Data Warehousing on AWS Training Data Warehousing on AWS: Workload Management 3

Question 1

Which Redshift WLM feature automatically moves short-running queries out of a long-running queue to reduce wait times?

Accepted Answer

Short-query acceleration (SQA)

Answer

Short-query acceleration (SQA) uses machine learning to identify short-running queries and execute them in a dedicated fast lane, bypassing the main WLM queues.

Question 2

When configuring user group routing rules in Redshift WLM, what happens if a user belongs to two groups that map to different queues?

Accepted Answer

The query is routed to the first matching queue in the WLM configuration order

Answer

Redshift WLM evaluates queue routing rules in order and routes the query to the first queue whose user group or query group criteria match.

Question 3

What is the purpose of the 'concurrency scaling' feature in Redshift in relation to WLM?

Accepted Answer

It automatically adds transient cluster capacity when queued queries exceed thresholds

Answer

Concurrency scaling adds temporary cluster capacity to handle bursts of queued queries, seamlessly routing overflow workloads to transient clusters.

Question 4

In Redshift WLM, which memory allocation strategy helps prevent a single large query from consuming all cluster memory?

Accepted Answer

Setting per-queue memory percentages so no single queue can exceed its allocation

Answer

By assigning specific memory percentages to each WLM queue, you ensure no single queue (or the queries within it) can consume more than its allocated share of cluster memory.

Question 5

Which action does a query 'hop' perform in the context of Redshift WLM query hopping?

Accepted Answer

A timed-out query is cancelled and resubmitted to a queue with a longer timeout

Answer

Query hopping occurs when a query exceeds its WLM queue timeout; it is cancelled and automatically restarted in a queue configured with a higher (or no) timeout limit.

Data Warehousing on AWS Training Practice Test

Data Warehousing on AWS Training Practice Test

Data Warehousing on AWS Training Data Warehousing on AWS: Workload Management 3