Questions tagged [conflict-serializability]
5 questions
1
vote
2 answers
Does two phase locking actually prevent lost updates?
Two phase locking is claimed to be a solution for ensuring serial execution. However, I'm not sure how it adequately solves the lost update problem during a read-modify-write cycle. I may be overlooking / misunderstanding the locking mechanism…
linstantnoodles
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Unrepeatable read or something else?
I'm going over transaction management in DBMS, specifically conflict serializability. I know that
T1_R(a), T2_R(b), T1_R(a)
would be considered an unrepeatable read. But would
T1_R(a), T2_W(a)
be considered an unrepeatable read? And if not, what…
daniel
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Is this considered a cycle?
Regarding precedence graphs and conflict serializability, is it considered a cycle when two nodes are connected by a cycle but each arrow refers to a different object? For example:
Thanks!
daniel
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1 answer
How to determine the whether the transaction is conflict-serializable or not?
I've the following question:
read(T1, x)
read(T2, x)
write(T1, x)
write(T2, x)
commit(T1)
commit(T2)
State whether the schedule is conflict-serializable, recoverable and avoids cascading abort?
I approach the problem…
Ahmet
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1 answer
How do we perform swap operation in conflict-serializability?
Assume I have the following concurrent transactions:
----------------------
|Ti | Tj |
----------------------
| write(Q) | |
----------------------
| | read(Q) |
----------------------
| read(Q) | …
Ahmet
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