18 Questions
What is the primary objective of serializability?
To ensure that concurrent transactions do not interfere with each other.
What is the purpose of applying rule 6 in creating a graph to determine serializability?
To determine the view serializability of a schedule
What happens if two transactions only read a data item?
They do not conflict and the order of execution is not important.
What is the result of serial execution?
The database state is consistent and correct.
Why do DBMSs not test for the serializability of a schedule?
Because it is impractical to test for serializability
What is a correct nonserial schedule called?
Serializable.
What is the purpose of using protocols that are known to produce serializable schedules?
To ensure the consistency of the database
What is the requirement of the atomicity property in the event of a transaction failure?
To undo the effects of the transaction
Why is it essential to guarantee serializability of concurrent transactions?
To prevent inconsistency from transactions interfering with one another.
What is the implication of the durability property on a committed transaction?
Its changes cannot be undone without running another, compensating, transaction
What is important in the ordering of read and write operations?
The order of execution is only important when one transaction writes and another reads the same data item.
What is the relationship between serializability and recoverability?
Recoverability is a subset of serializability
What is a necessary condition for two schedules to be considered view equivalent?
They must consist of the same operations from n transactions.
If a transaction Ti reads the initial value of a data item x in schedule S1, what must it do in schedule S2?
It must also read the initial value of x.
What is true about every conflict serializable schedule?
It is view serializable.
What is a characteristic of a view serializable schedule that is not conflict serializable?
It contains one or more blind writes.
What is the relationship between view serializability and conflict serializability?
Every conflict serializable schedule is view serializable.
What is the purpose of the concept of view serializability?
To provide a less restrictive definition of serializability.
Learn about the importance of managing concurrency in databases to prevent inconsistencies and incorrect results. Serial execution ensures consistency and correctness.
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