo: $T3,T1;\,{\mathop{\rm Re}\nolimits} do:T2,T4$
C
Undo: none; Redo: $T2,T4,T3,T1$
D
Undo: $T3,T1,T4;\,\,$ Redo : $T2$
3

### GATE CSE 2015 Set 2

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?
A
$R$ contains $a, b, e, f, g$ but not $c, d.$
B
$R$ contains all of $a, b, c, d, e, f, g.$
C
$R$ contains $e, f, g$ but not $a, b.$
D
$R$ contains $e$ but not $f, g.$
4
Numerical

### GATE CSE 2015 Set 2

The minimum number of $JK$ flip-flops required to construct a synchronous counter with the count sequence $\left( {0,0,1,1,2,2,3,3,0,0,...} \right)$ is ____________.

### Paper Analysis of GATE CSE 2015 Set 2

Subject NameTotal Questions
Algorithms5
Compiler Design3
Computer Networks6
Computer Organization4
Data Structures3
Database Management System4
Digital Logic3
Discrete Mathematics12
Operating Systems4
Programming Languages3
Software Engineering3
Theory of Computation4
Web Technologies1