Which AWS service is a fully managed, petabyte-scale data warehouse service?

Amazon Redshift is the fully managed, petabyte-scale data warehouse service in AWS. It is designed specifically for large-scale data analytics and enables you to run complex queries against vast amounts of structured and semi-structured data. Redshift employs columnar storage, which allows for highly optimized querying and performance, making it suited for data warehousing purposes.

This service simplifies the management of data warehouses by automating tasks such as backups, scaling, and patching, allowing users to focus on querying and analyzing their data rather than on the underlying infrastructure. Its ability to scale horizontally supports workloads that can involve terabytes to petabytes of data, catering to organizations that need robust analytics capabilities.

In comparison to the other services listed, Amazon RDS is a managed relational database service but not specifically a data warehouse. Amazon S3 is an object storage service that can store and retrieve any amount of data but does not provide data warehousing capabilities or optimized query performance designed for analytics. Amazon DynamoDB is a managed NoSQL database service best suited for applications that require low latency and high throughput but is not used for data warehousing either. Therefore, Amazon Redshift stands out as the correct choice for a fully managed data warehouse service in AWS.