Podcast
Questions and Answers
What happens to a transaction when it enters the failed state in a database system?
What happens to a transaction when it enters the failed state in a database system?
- It is rolled back and enters the aborted state. (correct)
- It proceeds with normal execution.
- It is immediately restarted as a new transaction.
- It remains in the failed state indefinitely.
Under what circumstances can a failed transaction be restarted in a database system?
Under what circumstances can a failed transaction be restarted in a database system?
- If the failure was due to a hardware or software error not created through the internal logic of the transaction. (correct)
- If the failure was due to bad input data.
- If the failure was due to not finding desired data in the database.
- If the failure was due to an external logical error.
Why might a database system decide to kill a transaction?
Why might a database system decide to kill a transaction?
- Due to errors in hardware causing the failure.
- Due to network issues preventing data retrieval from the database.
- Due to bad input data received during the transaction.
- Due to internal logical errors that require rewriting the application program. (correct)
Why is it essential to be cautious when dealing with observable external writes in a database system?
Why is it essential to be cautious when dealing with observable external writes in a database system?
What does it mean for a transaction to be considered a new transaction when restarted in a database system?
What does it mean for a transaction to be considered a new transaction when restarted in a database system?
Why do most systems allow observable external writes only after a transaction has entered the committed state?
Why do most systems allow observable external writes only after a transaction has entered the committed state?
What property in databases ensures that transactions either fully complete or have no effect at all?
What property in databases ensures that transactions either fully complete or have no effect at all?
Which property refers to the requirement that transactions must operate independently without interference from other concurrently executing database statements?
Which property refers to the requirement that transactions must operate independently without interference from other concurrently executing database statements?
What property ensures that transactions persist across system crashes in databases?
What property ensures that transactions persist across system crashes in databases?
In database systems, which property is violated if a system 'forgets' about a transaction after a crash?
In database systems, which property is violated if a system 'forgets' about a transaction after a crash?
What is the term used to describe the 'all-or-none' property in databases which guarantees that transactions are indivisible?
What is the term used to describe the 'all-or-none' property in databases which guarantees that transactions are indivisible?
Which database property ensures that transactions execute without interference from other concurrent operations?
Which database property ensures that transactions execute without interference from other concurrent operations?
What happens if the system fails after a transaction has entered the committed state but before completing external writes?
What happens if the system fails after a transaction has entered the committed state but before completing external writes?
What is a possible issue when handling external writes for dispensing cash at an automated teller machine?
What is a possible issue when handling external writes for dispensing cash at an automated teller machine?
What action needs to be taken if the database system crashes just after a booking transaction commits over the Web?
What action needs to be taken if the database system crashes just after a booking transaction commits over the Web?
How is atomicity in databases related to handling system failures?
How is atomicity in databases related to handling system failures?
Why is it important for applications to be designed such that users can verify the success of their transactions after a system failure?
Why is it important for applications to be designed such that users can verify the success of their transactions after a system failure?
In the context of database recovery systems, what does durability refer to?
In the context of database recovery systems, what does durability refer to?
