Analysts run infrequent, ad-hoc SQL queries directly against raw files in an S3 data lake — no regular reporting workload. What's the most cost-effective query layer?
A.A provisioned Redshift cluster
Provisioned Redshift bills 24/7 regardless of query frequency.
B.Amazon Athena over the Glue Data Catalog
Correct. Serverless, pay-per-scan — ideal for sporadic ad-hoc analysis.
C.Amazon EMR with Hive
An always-on EMR cluster costs more and requires ops.
D.Amazon RDS with a foreign data wrapper
RDS isn't designed to query raw lake files.
Why this answer
Athena is serverless — you pay only per TB scanned for occasional queries, with zero cluster to run. Redshift clusters bill continuously and make sense for sustained, performance-critical BI workloads.
Correct answer: B · Last reviewed 2026-10-26
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