A collection of instructions that performs a single logical function is called ____________

A. Transaction
B. Operation
C. Function
D. All of the mentioned

A terminated transaction that has completed its execution successfully is ____________ otherwise it is __________

A. Committed, destroyed
B. Aborted, destroyed
C. Committed, aborted
D. None of the mentioned

The state of the data accessed by an aborted transaction must be restored to what it was just before the transaction started executing. This restoration is known as ________ of transaction.

A. Safety
B. Protection
C. Roll €? back
D. Revert €? back

Write ahead logging is a way ____________

A. To ensure atomicity
B. To keep data consistent
C. That records data on stable storage
D. All of the mentioned

In the write ahead logging a _____________ is maintained.

A. A memory
B. A system
C. A disk
D. A log record

An actual update is not allowed to a data item ____________

A. Before the corresponding log record is written out to stable storage
B. After the corresponding log record is written out to stable storage
C. Until the whole log record has been checked for inconsistencies
D. All of the mentioned

The undo and redo operations must be _________ to guarantee correct behaviour, even if a failure occurs during recovery process.

A. Idempotent
B. Easy
C. Protected
D. All of the mentioned

Explanation: Idempotent – Multiple executions of an operation have the same result as does one execution.

The system periodically performs checkpoints that consists of the following operation(s) ____________

A. Putting all the log records currently in main memory onto stable storage
B. Putting all modified data residing in main memory onto stable storage
C. Putting a log record onto stable storage
D. All of the mentioned

Consider a transaction T1 that committed prior to checkpoint. The record appears in the log before the record. Any modifications made by T1 must have been written to the stable storage either with the checkpoint or prior to it. Thus at recovery time ____________

A. There is a need to perform an undo operation on t1
B. There is a need to perform a redo operation on t1
C. There is no need to perform an undo and redo operation on t1
D. All of the mentioned

Serializable schedules are ones where ____________

A. Concurrent execution of transactions is equivalent to the transactions executed serially
B. The transactions can be carried out one after the other
C. A valid result occurs after execution transactions
D. None of the mentioned