MCQ Collection
Big Data Analytics MCQs
Practice Big Data Analytics questions with answers and explanations.
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Correct Answer: C. Large sequential reads and writes
Explanation:
HDFS targets high-throughput streaming access to large files.
It is not designed as a general-purpose low-latency file system.
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Correct Answer: C. Its design favors large immutable or append-oriented files rather than in-place mutation
Explanation:
HDFS prioritizes throughput and fault-tolerant block storage.
Systems such as HBase are better suited to random record access.
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Correct Answer: C. To define how final key-value pairs are written
Explanation:
OutputFormat controls destination structure and serialization.
It also creates the RecordWriter used by tasks.
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Correct Answer: C. A distributed metric aggregated across task attempts
Explanation:
Counters track events such as malformed records or processed rows.
They are useful for monitoring and data-quality checks.
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Correct Answer: C. Emitting only records that satisfy a condition
Explanation:
Filters are often implemented as map-only jobs.
Records that fail the predicate produce no output.
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Correct Answer: D. Availability
Explanation:
Availability requires the system to respond even when some nodes are unavailable.
The response may not contain the most recent data in some designs.
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Correct Answer: D. Files are generally appended or read rather than modified at arbitrary positions
Explanation:
Avoiding random in-place updates simplifies replication and consistency.
HDFS supports appends in many deployments but not arbitrary block edits.
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Correct Answer: D. The scheduler can exploit data locality when assigning tasks
Explanation:
Tasks can run on or near nodes holding the required blocks.
This reduces expensive network transfer.
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Correct Answer: D. Only successful task output becomes visible as final job output
Explanation:
Task attempts may fail or be speculated.
Commit protocols prevent partial or duplicate files from appearing as final results.
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Correct Answer: D. Too many distinct counters create coordination and memory overhead
Explanation:
Counters are aggregated through the framework and are not intended as arbitrary per-key storage.
A small, meaningful set is most effective.
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Correct Answer: D. A mapping from terms to the documents or records containing them
Explanation:
Mappers emit terms with document identifiers.
Reducers aggregate the document lists for each term.
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Correct Answer: A. The system continues operating despite lost or delayed network messages between nodes
Explanation:
Distributed networks can experience communication failures.
Partition-tolerant systems continue functioning while groups of nodes cannot communicate.
