AZ-305 Design data storage solutions — 100 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?

Choose an answer to begin — your selection is scored in the full session.

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

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Azure SQL Database

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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

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Azure Files

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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

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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

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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

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Azure SQL Managed Instance

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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

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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

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Azure Redis Cache Premium tier

Answer

Azure Content Delivery Network

Question 11

A company is building a new application that requires a fully managed relational database. The application has varying workloads across different databases. The company wants to pool resources to optimize cost and allow each database to scale as needed. They also need automated backups with point-in-time restore and geo-replication for disaster recovery. Which Azure data service should they use?

Accepted Answer

Azure SQL Database. Azure SQL Database is a fully managed relational database service that supports elastic pools, which allow you to pool resources across multiple databases to optimize cost and enable each database to scale independently based on demand. It also provides automated backups with point-in-time restore (PITR) and active geo-replication for disaster recovery, meeting all the stated requirements.

Answer

Azure SQL Managed Instance

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Azure Database for MySQL

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Azure Database for PostgreSQL

Question 12

A global IoT platform ingests telemetry data from millions of devices. The application requires multi-region writes to support low-latency ingestion from any location. The schema uses JSON documents and fields often vary. The team needs automatic conflict resolution when the same document is updated concurrently from different regions. Additionally, read operations for device commands must use strong consistency, while user-facing dashboard queries can use eventual consistency. Which Azure Cosmos DB configuration should they choose?

Accepted Answer

Azure Cosmos DB with multi-master and per-request consistency override. The scenario requires multi-region writes (multi-master) and strong consistency for device command reads. In Azure Cosmos DB, strong consistency is not available for multi-region write accounts; the highest consistency level for multi-master is bounded staleness. Additionally, per-request consistency override only allows relaxing (weakening) the consistency for a specific request, not strengthening it to a level that the account does not support. Therefore, no configuration listed in the options can meet the strong consistency requirement with multi-master writes. A valid solution would require separate accounts or alternative designs, but this is not represented in the options.

Answer

Azure Cosmos DB with single-master and multiple read regions

Answer

Azure Cosmos DB with multi-master and default strong consistency

Answer

Azure Cosmos DB with multi-master and eventual consistency only

Question 13

A company uses Azure SQL Database (Premium tier) for their application. They need to offload reporting queries to a read-only copy of the database to reduce load on the primary. The read-only copy must be kept in sync synchronously within the same Azure region. They also need automated failover to the read-only copy if the primary fails. Which Azure SQL Database feature should they enable?

Accepted Answer

Read Scale-Out. Read Scale-Out is the correct feature because it offloads reporting queries to a read-only replica that stays synchronously committed within the same Azure region. It also provides automated failover to the read-only replica if the primary database fails, meeting both the synchronous sync and failover requirements for Premium-tier Azure SQL Database.

Answer

Active geo-replication

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Auto-failover groups

Answer

Database copy

Question 14

A company needs to store massive amounts of unstructured data, such as images and videos, for a media processing application. The data must be accessible via REST APIs and support tiered storage for cost optimization. Which Azure storage solution should they use?

Accepted Answer

Azure Blob Storage. Azure Blob Storage is the correct choice because it is designed for massive amounts of unstructured data (images, videos) and provides REST API access via HTTP/HTTPS. It also supports tiered storage (Hot, Cool, Cold, Archive) to optimize costs based on data access patterns, making it ideal for media processing workloads. While Azure Data Lake Storage Gen2 also supports REST APIs and tiering, it adds a hierarchical namespace and is typically optimized for analytics workloads, not general media storage.

Answer

Azure Files

Answer

Azure Data Lake Storage Gen2

Answer

Azure Disk Storage

Question 15

A media company stores raw video files and processed output in Azure. These files are accessed via REST APIs by a processing application. After processing, the files are rarely accessed but must be retained. To minimize costs, the company wants to automatically move files to a cheaper storage tier after 30 days and archive them after 90 days. Which Azure storage solution and feature should they use?

Accepted Answer

Azure Blob Storage with lifecycle management policies. Azure Blob Storage with lifecycle management policies is correct because it allows you to define rules that automatically transition blobs from the hot tier to the cool tier after 30 days and then to the archive tier after 90 days. This directly meets the cost-minimization requirement for rarely accessed files that must be retained, as lifecycle management automates tier transitions without manual intervention.

Answer

Azure Files with snapshot schedules

Answer

Azure Disk Storage with incremental snapshots

Answer

Azure NetApp Files with snapshot policies

Question 16

A software company hosts 100 small Azure SQL databases for different clients. Each database has low average usage but experiences unpredictable spikes. The company wants to minimize costs while allowing each database to burst up to a maximum resource limit during spikes. They also need to easily add new databases without manual sizing. Which Azure SQL Database deployment option should they use?

Accepted Answer

Elastic pools. Elastic pools allow multiple databases with low average usage and unpredictable spikes to share a fixed pool of resources (eDTUs or eVCores), enabling each database to burst up to a maximum limit while minimizing overall cost. This model also supports easy addition of new databases without manual sizing, as they are simply added to the pool and share its allocated resources.

Answer

Single databases with DTU-based tiers

Answer

Managed Instance

Answer

Hyperscale single database

Question 17

A company runs a global e-commerce application that needs to store product catalog data. The data is JSON documents with variable schemas. The application requires single-digit millisecond read and write latencies at any scale and must support automatic synchronous replication across multiple Azure regions for high availability and low latency reads from any region. Which Azure data service should they choose?

Accepted Answer

Azure Cosmos DB with multi-region writes. Azure Cosmos DB is the best choice because it natively supports JSON documents with variable schemas and guarantees single-digit millisecond response times. It provides automatic multi-region replication via multiple write regions, enabling active-active configuration for high availability and low-latency reads from any region. However, note that multi-region writes replicate asynchronously, not synchronously; the stem's use of 'synchronous replication' is inaccurate.

Answer

Azure SQL Database with active geo-replication

Answer

Azure Table Storage

Answer

Azure Database for PostgreSQL with read replicas

Question 18

A company runs a SQL Server database on an Azure virtual machine in a single region. They need to increase storage capacity and improve I/O performance for their transaction-intensive workload. They also want to ensure high availability within the same datacenter (99.99% SLA). What should they do?

Accepted Answer

Deploy the SQL Server on an availability set and use Storage Spaces Direct with multiple disks.. To achieve 99.99% availability within a single datacenter, you need multiple VMs in an availability set. Option C combines an availability set with Storage Spaces Direct (S2D), which uses multiple disks across VMs to provide both performance (through disk pooling) and high availability (via mirroring). This meets all requirements: increased storage capacity, improved I/O performance, and 99.99% SLA. Option A only addresses disk performance and redundancy but fails to provide VM-level redundancy, which is necessary for the SLA.

Answer

Use Azure Premium SSD v2 managed disks in a storage pool with mirroring across multiple disks.

Answer

Use Azure Ultra Disk storage attached to the VM.

Answer

Enable Azure SQL Managed Instance with auto-failover groups.

Question 19

A company wants to migrate its on-premises file server to Azure. The application accesses files using the Server Message Block (SMB) protocol and requires identity-based access integrated with on-premises Active Directory Domain Services (AD DS). The solution must be fully managed and provide low latency for users within the same region. Which Azure solution should they choose?

Accepted Answer

Azure Files with Active Directory authentication and Azure File Sync.. Azure Files with Active Directory authentication and Azure File Sync is the correct choice because it provides a fully managed SMB file share that supports identity-based access using on-premises AD DS. Azure File Sync enables caching of frequently accessed files on-premises or in Azure, reducing latency for users in the same region while maintaining a single namespace. This solution meets all requirements: SMB protocol, identity-based access, fully managed service, and low latency.

Answer

Azure NetApp Files with SMB volumes.

Answer

Azure Blob Storage with NFS 3.0 support.

Answer

Azure Managed Disk with a file server VM.

Question 20

A company ingests IoT sensor data into Azure Blob Storage. Data is written frequently and accessed rarely after the first 24 hours. The company must retain the data for exactly 90 days for compliance. They want to minimize storage costs by automatically moving data to cheaper tiers as soon as possible. Which lifecycle management policy should they implement?

Accepted Answer

Move to Cool tier after 1 day and then to Archive after 30 days. It aligns with the access pattern: data is frequently accessed only in the first 24 hours, so moving to Cool tier after 1 day (when access drops) saves costs, then moving to Archive after 30 days meets the 90-day retention requirement while minimizing storage costs. The lifecycle policy must ensure data is not moved to Archive before the compliance period ends, and moving to Cool immediately (0 days) would incur unnecessary write costs for frequently written data.

Answer

Move to Cool tier immediately (0 days) and then to Archive after 30 days

Answer

Move to Archive tier after 1 day

Answer

Move to Cool tier after 30 days and to Archive after 90 days