Data Processing Computer-Based Test On Data-Processing 4 — Questions and Answers
Question 1: In MapReduce, the 'shuffle and sort' phase occurs between:
- Input and Map
- Map and Reduce (Correct answer)
- Reduce and Output
- Split and Input
Correct answer: Map and Reduce
After the Map phase, the shuffle and sort phase groups and sorts intermediate key-value pairs before they are sent to Reducers.
Question 2: Which data format is most commonly used for exchanging data between web services today?
- CSV
- JSON (Correct answer)
- COBOL copybooks
- Fixed-width text
Correct answer: JSON
JSON (JavaScript Object Notation) is the dominant format for REST APIs and web service data exchange due to its human-readable, lightweight structure.
Question 3: What is a 'data warehouse' primarily optimized for?
- High-frequency transactional writes
- Long-term analytical queries over large historical datasets (Correct answer)
- Real-time event streaming
- Storing unstructured multimedia files
Correct answer: Long-term analytical queries over large historical datasets
Data warehouses use columnar storage and denormalized schemas to support complex analytical queries across large volumes of historical data.
Question 4: Which technique is used to split a large database table across multiple servers to improve scalability?
- Replication
- Normalization
- Sharding (Correct answer)
- Indexing
Correct answer: Sharding
Sharding horizontally partitions a table so each shard holds a subset of rows, distributing load across multiple nodes.
Question 5: In a computer-based data processing test, a 'data dictionary' serves as:
- A glossary of business terms for end users
- A centralized repository of metadata describing data elements, types, and relationships (Correct answer)
- A log of all queries executed against a database
- A backup of the most recent dataset snapshot
Correct answer: A centralized repository of metadata describing data elements, types, and relationships
A data dictionary documents the structure, meaning, and constraints of each data element within a system.
Question 6: Which of the following best describes 'data profiling'?
- Encrypting data before archiving it
- Analyzing data to understand its structure, content, and quality (Correct answer)
- Compressing data to reduce storage costs
- Replicating data to a secondary site for disaster recovery
Correct answer: Analyzing data to understand its structure, content, and quality
Data profiling examines datasets to discover statistics, patterns, anomalies, and quality issues before processing or integration.
Question 7: When processing data with a 'pipeline' architecture, each stage:
- Receives the full raw dataset and processes it independently
- Processes output from the previous stage and passes results to the next (Correct answer)
- Runs in isolation with no dependency on other stages
- Must complete before the next stage begins receiving any data
Correct answer: Processes output from the previous stage and passes results to the next
In a pipeline, each stage consumes the output of the preceding stage, enabling data to flow through sequential transformations.
Data Processing Computer-Based Test On Data-Processing 4
In MapReduce, the 'shuffle and sort' phase occurs between: