CDP (Big Data Science) 2

Question 1

Which CAP theorem property is sacrificed by Apache Cassandra by default in favor of availability and partition tolerance?

Accepted Answer

Consistency

Answer

Cassandra is an AP system that prioritizes availability and partition tolerance, offering only eventual consistency by default.

Question 2

In a Lambda architecture, what is the primary role of the speed layer?

Accepted Answer

Provide low-latency views of recent data not yet processed by the batch layer

Answer

The speed layer processes recent data in real-time to compensate for the high latency of the batch layer.

Question 3

What does the 'embarrassingly parallel' term mean in the context of big data processing?

Accepted Answer

Tasks can be divided into independent subtasks with no dependency between them

Answer

Embarrassingly parallel problems can be split into completely independent subtasks, requiring no communication between parallel workers.

Question 4

Which technique is used in Spark to avoid full data shuffles when joining a large dataset with a small one?

Accepted Answer

Broadcast join

Answer

A broadcast join sends the smaller dataset to all worker nodes, eliminating the costly shuffle of the large dataset.

Question 5

In the context of streaming analytics, what is 'watermarking' used for?

Accepted Answer

Handling late-arriving data by defining a threshold for event-time delays

Answer

Watermarking sets a maximum tolerated delay for late data, allowing the system to finalize window computations despite out-of-order events.

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