Data Warehousing on AWS Training Data Warehousing on AWS: Architecture Design 2 — Questions and Answers
Question 1: Which Amazon Redshift feature allows you to query data directly in S3 without loading it into Redshift tables?
- Redshift Spectrum (Correct answer)
- Redshift Concurrency Scaling
- Redshift Federated Query
- Redshift Data Sharing
Correct answer: Redshift Spectrum
Redshift Spectrum extends Redshift queries to data stored in S3 without requiring data to be loaded into the cluster.
Question 2: In a Redshift architecture, what is the purpose of a leader node?
- It stores actual columnar data blocks
- It coordinates query execution and communicates with clients (Correct answer)
- It performs parallel scan operations on slices
- It manages backup snapshots to S3
Correct answer: It coordinates query execution and communicates with clients
The leader node receives client queries, develops execution plans, and coordinates parallel processing across compute nodes.
Question 3: A company needs its data warehouse to handle unpredictable query spikes without degrading performance for other users. Which Redshift feature addresses this?
- Elastic Resize
- Concurrency Scaling (Correct answer)
- Workload Management (WLM)
- Redshift Serverless
Correct answer: Concurrency Scaling
Concurrency Scaling automatically adds transient cluster capacity to handle bursts of concurrent queries.
Question 4: What distribution style should you choose for a large fact table in Redshift to minimize data movement during joins?
- ALL distribution
- EVEN distribution
- KEY distribution (Correct answer)
- AUTO distribution
Correct answer: KEY distribution
KEY distribution collocates rows with the same distribution key value on the same node slice, reducing data movement during joins.
Question 5: Which AWS service acts as the primary staging area for data before it is loaded into Amazon Redshift using the COPY command?
- Amazon EBS
- Amazon RDS
- Amazon S3 (Correct answer)
- Amazon DynamoDB
Correct answer: Amazon S3
The Redshift COPY command loads data in parallel from Amazon S3, making S3 the standard staging layer for bulk loads.
Question 6: In a data warehouse hub-and-spoke architecture on AWS, what role does the central hub typically serve?
- A transactional OLTP database for real-time writes
- An integrated enterprise data warehouse storing conformed data (Correct answer)
- A purpose-built analytics sandbox for ad hoc queries
- A hot cache layer for frequently accessed dashboard data
Correct answer: An integrated enterprise data warehouse storing conformed data
The hub in a hub-and-spoke model is the central EDW that stores conformed, integrated data, with data marts as spokes.
Question 7: Which compression encoding in Amazon Redshift is automatically chosen when no encoding is specified and is best for columns with many repeated values?
- BYTEDICT (Correct answer)
- ZSTD
- RAW
- LZO
Correct answer: BYTEDICT
BYTEDICT (dictionary encoding) is highly effective for low-cardinality columns with many repeated values and is often chosen automatically.
Data Warehousing on AWS Training Data Warehousing on AWS: Architecture Design 2
Which Amazon Redshift feature allows you to query data directly in S3 without loading it into Redshift tables?