Amazon RDS
- What it is
- Managed relational database service. AWS handles provisioning, OS and DB patching, backups, and failover.
- Engines: MySQL, PostgreSQL, MariaDB, Oracle, SQL Server, and Amazon Aurora (Db2 also supported).
- Shared responsibility shift
- AWS: hardware, OS, database engine patching, automated backups.
- You: schema design, indexing, query tuning, IAM/security-group configuration, and your data.
- You get no OS-level access — that is the trade for the managed experience.
- Availability and scaling
- Multi-AZ — a synchronous standby in another AZ. For high availability, automatic failover. Not for performance.
- Read replicas — asynchronous copies. For read scaling, and can span Regions. Not automatic failover.
- Storage autoscaling; vertical scaling by changing the instance class (brief downtime unless Multi-AZ).
- Not to be confused with
- Databases self-installed on Amazon EC2 — full OS control, full patching burden.
- Amazon DynamoDB — NoSQL key-value, not relational, no SQL joins.