Database
Managed databases, grouped by data model. Pick by the shape of the data and the access pattern, not by brand.
| Service | Model | Choose when | Key distinction |
|---|---|---|---|
| Amazon RDS | Relational (6 engines) | Standard SQL workload you want managed | AWS patches OS + engine; you own schema/queries |
| Amazon Aurora | Relational, cloud-native | MySQL/PostgreSQL at higher performance | Distributed storage, 15 replicas, Serverless option |
| Amazon DynamoDB | NoSQL key-value/document | Serverless, millisecond scale, flexible schema | No servers, no joins, single-digit ms at any scale |
| Amazon MemoryDB for Redis | In-memory, durable | Microsecond speed as the system of record | Durable (multi-AZ log) — unlike a cache |
| Amazon Neptune | Graph | Highly connected data, recommendations, fraud | Relationships are first-class |
- Relational vs NoSQL: joins and fixed schema (RDS/Aurora) vs flexible schema and horizontal scale (DynamoDB).
- MemoryDB vs ElastiCache: MemoryDB is a durable primary DB; ElastiCache is a disposable cache in front of another DB.