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Objective Type Set
Online MCQ Assignment
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1. I and J are _________ if they are operations by different transactions on the same data item, and at least one of them is a write operation.
a) Conflicting
b) Overwriting
c) Isolated
d) Durable

Answer: a [Reason:] I and J are conflicting if they are operations by different transactions on the same data item, and at least one of them is a write operation.

2. If a schedule S can be transformed into a schedule S’ by a series of swaps of non-conflicting instructions, then S and S’ are
a) Non conflict equivalent
b) Equal
c) Conflict equivalent
d) Isolation equivalent

Answer: c [Reason:] If a schedule S can be transformed into a schedule S’ by a series of swaps of non-conflicting instructions, then S and S’ are conflict equivalent. Not all serial schedules are conflict equivalent to each other.

3. A schedule is __________ if it is conflict equivalent to a serial schedule.
a) Conflict serializable
b) Conflicting
c) Non serializable
d) None of the mentioned

Answer: a [Reason:] A schedule is conflict serializable if it is conflict equivalent to a serial schedule. The concept of conflict equivalence leads to the concept.

4. The set of ________ in a precedence graph consists of all the transactions participating in the schedule
a) Vertices
b) Edges
c) Directions
d) None of the mentioned

Answer: a [Reason:] The set of vertices in a precedence graph consists of all the transactions participating in the schedule. Precedence graph is a simple and efficient way of determining conflict serializability of the schedule.

5. A ___________of the transactions can be obtained by finding a linear order consistent with the partial order of the precedence graph.
a) Serializability order
b) Direction graph
c) Precedence graph
d) Scheduling scheme

Answer: a [Reason:] A Serializability order of the transactions can be obtained by finding a linear order consistent with the partial order of the precedence graph. This process is called as topological sorting.

6. State true or false: If I = read(Q) and J = read(Q) then the order of I and J does not matter.
a) True
b) False

Answer: a [Reason:] If I = read(Q) and J = read(Q) then the order of I and J does not matter because both I and J are read operations on the query.

7. State true or false: If I = read(Q) and J = write(Q) then the order of I and J does not matter.
a) True
b) False