- Company sizes or stages where RDS is disproportionate
- Very early-stage or hobby projects where the baseline costs associated with production-grade configurations (for example, Multi-AZ and backups) are not justified.
- Industries or use cases where alternative offerings are more suitable
- Organizations requiring the deepest-first SQL Server PaaS experience may prefer Azure SQL Database for tighter Microsoft-stack integration and platform-managed SQL Server features.
- Technical requirements RDS may not meet well
- Global active-active relational workloads with multi-region write requirements.
- Workloads requiring unsupported engine plugins, extensions, or OS-level tuning that are not permitted in a managed environment.
- Budget constraints
- Teams unable to sustain always-on instance costs or HA duplication should consider single-AZ configurations or alternative hosting models.
- Procurement and operational red flags
- If procurement or engineering teams cannot obtain clear answers on total run-rate including HA, backups, and data transfer, cost surprises are more likely after launch.
- Current limitations documented by the vendor
- Encryption / key-management operational risk
- Loss of access to a KMS key can render an encrypted DB instance inaccessible until key access is restored; key lifecycle and access management introduce operational risk that must be managed.
- IAM DB authentication engine limitations
- IAM database authentication is not available for Db2, Oracle, or SQL Server in RDS, and availability varies by engine.
- Features on the roadmap
- AWS communicates new features via release notes and "What’s New" posts; a centralized, exhaustive roadmap for every RDS sub-feature is not typically published.
- Scale limitations
- Scaling characteristics depend on engine, instance class, and storage configuration; load testing and architecture validation are recommended for large-scale deployments.
- Security or compliance gaps
- No unique, publicly documented compliance gap specific to RDS was identified in the reviewed materials; recurring issues typically stem from customer misconfiguration (for example, publicly exposed endpoints or overly permissive network rules).
- API limitations or integration constraints
- The managed service model imposes operational boundaries; certain administrative tasks must be performed via AWS-supported mechanisms.