Database And Storage Migration Strategy — AWS Solutions Architect Pro (SAP-C02)
DMS with CDC vs One-Time Load: Cutover Tolerance Decides
DMS with change data capture keeps source and target synchronized during the migration window. When cutover happens, only the delta since the last sync applies, making the downtime window minutes long. DMS without CDC performs a one-time full load that requires the source to be quiesced during import, making the window proportional to data volume. Heterogeneous migrations, such as Oracle to Aurora PostgreSQL, require the Schema Conversion Tool to transform the schema and stored procedures before DMS handles data movement. The cutover tolerance stated in the scenario decides which mode is correct: near-zero downtime requires CDC; an acceptable maintenance window permits a full-load migration.
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
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Decision Rules
When source and target database engines differ (heterogeneous migration), AWS SCT must precede AWS DMS to convert schema objects and stored procedures; DMS alone satisfies the minimal-downtime constraint via CDC but fails the engine-compatibility constraint, making SCT the deciding differentiator between the correct answer and the near-right distractor.
Heterogeneous engine migration (Oracle → Aurora PostgreSQL) requires SCT to automate schema and stored-procedure conversion before DMS performs ongoing replication; omitting SCT and substituting manual or custom conversion scripts satisfies the data-movement requirement but creates unquantified operational complexity that expands the effective cutover window beyond the stated constraint and violates an explicit compliance directive.
Domain Coverage
Difficulty Breakdown