56. OCR A Level (H446) SLR10 – 1.3 Transaction processing

What is transaction processing?

• A programming language for databases

• A method for creating databases

• Any information processing divided into indivisible operations called transactions

• A type of database management system

Answer explanation

Transaction processing refers to any information processing divided into indivisible operations called transactions, making it the correct choice.

What must each transaction in a database do?

• Succeed or fail as a complete unit

• Be partially complete

• Only read data

• Only update data

Answer explanation

Each transaction in a database must succeed or fail as a complete unit, ensuring data integrity and consistency.

What does CRUD stand for?

• Create, Run, Update, Disable

• Connect, Read, Use, Delete

• Create, Read, Update, Delete

• Connect, Retrieve, Utilize, Discard

Answer explanation

CRUD stands for Create, Read, Update, Delete. It is a set of basic operations used in database management systems to interact with the data.

Which SQL statement is NOT correctly mapped to CRUD functionality?

• INSERT - Create

• SELECT - Read

• UPDATE - Update

• DELETE - Create

Answer explanation

The correct choice is DELETE - Create because DELETE operation is mapped to the Delete functionality in CRUD, not Create.

What does ACID stand for in database transactions?

• Atomicity, Connectivity, Isolation, Durability

• Accuracy, Consistency, Integrity, Durability

• Accuracy, Consistency, Isolation, Diversity

• Atomicity, Consistency, Isolation, Durability

Answer explanation

ACID stands for Atomicity, Consistency, Isolation, Durability in database transactions.

What does atomicity ensure in a database transaction?

• The transaction is the smallest unit and cannot be divided

• The transaction remains even if the system fails

• The database remains consistent before and after the transaction

• The transaction is isolated from other transactions

Answer explanation

Atomicity ensures that the transaction is the smallest unit and cannot be divided, maintaining its integrity.

What is an example of consistency in a database?

• A transaction is isolated from others

• Data is permanently stored after a transaction

• A transaction is completed fully or not at all

• Transferring funds from one account to another without loss

Answer explanation

The correct choice of transferring funds from one account to another without loss exemplifies consistency in a database by ensuring data integrity and accuracy during transactions.

How is isolation achieved in a database management system?

• By locking records affected by a transaction

• By completing all transactions at once

• By ensuring all transactions are atomic

• By writing data to permanent storage

Answer explanation

Isolation in a database management system is achieved by locking records affected by a transaction, ensuring that other transactions cannot access or modify them concurrently.

What does durability guarantee in a database transaction?

• Data integrity is maintained

• Transactions are processed in real-time

• Transactions can be divided into smaller parts

• Changes are not lost in case of a system failure

Answer explanation

Durability in a database transaction ensures that changes are not lost in case of a system failure, guaranteeing data persistence.

What is NOT a property required by every database transaction according to ACID?

• Atomicity

• Consistency

• Isolation

• Flexibility

Answer explanation

Flexibility is NOT a property required by every database transaction according to ACID. The correct choice is Flexibility.