Data Processing Computer-Based Test On Data-Processing 5

Question 1

Which of the following is a characteristic of columnar storage compared to row-based storage?

Accepted Answer

Better performance for analytical queries that aggregate a few columns across many rows

Answer

Columnar storage groups values of the same column together, so analytical queries that read only a few columns can skip irrelevant data.

Question 2

In data processing, 'idempotency' means that an operation:

Accepted Answer

Produces the same result whether applied once or multiple times

Answer

An idempotent operation yields the same outcome regardless of how many times it is applied, which is critical for safe retries in distributed systems.

Question 3

Which processing model does Apache Kafka primarily support?

Accepted Answer

Real-time event streaming and message queuing

Answer

Apache Kafka is a distributed event-streaming platform designed for high-throughput, low-latency publishing and subscribing to real-time data streams.

Question 4

A 'surrogate key' in a data warehouse is best described as:

Accepted Answer

A system-generated artificial key used to uniquely identify dimension records

Answer

Surrogate keys are integer identifiers assigned by the warehouse system, independent of source system keys, to handle slowly changing dimensions and key conflicts.

Question 5

In data compression, which technique identifies repeated patterns and replaces them with shorter codes?

Accepted Answer

Run-length encoding

Answer

Run-length encoding (RLE) compresses data by replacing consecutive repeated values with a single value and a count.

Data Processing Practice Test

Data Processing Practice Test

Data Processing Computer-Based Test On Data-Processing 5