DP-900 Practice Question: Describe considerations for working with non-relational data on Azure
Which TWO of the following are features of Azure Cosmos DB that help ensure high availability?
⚠ Common exam trap
DP-900 often tests the confusion between availability features (failover, multi-region writes) and durability/security features (encryption, backup, change feed) — candidates who pick encryption or point-in-time restore mistake protection for uptime.
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
✓
Automatic failover
Automatic failover (C) is a core Cosmos DB high-availability feature: when a region becomes unavailable, Cosmos DB automatically promotes a secondary replica/region to primary without manual intervention, keeping the account writable and readable. Multi-region writes (E) enable every configured region to accept writes in an active-active configuration, so a workload can continue writing even if one region fails, and it also reduces write latency. Together these features directly address continuous availability and regional resilience. Data encryption at rest (A) protects stored data confidentiality but does not provide availability during a regional outage. Change feed (B) is a mechanism for reading a continuous, ordered log of item changes for downstream processing, not for availability. Point-in-time restore (D) is a backup/recovery capability that restores data to an earlier state, which addresses data loss recovery rather than keeping the database available.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Data encryption at rest
Why it's wrong here
Data encryption at rest is a security control that uses AES-256 to protect stored data, ensuring confidentiality and compliance with regulatory standards. However, it does not affect the availability of the database during a regional outage or failover event. Encryption at rest is about preventing unauthorized access to the physical storage, not about keeping the service running or mitigating downtime, so it is not a high-availability feature.
- ✗
Change feed
Why it's wrong here
The change feed is an event-driven mechanism that tracks item-level inserts, updates, and deletes, allowing you to react to changes or integrate with downstream systems. While it can enable patterns like event sourcing or replication to other stores, it does not provide any redundancy, automatic failover, or continued operations if a region becomes unavailable. The change feed is about processing data changes, not about sustaining availability, so it is irrelevant to high availability concerns.
- ✓
Automatic failover
Why this is correct
Automatic failover is a core high-availability feature in Azure Cosmos DB that continuously monitors the health of regions and, if the primary region becomes unavailable, automatically redirects traffic to a secondary region without manual intervention. This ensures that the database remains accessible and can continue to serve read and write requests (depending on the consistency configuration) during an outage. It directly addresses the need for uptime and resilience, which makes it a correct answer for a high-availability question.
- ✗
Point-in-time restore
Why it's wrong here
Point-in-time restore is a backup and recovery feature designed to protect against accidental data corruption, human error, or malicious deletions by allowing you to restore the database to an earlier state, typically with a granularity of seconds. However, performing a restore usually involves replacing the current database with the restored version, which can cause downtime or require redirecting applications to a new database endpoint. It is fundamentally a disaster-recovery feature for data integrity, not a proactive mechanism for maintaining continuous availability, so it does not qualify as a high-availability feature.
- ✓
Multi-region writes
Why this is correct
Multi-region writes is a high-availability feature because it allows every region in a Cosmos DB account to accept both reads and writes, with data replicated synchronously across all regions. If one region experiences an outage, the remaining regions continue to handle read and write traffic without interruption, effectively removing a single point of failure. This capability directly enhances availability and is a correct answer for a question about high availability, often enabling a 99.999% uptime SLA.
Go deeper
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Azure Database for MySQL
Key term
Data
Data is raw, unprocessed information, like numbers, words, or measurements, that can be stored, processed, and analyzed by computers.
Key term
Azure Cosmos DB
Azure Cosmos DB is a fully managed, globally distributed NoSQL database service that offers fast reads and writes anywhere in the world with automatic scaling and multiple consistency models.
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Microsoft exam blueprint
This DP-900 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 DP-900 exam.