Quick Note — Recommend a Solution for Migrating Databases
AZ-305 › Unit 4: Design infrastructure solutions › Design migrations › Recommend a solution for migrating databases
Quick Note — Recommend a Solution for Migrating Databases
A large international bank prepares its 200-database SQL Server estate for full migration to Azure. The team picks "BACPAC export / import" because it's the option they remember from a tutorial. The first database — a 4 TB transactional system — takes 58 hours to export. By the time it imports, the source has moved ahead by two business days; reconciling the gap takes a week. The architect intervenes: switch to Azure Database Migration Service (DMS) in online mode, which continuously replicates changes from source to target. Cutover for the next database takes minutes of read-only window instead of 58 hours.…
Retrieval target
- Recommend a Solution for Migrating Databases
- Closed-book recall
- 5 minutes
- Open the full lesson after a miss
Decision anchors
| Prompt | Compact answer |
|---|---|
Azure Database Migration Service (Azure DMS) | Microsoft's managed database migration service. Migrates SQL Server, Oracle, MySQL, PostgreSQL, MongoDB to Azure SQL DB / MI / VM / Flexible Server / Cosmos DB. Two modes: offline (single-shot, downtime allowed) and online (continuous replication then cutover, near-zero downtime). Replaces hand-rolled BACPAC / restore scripts. |
Data Migration Assistant (DMA) | A downloadable Windows tool for SQL Server migration assessment. Inspects the source DB and flags: compatibility issues (deprecated features, T-SQL not supported in target), partially supported features, target recommendation (SQL DB vs MI vs VM). Also generates an Excel report you can share with stakeholders. Run before triggering DMS to know which target tier fits and what code needs changing. |
| DMS offline vs online migration | Offline — single backup-restore-style cutover. Source DB is taken offline at cut start, full restore on target, app pointed at target. Downtime = entire copy time ( minutes-hours-days by DB size). Simpler, cheaper, fine when downtime budget is generous. Online — DMS keeps the target in sync via log shipping / CDC; cutover is the final delta sync + DNS switch. Downtime in minutes.… |
| BACPAC export/import migration | Hand-rolled migration path that doesn't use DMS: export source SQL DB to a .bacpac file (schema + data) in Blob, then import it into the target Azure SQL DB. One-shot, downtime equal to copy time, no log shipping. Cheap and simple for small DBs ( GB). For larger DBs, DMS offline / online is faster and supports more source engines. |
Read the answers once, then cover the right-hand column and reconstruct each one from the prompt. A useful answer names the requirement, the recommended control or service boundary, and the nearest alternative it rejects. If you can only recognize the answer after seeing it, retrieval is not yet secure.
Ninety-second explanation
Without notes, explain:
- What requirement signals this learning objective rather than a neighbouring one?
- Which two solution families are most likely to be compared?
- Which hard constraint eliminates the strongest distractor?
- What identity, network, data, or failure boundary must appear in the design?
- Which operational test would prove the recommendation works?
Then compare your explanation with the full lesson. Record the missing decision rule—not merely the missed product name—in your error log.
When to open the full lesson
Open the curriculum-linked lesson when you cannot explain a comparison, when a scenario depends on a numeric limit or SKU feature, or when the service is on a retirement path. Use current Microsoft Learn documentation for availability, limits, pricing, naming, and migration milestones; the quick note is intentionally compact.
Source and freshness
Derived from the linked AZ-305 lesson and retrieval deck, grounded in both attached course sources. Reviewed 2026-08-02. Current Microsoft documentation controls changing product contracts.