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Recent questions tagged transactions

1 vote
1 answer
1
Consider thw following schedules :- S1 :- W1(A) W2(A) W1(B) W2(B) S2:- W1(A) R2(A) W2(A) W2(B) W1(B) Assume that schedule S1 is failed after performing W1(B). Which of the following options are true? a.) S1 and S2 has lost update problem and WW ... free from lost update problem and WW problem c) S1 has WW problem and S2 has lost update problem d) S1 has lost update problem and s2 has WW problem
asked Jul 16, 2017 in Databases rahul sharma 5 487 views
2 votes
0 answers
2
True / false? 1. Serial schedules don't have any conflicting pairs. 2. Serializable schedules don't have any conflicting pairs
asked Jul 16, 2017 in Databases rahul sharma 5 239 views
4 votes
1 answer
3
Consider thw following transactions:- T1 :- r1(A) w1(A) r1(B) w1(B) T1 :- r2(A) w2(A) r2(B) w2(B) a) Number of schedules serializable as t1->t2? b) Number of schedules serializable as t2->t1?
asked Jul 12, 2017 in Databases rahul sharma 5 582 views
9 votes
2 answers
4
Number of schedules view equal to following schedule :- r1(A), w1(B), r2(A), w2(B), r3(A), w3(B)
asked Jul 10, 2017 in Databases rahul sharma 5 4.7k views
10 votes
5 answers
5
ACID properties of a transactions are Atomicity, consistency, isolation, database Atomicity, consistency, isolation, durability Atomicity, consistency, integrity, durability Atomicity, consistency, integrity, database
asked May 7, 2017 in Databases sh!va 2.7k views
6 votes
5 answers
6
Which of the following concurrency control protocol ensures both conflict and free from deadlock? , Time stamp ordering 2 Phase locking Both (a) and (b) None of the above
asked May 7, 2017 in Databases sh!va 3.4k views
1 vote
3 answers
7
Consider the following schedules: S1: W2(x), W1(x), R3(x), R1(x), W2(y), R3(y), R3(z), R2(x) S2: R3(z), W2(x), W2(y), R1(x), R3(x), R2(z), R3(y), W1(x) S3: R2(z), W2(x), W2(y), W1(x), R1(x), R3(x), R3(z), R3(y) Which one of the above schedules are conflict equivalent?
asked Apr 17, 2017 in Databases Ml_Nlp 715 views
1 vote
1 answer
8
What is the difference between Pessimistic time stamp ordering and optimistic time stamp ordering.
asked Mar 17, 2017 in Databases LavTheRawkstar 1.4k views
0 votes
1 answer
9
What is the advantage and drawback of Multiversion Timestamp ordering in comparison with ordering Time stamp ordering? anyone please also explain what is this multiversion Timestamp ordering and what is the Timestamp ordering in simple words please?
asked Mar 17, 2017 in Databases LavTheRawkstar 1.5k views
0 votes
0 answers
10
In two phase Commit Protocol,why can blocking be completely eliminated even when participants elect a new Coordinator ?
asked Mar 17, 2017 in Databases LavTheRawkstar 405 views
1 vote
2 answers
11
Essential differences in the Lock based Protocols and Time-stamp based proctols?
asked Mar 17, 2017 in Databases LavTheRawkstar 2.1k views
1 vote
2 answers
12
Somebody please explain this i am not able to understand please given an example of transaction or explain in hindi what the question and answer is please explain somebody please Here i am posting the Entire Question with some Multiple Choices and a Perfect Example now please somebody please explain which choice is correct and which is wrong I am not able to understand it.
asked Mar 16, 2017 in Databases LavTheRawkstar 624 views
90 votes
16 answers
13
Two transactions $T_1$ and $T_2$ are given as $T_1:r_1(X)w_1(X)r_1(Y)w_1(Y)$ $T_2:r_2(Y)w_2(Y)r_2(Z)w_2(Z)$ where $r_i(V)$ denotes a $\textit{read}$ operation by transaction $T_i$ on a variable $V$ and $w_i(V)$ denotes a $\textit{write}$ operation by transaction $T_i$ on a variable $V$. The total number of conflict serializable schedules that can be formed by $T_1$ and $T_2$ is ______
asked Feb 14, 2017 in Databases Madhav 35.4k views
2 votes
1 answer
14
I)All schedules that are allowed under 2PL are also allowed under Timestamp?? Is vice versa true?? II)Plz explain by giving example. I have read that there are schedules that are allowed under 2PL but not under Timestamp and vice versa, but need example. ... in Timestamp??? IV) Are all view serializable allowed under Timestamp(Thomas write rule)??? Explanation along with example would be helpful.
asked Feb 4, 2017 in Databases Rahul Jain25 998 views
1 vote
2 answers
15
IS CONSERVATIVE 2PL ALSO RIGOROUS?? WHEN WE SAY THAT A TRANSACTION FOLLOWS CONSERVATIVE TWO PHASE LOCKING, DOES IT AUTOMATICALLY ALSO IMPLY RIGOROUS 2PL??
asked Jan 31, 2017 in Databases sushmita 186 views
1 vote
2 answers
17
S: R1(A), R3(D), W1(B), R2(B), R4(B), W2(C), R5(C), W4(E), R5(E), W5(B) Number of serial schedules which are view equal to above S are __. Polygraph that I drew:
asked Jan 30, 2017 in Databases sivajagsa 630 views
1 vote
2 answers
18
Whether the given schedule is conflict serializable or view serializable or none.
asked Jan 29, 2017 in Databases Kai 254 views
7 votes
3 answers
19
$S: R_1(A),R_2(B),W_2(A),W_3(C),R_4(C),R_3(A),W_3(B),R_4(A),W_2(B),W_4(B),W_3(A)$ View serializable or not?
asked Jan 28, 2017 in Databases Supremo 1k views
1 vote
1 answer
20
Do commit operations matter while checking serilizability?If yes why?
asked Jan 28, 2017 in Databases Gate Madrista 211 views
0 votes
1 answer
22
Here T1 T2 T4 T5 will come in this order only and for T3 we have 5 positions So number of schedules will be 5 which are view eq to given schedule. But ans given is 10
asked Jan 26, 2017 in Databases vaishali jhalani 94 views
1 vote
1 answer
23
Consider the following schedule S : r1(A) w2(A) r3(A) w4(A) r5(A) w6(A) The number of schedules equal to given schedule(s) which not conflict equal to schedule(s) are _______.
asked Jan 23, 2017 in Databases Çșȇ ʛấẗẻ 117 views
1 vote
1 answer
24
1 vote
4 answers
25
I know that every schedule produced by the Timestamp-based protocol is conflict serializable. But is vice versa is true? Means is all conflict serializable schedules produced by timestamp based protocol ?
asked Jan 21, 2017 in Databases lifeisshubh 850 views
0 votes
1 answer
26
Consider the following transaction T1 T2 T3 R(A) W(A) commit W(A) commit W(A) commit Which of the following is TRUE regarding above transaction? (1) Transaction is view serializable since it has a view-equivalent serial schedule < T1, T2 T3 > (2) Transaction ... a view-equivalent serial schedule < T3, T2 T1 > (4) Transaction is not serializable Your Answer: 3 Correct Answer: 1 Status: incorrect
asked Jan 19, 2017 in Databases vishwa ratna 150 views
1 vote
2 answers
27
0 votes
0 answers
28
Which of the following is true? In 2PL protocol if all exclusive lock are acquired by transactions in only increasing order of their addresses then 2PL protocol is deadlock free. In 2PL protocol if all exclusive lock are acquire by transaction in only increasing order of ... when they are talking about the address it should be the address of resources right? in that case 4th should be the option
asked Jan 17, 2017 in Databases Pankaj Joshi 180 views
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