Data Engineering Fundamentals 3

Question 1

What is a slowly changing dimension (SCD) Type 2 designed to do?

Accepted Answer

Preserve full history by adding new rows for changed attributes

Answer

Overwrite old values with new ones

Answer

Delete records that change frequently

Answer

Ignore all attribute changes

Question 2

Which guarantee does 'exactly-once' processing provide in a streaming system?

Accepted Answer

Each record is processed once with no duplicates or loss

Answer

Each record may be processed multiple times

Answer

Records can be lost during failures

Answer

Records are processed in random order

Question 3

What is the role of a message broker like Apache Kafka in a data architecture?

Accepted Answer

It decouples producers and consumers by buffering streams of events

Answer

It stores final analytical reports

Answer

It renders dashboards

Answer

It enforces relational constraints

Question 4

Which normalization concept aims to reduce data redundancy in a relational design?

Accepted Answer

Normalization to higher normal forms

Answer

Denormalization

Answer

Sharding

Answer

Indexing

Question 5

What does 'backfilling' a pipeline mean?

Accepted Answer

Processing past time periods that were missed or need reprocessing

Answer

Deleting historical partitions

Answer

Adding new columns to a table

Answer

Compressing old log files

Question 6

In CAP theorem, what must a distributed system trade off when a network partition occurs?

Accepted Answer

Consistency and availability

Answer

Cost and capacity

Answer

Latency and throughput

Answer

Security and durability

Question 7

What is the primary benefit of using a columnar storage engine for OLAP workloads?

Accepted Answer

Efficient reads and compression of specific columns for aggregations

Answer

Faster single-row inserts

Answer

Better support for transactions

Answer

Simpler row-level locking