SDS DASCA Senior Data Scientist Free Practice Exam Questions (2025 Updated)

Apache SpamAssassin is one of the most widely used open-source tools for spam email detection.

It applies a rule-based system combined with Bayesian filtering, heuristics, and collaborative filtering methods to classify incoming emails as spam or legitimate.

Option A (Spam emails): Correct, this is the main function.

Option B (Big attachments): Incorrect. Large attachment filtering is not its primary purpose.

Option C (Email with virus): Incorrect. That falls under antivirus or malware detection tools, not SpamAssassin.

Option D: Incorrect since A is valid.

Thus, the correct answer is Option A (Spam emails).

The DevOps movement evolved as a natural extension of the Agile methodology.

Agile (Option A): Agile emphasizes iterative development, collaboration, and flexibility. While Agile improved software development speed, it created challenges in integrating development with IT operations. DevOps emerged to address this by bringing operations into the Agile cycle — enabling continuous integration, delivery, and deployment.

Waterfall (Option B): Incorrect. Waterfall is a rigid, sequential methodology, fundamentally opposite to the DevOps philosophy.

Promise-based algorithms (Option C): Not a methodology — irrelevant here.

Test-driven development and model-driven development (Option D): While these practices support DevOps, they are not the origin of the movement.

Thus, the DevOps movement is an outgrowth of Agile methodology.

The Hadoop ecosystem consists of multiple components, but the two core components that define Hadoop are:

HDFS (Hadoop Distributed File System): Provides fault-tolerant, scalable storage across distributed clusters. It is the backbone for storing massive datasets in a distributed fashion.

MapReduce Framework: Provides the parallel computing and data processing layer in Hadoop, enabling batch analysis over distributed datasets.

Option A: Correct, HDFS is essential.

Option B: Correct, MapReduce is essential.

Option C: Incorrect, Spark is a newer processing framework, but it is not originally part of Hadoop core.

Option D: Correct answer since both HDFS and MapReduce are considered the fundamental parts of Hadoop.

Option E: Incorrect, because Spark is not a core Hadoop component (though it integrates with Hadoop).

Service Level Agreements (SLAs) define performance commitments between service providers (like ISPs) and customers. Key SLA metrics include:

MTBF (Option A): Measures reliability by defining the expected average time between service failures.

MTTR (Option B): Measures availability by defining how quickly service can be restored after a failure.

TAT (Option C): Measures responsiveness in resolving customer requests or incidents.

All three are standard SLA performance specifications. Hence, the correct answer is Option D (All of the above).