AZ-900 Describe Azure architecture and services Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  Hot tier

  Why it's wrong here

  The Hot tier is optimized for data that is accessed or modified frequently, such as active production files or current application datasets. It provides the highest storage cost per gigabyte, but charges no retrieval penalty and offers the lowest access latency, making it suitable for workloads with high throughput. Selecting Hot for rarely accessed data would inflate storage costs without any offsetting benefit, so it fails when the goal is to minimize cost for cold data.

• ✗

  Cool tier

  Why it's wrong here

  The Cool tier is suited for data that is infrequently accessed and expected to remain stored for at least 30 days, offering storage costs lower than Hot but higher than Archive. It allows retrieval in seconds without rehydration, making it appropriate for short- to medium-term archives, but it still costs more per gigabyte than Archive and imposes early deletion penalties if data is removed before the minimum retention period. For data with a retention horizon of 180+ days and negligible access needs, Archive is more cost-effective, so Cool is not the correct answer.

• ✓

  Archive tier

  Why this is correct

  The Archive tier is designed for data that is rarely accessed and can accept a retrieval latency of up to several hours. It has the lowest storage cost per gigabyte among Azure Blob Storage access tiers, but data must be rehydrated to the Hot or Cool tier before reading, incurring additional time and fees. This makes Archive ideal for long-term retention, backup archives, or compliance data that requires minimal cost but does not need immediate access.

• ✗

  Standard tier

  Why it's wrong here

  The term 'Standard' in Azure Storage refers to a performance tier, not an access frequency tier; it indicates standard hardware (magnetic, HDD-based) as opposed to the 'Premium' performance tier that uses SSDs for consistent low latency. In the context of access tiers, 'Standard' is not a valid answer because Azure's cost-optimization options are named Hot, Cool, Cold, and Archive. Applying the performance-tier label to an access-frequency question is a category error, which makes this choice incorrect.

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