AZ-305 Design data storage solutions — 100 Questions

Question 1

A multinational company stores large amounts of unstructured data (documents, images) that must be read with low latency from multiple global regions. Data is written primarily in one region but read globally. Cost optimization is a key requirement. Which Azure storage replication option should they use?

Accepted Answer

Azure Blob Storage with read-access geo-redundant storage (RA-GRS). B is correct because RA-GRS provides geo-redundant storage with read access to the secondary region, enabling low-latency reads from multiple global regions while maintaining cost efficiency. The data is written primarily in one region, but RA-GRS allows read requests to be served from the secondary region without additional compute costs, meeting the global read requirement.

Answer

Azure Blob Storage with geo-redundant storage (GRS)

Answer

Azure Files with premium shares

Answer

Azure NetApp Files

Question 2

A startup is building a social media analytics platform that processes streaming data. They need a data store for time-series events with high write throughput and fast timestamp-based range queries. Which Azure data store is most suitable for this workload?

Accepted Answer

Azure Table Storage. Azure Table Storage is a NoSQL key-value store that supports high-volume, low-latency writes and efficient range queries on the PartitionKey and RowKey, which can be structured as a timestamp for time-series data. Its schema-less design and ability to scale to massive throughput without sharding overhead make it ideal for streaming event ingestion and timestamp-based retrieval.

Answer

Azure Cosmos DB with SQL API

Answer

Azure SQL Database with columnstore index

Answer

Azure Data Lake Storage Gen2

Question 3

A company ingests millions of IoT events per second from sensors around the world. Each event is a JSON message with timestamp, device ID, and readings. They need to support real-time analytics dashboards and also store all raw data for long-term historical analysis. They want to minimize operational overhead. Which Azure data storage solution should they recommend?

Accepted Answer

Azure Event Hubs with Capture to Azure Data Lake Storage.. Azure Event Hubs is designed for high-throughput data ingestion, capable of handling millions of events per second. By enabling the Capture feature, data is automatically and durably persisted to Azure Data Lake Storage in Avro format, providing a serverless, low-latency pipeline for real-time dashboards while storing raw data for long-term analytics. This minimizes operational overhead by eliminating the need to manage separate ingestion and storage infrastructure.

Answer

Azure Data Lake Storage Gen2 for all data.

Answer

Azure Cosmos DB for both real-time and historical data.

Answer

Azure Time Series Insights (TSI) Standard.

Question 4

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?

Accepted Answer

Premium SSD v2 disks for the database and Azure Files premium tier for the file share.. Premium SSD v2 disks can deliver up to 80,000 IOPS per disk, easily meeting the 50,000 IOPS requirement for the SQL Server database. Azure Files premium tier uses SSD-backed storage and provides consistent low-latency performance suitable for a shared file system, replacing the on-premises NAS. This combination directly maps the SAN (block) and NAS (file) workloads to Azure's highest-performance managed disks and file shares.

Answer

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

Answer

Ultra Disk for the database and Azure Files standard tier for the file share.

Answer

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

Question 5

A company needs a fully managed NoSQL database for a JSON document-oriented application that requires low latency (single-digit milliseconds) for reads and writes at any scale. The application will run globally and needs multi-region writes with automatic failover. Which Azure data store should they use?

Accepted Answer

Azure Cosmos DB. Azure Cosmos DB is the correct choice because it is a fully managed NoSQL database that natively supports JSON documents, offers single-digit millisecond latency for reads and writes at any scale, and provides multi-region writes with automatic failover through its multi-master replication capability. Its global distribution model allows you to configure multiple write regions, ensuring high availability and low latency worldwide.

Answer

Azure Table Storage

Answer

Azure SQL Database

Answer

Azure Cache for Redis

Question 6

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 7

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 8

A company wants to store raw data from IoT devices, social media feeds, and transactional databases for analytics. They need a storage solution that supports a hierarchical namespace for organizing data into directories and allows fine-grained access control at the directory and file level. They also need to query the data using Azure Synapse Analytics in-place. Which Azure storage solution should they use?

Accepted Answer

B. Azure Data Lake Storage Gen2 (ADLS Gen2) is the correct choice because it provides a hierarchical namespace that organizes data into directories and subdirectories, supports POSIX-like fine-grained access control at the directory and file level via ACLs, and can be queried in-place by Azure Synapse Analytics using its built-in serverless SQL pool or dedicated SQL pool. This combination of hierarchical namespace, granular security, and direct analytics integration makes it ideal for the described raw data storage and analytics scenario.

Answer

A

Answer

C

Answer

D

Question 9

A company runs a line-of-business application on Azure VMs that requires a highly available, low-latency SMB file share with support for active-active access from multiple VMs. The application requires high IOPS and throughput, and the file share must be mountable on both Linux and Windows VMs. Which Azure file storage solution should they recommend?

Accepted Answer

B. Azure Premium File Shares (using SMB 3.0 protocol) provide a fully managed, highly available SMB file share with low latency and high IOPS/throughput. They support active-active access from multiple VMs and can be mounted on both Linux and Windows VMs, meeting all the requirements.

Answer

A

Answer

C

Answer

D

Question 10

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

Answer

Azure SQL Database

Answer

Azure Redis Cache

Question 11

A media company stores large video files that are accessed once a month for audits. When needed, they must be available for download immediately (within seconds). The company wants to minimize storage costs. Which Azure Blob Storage access tier should they use?

Accepted Answer

Cool tier. The Cool tier is optimal for this scenario because it balances low storage cost with high availability and low latency access. Video files accessed once a month for audits require immediate download (within seconds), which Cool tier supports with the same millisecond latency as Hot tier, but at a lower storage price. Archive tier would introduce a multi-hour rehydration delay, making it unsuitable for on-demand access within seconds.

Answer

Hot tier

Answer

Cold tier

Answer

Archive tier

Question 12

A startup is building a new mobile app backend. They need a fully managed relational database service with built-in high availability, automatic backups, and built-in intelligence to optimize performance. They want to minimize administrative overhead for tasks like patching and scaling. Which Azure service should they use?

Accepted Answer

Azure SQL Database. Azure SQL Database is a fully managed Platform-as-a-Service (PaaS) relational database that includes built-in high availability (99.99% SLA), automatic backups with point-in-time restore, and built-in intelligence features like automatic tuning, adaptive query processing, and intelligent insights. This minimizes administrative overhead for patching, scaling, and performance optimization, making it ideal for a startup that wants to focus on app development rather than database management.

Answer

SQL Server on Azure Virtual Machines

Answer

Azure Database for MySQL

Answer

Azure Cosmos DB

Question 13

A company needs a data storage solution for a global application that frequently accesses recent data and less frequently older data. Data is unstructured blobs. They want to automatically move blobs to cool storage after 30 days and to archive storage after 90 days. Additionally, blobs must be retained for 7 years and cannot be deleted or modified during that period. Which Azure Blob Storage features should they combine?

Accepted Answer

Use blob lifecycle management policies and time-based retention policies.. Option B is correct because blob lifecycle management policies automatically transition blobs from hot to cool after 30 days and to archive after 90 days, while time-based retention policies enforce immutability for a fixed period (7 years), preventing deletion or modification. This combination meets both the tiering and retention requirements without manual intervention.

Answer

Use blob lifecycle management policies and legal hold (immutable blobs).

Answer

Use Azure Storage Analytics and immutability policies.

Answer

Use Azure File Sync and lifecycle management.

Question 14

A company needs a fully managed NoSQL database for a new application with a key-value and document data model. They require single-digit millisecond latency at any scale, multi-region writes with automatic conflict resolution, and a serverless capacity option to handle unpredictable traffic. Which Azure data service should they use?

Accepted Answer

Azure Cosmos DB. Azure Cosmos DB is the correct choice because it is a fully managed NoSQL database that supports both key-value and document data models natively. It guarantees single-digit millisecond latency at any scale, offers multi-region writes with automatic conflict resolution via its multi-master replication, and provides a serverless capacity mode that automatically scales based on demand, making it ideal for unpredictable traffic.

Answer

Azure Table Storage

Answer

Azure Cache for Redis

Answer

Azure SQL Database

Question 15

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 16

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 17

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 18

A company needs to store large amounts of unstructured data (log files) for analytics. The data is accessed frequently for the first 30 days, then occasionally for the next 90 days, and rarely after that but must be retained for 7 years for compliance. The data must not be modified or deleted during the retention period, and administrative access must not be able to bypass this restriction. They want to minimize storage costs. Which combination of Azure Blob Storage features should they configure?

Accepted Answer

Configure a lifecycle management policy to move blobs to Cool tier after 30 days and to Archive tier after 120 days. Apply a time-based retention policy with a retention period of 2,555 days and lock it.. Option A is correct because it combines a lifecycle management policy to automatically transition blobs from Hot to Cool after 30 days and to Archive after 120 days, minimizing storage costs. The time-based retention policy with a locked retention period of 2,555 days (7 years) ensures that blobs cannot be modified or deleted during the retention period, and locking the policy prevents administrative bypass, meeting the compliance requirement.

Answer

Enable soft delete and versioning on the storage account, and use a custom script to delete blobs after 7 years. Manually move blobs to Cool and Archive tiers using Azure PowerShell.

Answer

Set each blob's access tier to Cool on upload, then manually change to Archive after 30 days. Enable Azure Backup on the storage account for retention.

Answer

Apply a legal hold on the container to prevent deletion, and configure a lifecycle policy to move blobs to Archive after 30 days.

Question 19

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.. Azure Cosmos DB with multi-region writes enabled and the SQL (Core) API meets all requirements: it supports multi-region writes with automatic conflict resolution (last-writer-wins or custom), offers single-digit millisecond latency for reads and writes from any region, and uses a flexible JSON document schema. The ability to enforce strong consistency for critical operations like order placement via RequestOptions (using session or strong consistency at the request level) while allowing eventual consistency for less critical reads directly addresses the mixed consistency needs.

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 20

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