In one sentence
Athena fits ad hoc queries directly over S3; Redshift fits sustained, frequent, and complex warehouse analytics.
Key points
- Athena is serverless, billed by scanned data, and leaves data in S3.
- Redshift is a cloud data warehouse for stable BI, complex joins, and enterprise analytics.
- A lake and warehouse often coexist: S3 holds raw data, Redshift holds analytical models.
Exam focus
- Occasional query, low operations, direct S3 access → Athena.
- Frequent complex BI and a stable warehouse → Redshift.
Common pitfalls
- Do not choose by product name alone; confirm data type, latency, control, operations, and cost constraints.
Remember
Athena queries S3; Redshift is the warehouse.