ICTDBS-Topic3 Quizz1

Question: Isolation of the transactions is achieved by:

• Avoiding simultaneous transactions.

• Storing updates permanently.

• Preventing system failure.

• Concurrency control.

Answer explanation

Isolation of transactions in a database is achieved through concurrency control, which ensures that multiple transactions can execute concurrently without interfering with each other, maintaining data consistency and integrity.

Database transaction durability ensures that in the event of a system failure, a transaction is:

• Not lost once it has been committed.

• Completed uninterrupted.

• Reversed before it is executed.

• Saved before the failure occurs.

Answer explanation

Durability property of a database transaction ensures that once a transaction is committed, its changes become permanent and will not be lost, even in the event of a system failure.

Which property of database transactions creates an illusion that only one transaction is executed in the system, despite multiple transactions being executed in parallel?

• Atomicity

• Consistency

• Isolation

• Durability

Answer explanation

The isolation property of a database transaction ensures that each transaction is executed as if it is the only transaction in the system, creating an illusion of isolation from other concurrent transactions.

All Oracle transactions obey the basic properties of a database transaction. What is the name of the following property?

"All tasks of a transaction are performed or none of them are. There are no partial transactions."

• Atomicity

• Durability

• Consistency

• Isolation

Answer explanation

The property described in the statement is Atomicity, which ensures that a transaction is treated as an atomic unit, and all its operations are executed together or none are executed at all.

To ensure integrity of the data, a database system should ensure transactions to possess certain properties. The property that makes sure that "either all instructions executed successfully or none of them are" is called:

• Atomicity

• Consistency

• Isolation

• Durability

Answer explanation

Atomicity is the property that ensures that all the instructions of a transaction are executed successfully or none of them are executed, which helps avoid inconsistencies caused