What is the difference between Autonomous Data Warehouse (ADW) and Autonomous Transaction Processing (ATP) databases?

ADW and ATP are tailored for different workloads:

Correct Answer (C): “Only ADW uses columnar compression by default” is true. ADW employs Hybrid Columnar Compression (HCC) for analytics, optimizing storage and query performance, while ATP uses row-based storage for transactional workloads (though HCC can be enabled manually).

Incorrect Options:

A: Both ADW and ATP manage optimizer statistics automatically.

B: Autoscaling is supported by both ADW and ATP.