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Recent questions tagged concurrency

2 votes
1 answer
2
Gate Wallah Study material
Please help with the minimum value. Problem is from the gate wallah study handout.
Please help with the minimum value. Problem is from the gate wallah study handout.
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1 votes
2 answers
4
Is a Serial Schedule always Recoverable?
Is only conflict serializable schedules are recoverable? Or both view as well as conflict serializable schedules are recoverable? I have been seeing different answers in different forum.
Is only conflict serializable schedules are recoverable?Or both view as well as conflict serializable schedules are recoverable?I have been seeing different answers in di...
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0 votes
0 answers
5
concurrency control
question about concurrency control methods
question about concurrency control methods
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1 votes
2 answers
9
Gate 2019- minimum D value in OS concurrent process question
Why the value of D is 80 in concurrent process question and not 0? The question didn't mention that each statement take 3 instruction to execute so why assume that?
Why the value of D is 80 in concurrent process question and not 0? The question didn't mention that each statement take 3 instruction to execute so why assume that?
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2 votes
0 answers
10
Self doubt, 2PL
Is different 2 phase locking a subset of each other? For example, if the schedule is Strict 2PL then it will also be simple 2PL. Something like a 2PL is a subset of Strict 2PL is a subset of rigorous 2PL.
Is different 2 phase locking a subset of each other? For example, if the schedule is Strict 2PL then it will also be simple 2PL.Something like a 2PL is a subset of Strict...
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2 votes
0 answers
13
Self Doubt: Is this schedule conflict Serializable?
My question, does abort in T2 makes this schedule conflict serializable? as the effect of T2 will be null. T1: Rx T2: Wx T1: Wx T2: ABORT T1: COMMIT Rx – read item x. Wx – write item x.
My question, does abort in T2 makes this schedule conflict serializable? as the effect of T2 will be null. T1: Rx T2: Wx T1: Wx T2: ABORT T1: COMMITRx – read item x.Wx...
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1 votes
0 answers
14
TRANSACTIONS
ANY EXAMPLE OF AN SCHEDULE WHICH IS RECOVERABLE BUT NOT CASCADLESS.?
ANY EXAMPLE OF AN SCHEDULE WHICH IS RECOVERABLE BUT NOT CASCADLESS.?
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1 votes
1 answer
15
[Personal Doubt] View Serializability
Is every serializable schedule view serializable?, or like conflict serializable, there could be a serializable schedule which isn’t view serializable?
Is every serializable schedule view serializable?, or like conflict serializable, there could be a serializable schedule which isn’t view serializable?
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16
GA Test series
pls explain why C is correct not A? isn’t every schedule that is supported by 2PL conflict serializable?
pls explain why C is correct not A?isn’t every schedule that is supported by 2PL conflict serializable?
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18
Raghuramkrishnan
T1: R(X), T2: W(X), T2: commit, T1: W(X), T1: commit, T3: R(X), T3: commit is this allowed in Thomas write rule? if yes then what will be the serial order
T1: R(X), T2: W(X), T2: commit, T1: W(X), T1: commit, T3: R(X), T3: commitis this allowed in Thomas write rule?if yes then what will be the serial order
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1 votes
1 answer
19
2PL Doubt
T1: W(X), T2: R(Y), T1: R(Y), T2: R(X) does 2PL protocol allows it? T1 T2 L-X(X) W(X) L-S(Y) R(Y) U(X) L-S(Y) R(Y) L-S(X) R(X) here T2 is granted lock on X as T1 enters shrinking phase as no exclusive locks are held on X is my solution correct?
T1: W(X), T2: R(Y), T1: R(Y), T2: R(X)does 2PL protocol allows it? T1 T2L-X(X)W(X)L-S(Y)R(Y)U(X) L-S(Y)R(Y)L-S(X)R(X)here T2 is granted lock on X as T1 enters sh...
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0 votes
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20
#easy book
T1 T2 R(X) W(X) W(X) aborts commit find conflict serializability,view serializability, recoverable,cascadeless and strict schedule
T1T2R(X) W(X)W(X) abortscommit find conflict serializability,view serializability, recoverable,cascadeless and strict schedule
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1 votes
0 answers
21
Syllabus of Database management system
Are following part of gate syllabus for dbms? 1-Validation Based protocols 2-multiversion schemes 3-snapshot isolation 4-predicate reads(concurrency control) 5-concurrency in index structures.
Are following part of gate syllabus for dbms?1-Validation Based protocols2-multiversion schemes3-snapshot isolation4-predicate reads(concurrency control)5-concurrency in ...
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1 votes
1 answer
25
Cascadeless/ Recoverable
The given schedule: R1 (A) R2 (B) W2 (B) W1(A) W2 (A) Commit2 R1 (C) is revoreable, cascadeless or strict?
The given schedule:R1 (A) R2 (B) W2 (B) W1(A) W2 (A) Commit2 R1 (C)is revoreable, cascadeless or strict?
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1 votes
1 answer
26
Strict and Conservative 2PL
We know, Conservative 2PL is another name of Strict 2PL. But According to Navathe book Conservative 2PL is deadlock free,but Strict 2PL can have deadlock. Then how both could be same??
We know, Conservative 2PL is another name of Strict 2PL. But According to Navathe bookConservative 2PL is deadlock free,but Strict 2PL can have deadlock.Then how both cou...
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