AZ-305 Design data storage solutions Practice Question
Your company has a large number of unstructured files (images, videos) that need to be stored cost-effectively in Azure. The data is accessed infrequently but must be available within minutes when needed. Which storage tier should you recommend?
⚠ Common exam trap
Candidates often confuse the Archive tier's low storage cost with immediate availability, overlooking the mandatory rehydration latency that violates the 'within minutes' requirement.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Cool tier.
The Cool tier is designed for data that is infrequently accessed but requires immediate availability when needed. It offers lower storage costs than the Hot tier while maintaining low-latency access (within minutes), making it ideal for unstructured files like images and videos that are accessed rarely but must be retrievable on demand.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Premium tier.
Why it's wrong here
Azure Premium Block Blob Storage is designed for high-throughput, low-latency workloads that require single-digit millisecond response times, using SSD-backed accounts that substantially increase per-GB storage cost. For a large set of unstructured images that are accessed infrequently, this tier is over-provisioned and not cost-effective. Its pricing model is based on high IOPS and performance, not on storage efficiency for occasional reads, so it does not meet the business requirement of minimizing cost while allowing retrieval within minutes.
- ✗
Archive tier.
Why it's wrong here
The Archive tier stores blobs in an offline state, meaning data cannot be read directly and must first be rehydrated to Hot or Cool before access. Rehydration time with standard priority can take up to 15 hours, and even high-priority rehydration typically takes about one hour—so retrieval is far from 'within minutes.' Additionally, Archive imposes a 180-day minimum storage duration, and early deletion incurs penalty charges, making it unsuitable for any workflow that needs timely access.
- ✓
Cool tier.
Why this is correct
The Cool tier is an online access tier intended for data that is infrequently accessed (a few times a month) but must be available immediately on demand. It offers lower storage costs and lower write/read transaction costs than Hot, allowing you to store many images economically while still supporting low-latency reads that can complete within milliseconds. Because there is no rehydration step, images are directly readable, and the 30-day minimum retention period aligns with typical lifecycle policies for images that are rarely accessed but need to be available.
- ✗
Hot tier.
Why it's wrong here
The Hot tier is optimized for high-frequency access, with the highest storage cost per GB among the live access tiers and lower per-transaction charges. If the images are only read occasionally, you would be paying a premium for storage capacity that sits idle between accesses. While data is always immediately available, the overall cost for infrequent access is excessive compared with Cool, making Hot the wrong choice for a cost-conscious workload where images are not accessed on a regular basis.
Go deeper
Related to this question
About these practice questions
One of 795 original AZ-305 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This AZ-305 practice question is part of Courseiva's free Microsoft certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the AZ-305 exam.