Data Processing Data Processing MCQ 3 — Questions and Answers
Question 1: Which indexing strategy is most effective when queries frequently filter on multiple columns together?
- Single-column index
- Composite index (Correct answer)
- Full-text index
- Clustered index on the primary key only
Correct answer: Composite index
A composite (multi-column) index covers multiple columns in a single index structure, speeding up queries that filter on those columns together.
Question 2: What does 'data lineage' track in a data processing system?
- The physical location of data storage devices
- The origin, movement, and transformation history of data (Correct answer)
- The number of users who accessed a dataset
- The encryption keys used for data protection
Correct answer: The origin, movement, and transformation history of data
Data lineage records the complete journey of data — where it came from, how it was transformed, and where it moved.
Question 3: A company processes 500 GB of log files every night. Which processing model is most appropriate?
- Real-time stream processing
- Batch processing (Correct answer)
- In-memory processing only
- Manual data entry
Correct answer: Batch processing
Batch processing is ideal for large volumes of data accumulated over a period and processed at scheduled intervals, such as nightly log analysis.
Question 4: What is the role of a 'message broker' like Apache Kafka in data processing architectures?
- It stores processed results permanently in a relational database
- It acts as an intermediary that decouples data producers and consumers, managing data streams (Correct answer)
- It compresses data files before archiving
- It validates SQL queries before execution
Correct answer: It acts as an intermediary that decouples data producers and consumers, managing data streams
A message broker like Kafka decouples producers from consumers, buffering and routing data streams reliably between systems.
Question 5: Which format is most commonly used for data exchange in modern REST APIs due to its human-readable structure?
- CSV
- JSON (Correct answer)
- Avro
- Parquet
Correct answer: JSON
JSON (JavaScript Object Notation) is the dominant format for REST API data exchange because it is human-readable and natively supported in web environments.
Question 6: What problem does 'schema evolution' address in long-running data pipelines?
- Scaling storage capacity as data volumes grow
- Managing changes to data structure over time without breaking existing consumers (Correct answer)
- Optimizing query execution plans automatically
- Replicating data across geographic regions
Correct answer: Managing changes to data structure over time without breaking existing consumers
Schema evolution handles changes to data schemas (adding/removing fields) over time while maintaining backward or forward compatibility.
Question 7: In MapReduce, the 'shuffle and sort' phase occurs between which two steps?
- Before Map and after Reduce
- Between Map and Reduce (Correct answer)
- After Reduce and before output
- Before both Map and Reduce
Correct answer: Between Map and Reduce
In MapReduce, shuffle and sort groups and organizes the output of Map tasks by key before sending them to the appropriate Reduce tasks.
Data Processing Data Processing MCQ 3
Which indexing strategy is most effective when queries frequently filter on multiple columns together?