Transactions and Concurrency · Database Management System · GATE CSE
Start PracticeMarks 1
GATE CSE 2024 Set 2
Once the DBMS informs the user that a transaction has been successfully completed, its effect should persist even if the system crashes before all its...
GATE CSE 2024 Set 2
Which of the following statements about the Two Phase Locking (2PL) protocol is/are TRUE?
GATE CSE 2021 Set 1
Suppose a database system crashes again while recovering from a previous crash. Assume checkpointing is not done by the database either during the tra...
GATE CSE 2019
Consider the following two statements about database transaction schedules:
I. Strict two-phase locking protocol generates conflict serializable sche...
GATE CSE 2016 Set 1
Which one of the following is NOT a part of the $$ACID$$ properties of database transactions?
GATE CSE 2016 Set 2
Suppose a database schedule $$S$$ involves transactions $${T_1},\,...,\,{T_n}.$$ Construct the precedence graph of $$S$$ with vertices representing th...
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 con...
GATE CSE 2010
Which of the following concurrency control protocols ensure both conflict serializability and freedom from deadlock?
I. 2-phase locking
II. Time-sta...
GATE CSE 2005
Amongst the ACID properties of a transaction, the 'Durability' property requires that the changes made to the database by a successful transaction per...
GATE CSE 2004
Which level of locking provides the highest degree of concurrency in a relational database?
GATE CSE 2003
Which of the following scenarios may lead to an irrecoverable error in a database system?
Marks 2
GATE CSE 2024 Set 1
Consider the following read-write schedule $S$ over three transactions $T_{1}$, $T_{2}$, and $T_{3}$, where the subscripts in the schedule indicate tr...
GATE CSE 2022
Let Ri(z) and Wi(z) denote read and write operations on a data element z by a transaction Ti, respectively. Consider the schedule S with four transact...
GATE CSE 2021 Set 2
Let S be the following schedule of operations of three transactions T1, T2 and T3 in a relational database system:
R2(Y), R1(X), R3(Z), R1(Y), W1(X),...
GATE CSE 2021 Set 1
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...
GATE CSE 2020
Consider a schedule of transactions T1 and T2 :
Here, RX stands for “Read(X)” and WX stands for “Write(X)”. Which one of the following schedules is c...
GATE CSE 2016 Set 1
Consider the following two phase locking protocol. Suppose a transaction $$T$$ accesses (for read or write operations), a certain set of objects $$\le...
GATE CSE 2016 Set 2
Consider the following database schedule with two transactions, T1 and T2
S = r2(X); r1(X); r2(Y); w1(X); r1(Y); w2(X); a1; a2
where ri(Z) ...
GATE CSE 2015 Set 3
Consider the following partial Schedule S involving two transactions $$T1$$ and $$T2.$$ Only the read and the write operations have been shown. The re...
GATE CSE 2015 Set 2
Consider a simple checkpointing protocol and the following set of operations in the log.
(start, $$T4$$); (write, $$T4, y, 2, 3$$); (start, $$T1$$); ...
GATE CSE 2014 Set 3
Consider the transactions T1, T2, and T3 and the schedules S1 and S2 given below.
T1 : r1 (X) ; r1 (Z) ; w1 (X) ; w1 (Z)
T2 : r2 (X) ; r2 (Z) ; w2 (Z...
GATE CSE 2014 Set 2
Consider the following schedule S of transactions T1, T2, T3, T4:
...
GATE CSE 2014 Set 1
Consider the following four schedules due to three transactions (indicated by the subscript) using
read and write on a data item x, denoted by r(x) an...
GATE CSE 2012
Consider the following transactions with data items P and Q initialized to zero:
T1 : read (P) ;
read (Q) ;
if P = 0 then Q : = Q + 1 ;
...
GATE CSE 2010
Consider the following schedule for transactions T1, T2 and T3:
Which one of the schedules below is the correct serialization of the above?...
GATE CSE 2009
Consider two transactions T1 and T2 and four schedules S1, S2, S3, S4 of T1 and T2
as given below:
T1: R1[ x ] W1[ x ] W1[ y ]
T2: R2[ x ] R2[ y ] W...
GATE CSE 2009
Let R and S be relational schemes such that R = { a, b, c } and S = { c }. Now consider the following queries on the database:
I. $$\pi_{R-S}(r) - \pi...
GATE CSE 2008
Consider the following three schedules of transactions T1, T2 and T3. [ Notation: In the following NYO represents the action Y (R for read, W for writ...
GATE CSE 2007
Consider the following schedules involving two transactions. Which one of the following statements is TRUE?
S1: r1(X); r1(Y); r2(Y); r2(X); w2(Y); w1...
GATE CSE 2007
Consider the following two transactions: T1 and T2.
T1: read (A); T2: read (B);
read (B); read (A);
if A...
GATE CSE 2004
Consider the following schedule S of transactions T1 and T2:
Which of the following is TRUE about the schedule S?...
GATE CSE 2003
Consider three data items D1, D2, and D3, and the following execution schedule of transactions T1, T2, and T3. In the diagram, R(D) and W(D) denote th...
GATE CSE 1999
For the schedule given below, which of the following is correct:
...