DAC Big Data & Cloud Analytics 3 — Questions and Answers
Question 1: In HDFS, what is the default behavior for ensuring data durability across the cluster?
- Replicating each block across multiple nodes (Correct answer)
- Storing a single copy on the master node
- Compressing data into one file
- Encrypting blocks with unique keys
Correct answer: Replicating each block across multiple nodes
HDFS replicates each data block (default 3 copies) across DataNodes for fault tolerance.
Question 2: Which type of database is best suited for storing and querying highly connected data such as social networks?
- Graph database (Correct answer)
- Columnar warehouse
- Key-value cache
- Flat file store
Correct answer: Graph database
Graph databases model entities as nodes and relationships as edges, ideal for connected data.
Question 3: In stream processing, what does 'windowing' primarily allow you to do?
- Group events into finite time-based buckets for aggregation (Correct answer)
- Permanently store all events on disk
- Encrypt the data stream
- Convert streams into images
Correct answer: Group events into finite time-based buckets for aggregation
Windowing groups continuous stream events into bounded intervals so aggregations can be computed.
Question 4: Which Apache project is a distributed publish-subscribe messaging system commonly used for real-time data pipelines?
- Apache Kafka (Correct answer)
- Apache Ant
- Apache Maven
- Apache Tomcat
Correct answer: Apache Kafka
Apache Kafka is a distributed publish-subscribe streaming platform for real-time pipelines.
Question 5: In Azure, which service provides a managed Apache Spark and Delta Lake analytics platform?
- Azure Databricks (Correct answer)
- Azure DNS
- Azure Blob Static Website
- Azure Bastion
Correct answer: Azure Databricks
Azure Databricks is a managed analytics platform built around Apache Spark and Delta Lake.
Question 6: What does the CAP theorem state a distributed data store can guarantee at most two of?
- Consistency, Availability, Partition tolerance (Correct answer)
- Cost, Accuracy, Performance
- Concurrency, Atomicity, Persistence
- Caching, Auditing, Provisioning
Correct answer: Consistency, Availability, Partition tolerance
The CAP theorem says a distributed system can guarantee at most two of Consistency, Availability, and Partition tolerance.
Question 7: Which storage format is column-oriented and optimized for analytical queries in big data systems?
- Apache Parquet (Correct answer)
- CSV
- Plain text log
- XML
Correct answer: Apache Parquet
Apache Parquet is a columnar storage format that improves compression and analytical query speed.
DAC Big Data & Cloud Analytics 3
In HDFS, what is the default behavior for ensuring data durability across the cluster?