Data Processing Data Processing MCQ 5 — Questions and Answers
Question 1: What is the key difference between OLTP and OLAP systems?
- OLTP handles large analytical queries; OLAP handles transactional writes
- OLTP is optimized for high-frequency, small transactional operations; OLAP is optimized for complex analytical queries over large datasets (Correct answer)
- OLTP stores unstructured data; OLAP stores structured data only
- OLTP uses columnar storage; OLAP uses row-based storage
Correct answer: OLTP is optimized for high-frequency, small transactional operations; OLAP is optimized for complex analytical queries over large datasets
OLTP systems are designed for fast, concurrent transactional reads/writes, while OLAP systems are optimized for aggregating and analyzing large historical datasets.
Question 2: Which data quality dimension measures how accurately data reflects the real-world entities it represents?
- Completeness
- Timeliness
- Accuracy (Correct answer)
- Consistency
Correct answer: Accuracy
Accuracy refers to how well data values correctly represent the actual real-world facts or entities they describe.
Question 3: What is a 'checksum' used for during data transfer and processing?
- Encrypting data before transmission
- Verifying data integrity by detecting errors or corruption (Correct answer)
- Compressing large files to reduce bandwidth usage
- Authorizing users to access specific datasets
Correct answer: Verifying data integrity by detecting errors or corruption
A checksum is a computed value derived from data that is used to detect accidental changes or corruption during storage or transmission.
Question 4: In distributed data processing, what does 'fault tolerance' ensure?
- That all nodes process data at the exact same speed
- That the system continues to operate correctly even when one or more components fail (Correct answer)
- That data is encrypted using fault-resistant algorithms
- That queries are executed without using indexes
Correct answer: That the system continues to operate correctly even when one or more components fail
Fault tolerance allows a distributed system to continue functioning and complete processing tasks even if some nodes fail.
Question 5: What is 'change data capture' (CDC) primarily used for?
- Detecting unauthorized access to databases
- Tracking and capturing changes made to database records for replication or auditing (Correct answer)
- Automatically updating data schemas when new fields are added
- Compressing transaction logs to save disk space
Correct answer: Tracking and capturing changes made to database records for replication or auditing
CDC identifies and captures row-level changes (inserts, updates, deletes) in a database so they can be replicated or processed downstream.
Question 6: Which of the following is an example of unstructured data?
- A relational database table with customer orders
- A CSV file with product prices
- A collection of customer support chat transcripts (Correct answer)
- A JSON file with API response fields
Correct answer: A collection of customer support chat transcripts
Unstructured data lacks a predefined schema or format; free-form text like chat transcripts is a classic example.
Question 7: What does 'exactly-once semantics' guarantee in a data streaming system?
- Each message is delivered at least once but possibly more
- Each message is processed exactly one time, with no duplicates and no data loss (Correct answer)
- Messages are processed in strict chronological order
- Each consumer receives a unique copy of every message
Correct answer: Each message is processed exactly one time, with no duplicates and no data loss
Exactly-once semantics ensure every record is processed precisely one time, preventing both data loss and duplicate processing.
Data Processing Data Processing MCQ 5
What is the key difference between OLTP and OLAP systems?