Concurrency Control Techniques Questions and Answers

Multiple Choice Questions and Answers

Question 1 : To synchronize the concurrent accessing of database items, we use 

(a) Transactions
(b) States
(c) Locks
(d) None of the above

Answer : (cb)

Question 2 : When a transaction never progresses then we say that it is

(a) Aborted
(b) Starved
(c) Shared
(d) Locked

Answer : (b)

Question 3 : During pessimistic approach, the order of operation execution is

(a) Read, Validate, Compute, Write
(b) Validate, Read, Compute, Write
(c) Validate, Compare, Read, Write
(d) None of the above

Answer : (b)

Question 4 : A phase during which all locks are requested is known as a 

(a) Growing phase
(b) Shrinking phase
(c) Aborted phase
(d) None of the above

Answer : (a)

Question 5 : No more lock requests can be asked for in

(a) Growing phase
(b) Shrinking phase
(c) Aborted phase
(d) None of the above

Answer : (bc)

Question 6 : The point in the schedule where the transaction has obtained its final lock is known as 

(a) Deadlock
(b) Commit point
(c) Lock point
(d) None of the above

Answer : (c)

Question 7 : 2PL protocol suffers from:

(a) Deadlock
(b) Cascading Roll back
(c) Both (a) and (b)
(d) None of the above

Answer : (c)

Question 8 : A protocol in which we must have a prior knowledge of the order in which the database items will be assessed is

(a) Tree protocol
(b) OSI protocol
(c) TCP/IP
(d) None of the above

Answer : (a)

Question 9 : Timestamp has a property of

(a) Monotonicity
(b) Irreducibility
(c) Atomicity
(d) None of the above

Answer : (a)

Question 10 : Timestamps can be implemented by using a 

(a) System clock
(b) Logical counter
(c) Both ‘a’ and ‘a’
(d) None of the above

Answer : (c)

Question 11 : Deadlock frequency is given by

(a) Square-root of degree of multiprogramming
(b) Fourth power of transaction size
(c) Fifth power of transaction size
(d) None of the above

Answer : (b)

Question 12 : By granularity, we mean

(a) Size of data item being locked
(b) Size of locks
(c) Size of a transaction
(d) None of the above

Answer : (a)

Question 13 : The major factor for concurrency control is 

(a) Granularity
(b) Locking
(c) Time stamping
(d) None of the above

Answer : (a)

Question 14 : The assumption that hardware errors and bugs in the software bring the system to halt but do not corrupt the non-volatile storage contents is known as

(a) Lock point
(b) Fail-stop assumption
(c) Single fault assumption
(d) None of the above

Answer : (b)

Question 15 : Disks and tapes are the examples of

(a) Volatile storage
(b) Non-volatile storage
(c) Stable storage
(d) None of the above

Answer : (b)

DBMS Questions and Answers