Quick Note — Recommend a Data Storage Solution to Balance Features, Performance, and Costs
AZ-305 › Unit 2 › Design data storage for semi-structured and unstructured data › Recommend a data storage solution to balance features, performance, and costs
Quick Note — Recommend a Data Storage Solution to Balance Features, Performance, and Costs
Choosing the right Azure data store is rarely about which service is "best" — it is about which trade-offs you can accept. Every storage decision lands somewhere on a triangle of features, performance, and cost, and every service in Azure's data portfolio occupies a different corner. This lesson teaches you to map a workload's characteristics to the storage service whose trade-offs most closely fit, then defend the choice against close-but-wrong siblings on the AZ-305 exam.
Retrieval target
- Recommend a Data Storage Solution to Balance Features, Performance, and Costs
- Closed-book recall
- 5 minutes
- Open the full lesson after a miss
Decision anchors
| Prompt | Compact answer |
|---|---|
Reserved Capacity (Storage / Cosmos / SQL) | A pre-purchase of 1 or 3 years of capacity at a discount of up to ~60% vs pay-as-you-go. Available for Storage (Blob), Cosmos DB (RU/s), SQL Database (vCore), SQL MI (vCore). Scoped to a subscription or shared. Commitment is refundable — but cancelled commitments across a billing scope can't exceed USD in a 12-month rolling window, and Microsoft isn't currently charging an early-termination fee. The scope is reassignable at any time. Reservations purchased after February 1, 2027 aren't eligible for exchange where the service is covered by a savings plan. Pair with Azure Hybrid Benefit for compounding savings on SQL workloads. |
Lifecycle Management (Blob) — what it can move | A policy that runs daily on a Storage account, moving / deleting blobs by age, last-access time, or blob index tag. Transitions: Hot → Cool → Cold → Archive and outright delete. Rules can target a path prefix or a tag filter (e.g., Class=Cold). Output is per-blob actions — no compute cost. The standard cost-control lever for unstructured stores. |
Premium performance tier (Storage / SQL / Cosmos) | Storage Premium — SSD-backed, low-latency, narrower redundancy (LRS / ZRS), used for performance-sensitive Blob, File, or VM disks. Higher $/GB, but transactions per second far higher than Standard. SQL Premium / Business Critical — local SSD + Always-On replicas. Cosmos Autoscale/Provisioned — guaranteed RU/s.… |
Cost calculators — Azure Pricing Calculator vs Azure Migrate business case | Pricing Calculator — interactive estimator for an Azure-only future-state cost: assemble services, regions, tiers, instance counts → output is a /year figure. Use during design. Azure Migrate business case (the standalone TCO Calculator is retired) — compare on-prem cost vs Azure cost from appliance-discovered or CSV-imported inventory; outputs on-premises-vs-Azure TCO, year-over-year cash flow, and ROI. Use to justify a migration to leadership. |
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.