AZ-305 Design data storage solutions — Timed 10 Questions

Question 1

A company runs a legacy application on Azure Virtual Machines. The application uses a SQL Server database that requires 50,000 IOPS consistently. It also uses a shared file system for storing documents. They plan to migrate from on-premises where they used a SAN for block storage and NAS for file shares. Which combination of Azure storage should they use to meet performance requirements?

10 minute time limit — choose an answer to begin.

Accepted Answer

Premium SSD v2 disks for the database and Azure Files premium tier for the file share.. Premium SSD v2 and Ultra Disk both can deliver 50,000 IOPS on a single managed disk. The database performance requirement is the only stated performance requirement; the shared file system simply needs to be a NAS replacement, which Azure Files standard tier does. Therefore, option C also meets the requirements. The original explanation misleadingly singles out Premium SSD v2 as the only disk tier capable of 50,000 IOPS, ignoring Ultra Disk.

Answer

Premium SSD (non-v2) for the database and Azure NetApp Files for the file share.

Answer

Standard SSD for the database and Azure Blob Storage for the file share.

Question 2

A company needs to store and analyze petabytes of semi-structured data from IoT devices. The data is append-only and written in time order. They need to support fast queries on time ranges and also aggregate data in real-time. Which Azure data service should they use?

Accepted Answer

Azure Data Explorer. Azure Data Explorer (ADX) is purpose-built for high-performance analysis of large volumes of time-series and semi-structured data. It supports append-only ingestion, optimized time-range queries via its columnar storage and indexing, and real-time aggregation using Kusto Query Language (KQL) with built-in materialized views and update policies.

Answer

Azure Cosmos DB

Answer

Azure SQL Database

Answer

Azure Table Storage

Question 3

A company is building a big data analytics platform that will process structured, semi-structured, and unstructured data using Azure Synapse Analytics and other tools. They need a storage layer that supports hierarchical namespaces and fine-grained access control at the directory level. Which Azure storage solution should they use?

Accepted Answer

Azure Data Lake Storage Gen2. Azure Data Lake Storage Gen2 (ADLS Gen2) is the correct choice because it combines Azure Blob Storage with a hierarchical namespace, enabling directory-level access control lists (ACLs) and POSIX-compliant permissions. This is essential for the big data analytics platform described, as it must support structured, semi-structured, and unstructured data with fine-grained access control at the directory level, which Azure Synapse Analytics can directly query via ABFS (Azure Blob File System) driver.

Answer

Azure Blob Storage

Answer

Azure Files

Answer

Azure Cosmos DB

Question 4

A global e-commerce company needs a database solution that can handle high-velocity writes from user transactions across multiple regions. They require multi-region writes with automatic conflict resolution and single-digit millisecond latency for reads and writes. Which Azure data store should they use?

Accepted Answer

Azure Cosmos DB. Azure Cosmos DB is the correct choice because it offers multi-region writes with automatic conflict resolution using last-writer-wins (LWW) or custom conflict resolution policies, and it guarantees single-digit millisecond latency for both reads and writes at the 99th percentile. Its globally distributed, multi-model design is purpose-built for high-velocity transactional workloads that require active-active replication across regions.

Answer

Azure Table Storage

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Azure SQL Database

Answer

Azure Redis Cache

Question 5

A financial company must store customer transaction records in Azure Blob Storage. Regulatory requirements mandate that the records must not be modified or deleted for 7 years. Even administrators must be unable to alter or remove the blobs during this period. Which Azure Blob Storage feature should they enable?

Accepted Answer

Immutable storage with time-based retention policy. Immutable storage with a time-based retention policy (WORM – Write Once, Read Many) ensures that blobs cannot be modified or deleted for a specified duration, even by administrators. This directly satisfies the 7-year regulatory requirement by locking the data at the storage level, overriding any delete or write operations.

Answer

Legal hold

Answer

Soft delete

Answer

Versioning

Question 6

A company has 10 branch offices, each with Windows file servers. They want to centralize file storage in Azure and allow each branch office to cache files locally for fast access. The solution must support cloud tiering so that only frequently accessed files are kept locally. Which Azure service should they implement?

Accepted Answer

Azure File Sync. Azure File Sync is the correct choice because it enables centralizing file shares in Azure Files while providing local caching on Windows file servers at each branch office. It supports cloud tiering, which automatically keeps only frequently accessed files locally and moves cold data to the cloud, meeting the requirement for fast local access and efficient storage.

Answer

Azure Files

Answer

Azure Blob Storage with Azure File Sync

Answer

Azure NetApp Files

Question 7

A SaaS company uses Azure SQL Database for a multi-tenant application. They have 80 tenant databases, each with varying and unpredictable usage patterns. The company wants to optimize costs without sacrificing performance and wants the ability to easily add new tenant databases without over-provisioning. Which deployment option should they use?

Accepted Answer

Azure SQL Database elastic pool. Azure SQL Database elastic pool is the correct choice because it allows multiple tenant databases to share a fixed set of resources (DTUs or vCores), automatically absorbing the unpredictable usage spikes of individual tenants without over-provisioning. This model optimizes cost by paying for the pooled resources rather than each database's peak capacity, and new tenant databases can be added seamlessly to the pool without upfront resource allocation.

Answer

Single Azure SQL Database per tenant

Answer

Azure SQL Managed Instance

Answer

Azure SQL Database Hyperscale

Question 8

A global e-commerce platform requires a database that supports multi-region writes with automatic conflict resolution and single-digit millisecond latency for reads and writes from any region. The application uses a flexible schema with JSON documents. They also need to enforce strong consistency for critical operations (e.g., order placement) while allowing eventual consistency for less critical reads. Which Azure data service and configuration should they choose?

Accepted Answer

Azure Cosmos DB with multi-region writes enabled on the account, using the SQL (Core) API, and applying strong consistency for the order placement operation via RequestOptions.. The requirement for multi-region writes with automatic conflict resolution conflicts with strong consistency in Azure Cosmos DB. Strong consistency is only available for accounts with a single write region. Multi-region write accounts support at most bounded staleness consistency. Therefore, no Azure data service in the options can satisfy both multi-region writes and strong consistency for critical operations. Azure SQL Database geo-replication is single-primary, Azure Cache for Redis is not a document database, and Azure Table Storage lacks multi-master writes and flexible JSON document support. A correct solution would need to relax one of the requirements (e.g., use bounded staleness instead of strong consistency, or use a single-write region with strong consistency).

Answer

Azure SQL Database with active geo-replication across two regions and failover groups.

Answer

Azure Cache for Redis with geo-replication.

Answer

Azure Table Storage with geo-redundant storage (GRS) and read-access (RA-GRS).

Question 9

A company stores website static assets in Azure Blob Storage. The assets are updated weekly and must be available for immediate access for 30 days. After 30 days, older versions can be moved to the Cool tier to save costs but must still be accessible within seconds. They want an automated solution. What should they configure?

Accepted Answer

Use Azure Blob Storage lifecycle management rules. Azure Blob Storage lifecycle management rules allow you to automate tier transitions based on age or last modification time. By configuring a rule to move blobs to the Cool tier 30 days after creation, you meet the requirement for immediate access (Cool tier offers sub-second latency) while optimizing costs without manual intervention.

Answer

Set the access tier to Cool on the container

Answer

Manually change the access tier every 30 days

Answer

Use Azure Policy to enforce tier changes

Question 10

A company wants to cache frequently accessed session state and product data for their e-commerce website. They need the cache to be highly available with a 99.9% SLA and provide fast read and write access. The solution must be fully managed. Which Azure Cache tier should they choose?

Accepted Answer

Azure Redis Cache Standard tier. The Standard tier of Azure Redis Cache provides a 99.9% SLA through built-in replication with two nodes (primary and replica) in the same region, ensuring high availability. It is fully managed, supports fast read/write access for session state and product data, and meets the requirement without the additional cost or complexity of the Premium tier.

Answer

Azure Redis Cache Basic tier

Answer

Azure Redis Cache Premium tier

Answer

Azure Content Delivery Network