Database Fundamentals Chapter 5 - Set 2

What does Database Transaction Management ensure?

• High availability of data

• ACID properties are maintained

• Data replication across servers

• Fast query processing

Answer explanation

Database Transaction Management ensures that ACID properties (Atomicity, Consistency, Isolation, Durability) are maintained, which are crucial for reliable transactions in a database system.

Which of the following is NOT a property of ACID?

• Atomicity

• Isolation

• Durability

• Accessibility

Answer explanation

Accessibility is not a property of ACID. ACID stands for Atomicity, Consistency, Isolation, and Durability, which are essential for ensuring reliable transactions in databases.

What is the main characteristic of a Batch Transaction Processing System?

• Transactions are processed in real time

• Transactions are processed in batches at intervals

• Transactions are processed individually

• Transactions are processed only when errors occur

Answer explanation

The main characteristic of a Batch Transaction Processing System is that transactions are processed in batches at intervals, rather than in real time or individually. This allows for efficient handling of large volumes of transactions.

What type of transaction system handles transactions in real-time as they occur?

• Batch Processing

• OLTP

• Real-time processing

• Deferred transaction processing

Answer explanation

OLTP (Online Transaction Processing) systems handle transactions in real-time as they occur, allowing for immediate processing and response. This distinguishes it from batch processing and deferred transaction processing.

Which transaction system prioritizes very low response times?

• Batch Processing

• OLTP

• Real-time Transaction Processing

• Transaction Recovery

Answer explanation

Real-time Transaction Processing is designed for scenarios requiring immediate response, prioritizing very low response times, unlike Batch Processing or OLTP, which may not focus on instant processing.

What does Atomicity in a transaction ensure?

• All operations succeed or none of them do

• Data is accessible by multiple users

• Transaction data is saved after a system crash

• Transactions are isolated from each other

Answer explanation

Atomicity ensures that in a transaction, all operations must succeed or none of them do. This guarantees that the database remains consistent, as partial updates are not allowed.

What is the purpose of the COMMIT statement in SQL?

• Begin a new transaction

• Cancel a transaction

• Confirm and save transaction changes

• Lock a table

Answer explanation

The COMMIT statement in SQL is used to confirm and save all changes made during the current transaction. This ensures that all modifications are permanently applied to the database.

What problem arises when multiple transactions overwrite each other's updates?

• Inconsistent retrieval

• Lost update

• Uncommitted data

• Deadlock

Answer explanation

The 'lost update' problem occurs when multiple transactions overwrite each other's changes, leading to the loss of updates made by one transaction. This results in inconsistent data, as the final state does not reflect all updates.

Which of the following uses locks to control concurrent transaction access?

• Deadlock resolution

• Concurrency control with locking methods

• Batch processing system

• Commit statement

Answer explanation

Concurrency control with locking methods is specifically designed to manage access to database resources by using locks, ensuring that transactions do not interfere with each other, which is essential for maintaining data integrity.

What type of lock allows multiple transactions to read data but prevents writing?

• Exclusive lock

• Shared lock

• Intent lock

• Page-level lock

Answer explanation

A shared lock allows multiple transactions to read data simultaneously while preventing any write operations. This ensures data consistency during read operations, making it the correct choice for the question.