1
GATE CSE 2021 Set 1
MCQ (More than One Correct Answer)
+2
-0.67

Suppose a database system crashes again while recovering from a previous crash. Assume checkpointing is not done by the database either during the transactions or during recovery.

Which of the following statements is/are correct?

A
The same undo and redo list will be used while recovering again.
B
The database will become inconsistent.
C
All the transactions that are already undone and redone will not be recovered again.
D
The system cannot recover any further.
2
GATE CSE 2021 Set 1
MCQ (Single Correct Answer)
+2
-0.67

Let ri(z) and wi(z) denote read and write operations respectively on a data item z by a transaction Ti. Consider the following two schedules.

S1 : r1(x) r1(y) r2(x) r2(y) w2(y) w1(x)

S2 : r1(x) r2(x) r2(y) w2(y) r1(y) w1(x)

Which one of the following options is correct?

A
S1 is conflict serializable, and S2 is not conflict serializable.
B
S1 is not conflict serializable, and S2 is conflict serializable.
C
Both S1 and S2 are conflict serializable.
D
Neither S1 nor S2 is conflict serializable.
3
GATE CSE 2020
MCQ (Single Correct Answer)
+2
-0.67
Consider a schedule of transactions T1 and T2 : GATE CSE 2020 Database Management System - Transactions and Concurrency Question 4 English
Here, RX stands for “Read(X)” and WX stands for “Write(X)”. Which one of the following schedules is conflict equivalent to the above schedule?
A
GATE CSE 2020 Database Management System - Transactions and Concurrency Question 4 English Option 1
B
GATE CSE 2020 Database Management System - Transactions and Concurrency Question 4 English Option 2
C
GATE CSE 2020 Database Management System - Transactions and Concurrency Question 4 English Option 3
D
GATE CSE 2020 Database Management System - Transactions and Concurrency Question 4 English Option 4
4
GATE CSE 2016 Set 2
MCQ (Single Correct Answer)
+2
-0.6
Consider the following database schedule with two transactions, T1 and T2
 S = r2(X); r1(X); r2(Y); w1(X); r1(Y); w2(X); a1; a2

where ri(Z) denotes a read operation by transaction Ti on a variable Z, wi(Z) denotes a write operation by Ti on a variable Z and ai denotes an abort by transaction Ti .

Which one of the following statements about the above schedule is TRUE?

A
S is non-recoverable
B
S is recoverable, but has a cascading abort
C
S does not have a cascading abort
D
S is strict
GATE CSE Subjects
Software Engineering
Web Technologies
EXAM MAP
Medical
NEET
Graduate Aptitude Test in Engineering
GATE CSEGATE ECEGATE EEGATE MEGATE CEGATE PIGATE IN
CBSE
Class 12