Redshift Spectrum lets a Redshift cluster query data sitting in S3 directly, without loading it into the warehouse first. It bridges your data warehouse and your data lake in a single query.
When to reach for it
Use Spectrum when you want to join warehouse tables with large, infrequently-accessed data in S3 without paying to load and store it all in Redshift. It uses the Glue Data Catalog for schema and, like Athena, benefits hugely from partitioned, columnar data. Scenario: “query S3 from Redshift without loading it” → Spectrum.
Test yourself
A team needs to run Redshift queries that join warehouse tables with terabytes of historical logs in S3, without loading the logs into the cluster. What enables this?
- Redshift Spectrum
- A Glue crawler only
- DynamoDB Streams
- S3 Transfer Acceleration
👉 Click to reveal the answer & explanation
Correct answer: A. Redshift Spectrum queries S3 data directly and joins it with warehouse tables, no loading required. A crawler (B) only catalogs schema; DynamoDB Streams (C) capture item changes; Transfer Acceleration (D) speeds uploads.
Related topics
Amazon Redshift · Amazon Athena · Glue Data Catalog
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