Database And Storage Migration Strategy — AWS Solutions Architect (SAA-C03)
Migration tool selection turns on downtime tolerance
The scenario describes moving a relational database to RDS with minimal downtime. Candidates select AWS Backup or manual snapshot restore because those are familiar RDS operations. The exam is testing AWS DMS, which provides continuous replication during migration to minimize cutover downtime. Snapshot restores require a full cutover window. SCT converts schema when source and target engines differ. The correct migration path depends on source engine, target engine, acceptable downtime, and whether schema transformation is required before replication begins.
What This Pattern Tests
The exam describes a data migration and tests tool selection. DMS handles database migration with continuous replication for zero-downtime cutover. DataSync handles file/object migration from on-premises NAS/NFS to S3, EFS, or FSx at up to 10 Gbps. Snow Family (Snowcone 8TB, Snowball Edge 80TB, Snowmobile 100PB) handles offline transfer when network bandwidth is insufficient. Transfer Family provides managed SFTP/FTP endpoints for S3. The trap is using DMS for file migration (it handles databases, not files) or online transfer for 100TB over a 100 Mbps link (would take 92 days — Snowball takes a week with shipping).
Decision Axis
Data type (database vs. files), volume (GB vs. PB), and network bandwidth determine migration tool and online vs. offline method.
Associated Traps
More Top Traps on This Exam
Decision Rules
When custom iterative Spark logic, strict SLA completion windows, and team-owned Spark expertise are all present, choose EMR over Glue because per-executor tuning and instance fleet selection directly map to the time constraint in a way that Glue's DPU model cannot guarantee.
When data volume is large, transformation logic is custom and iterative, and a hard SLA window is specified, prefer a cluster platform that exposes per-executor Spark configuration over a serverless ETL service that abstracts resource allocation.
Domain Coverage
Difficulty Breakdown