DP-900 Practice Test 21 — 15 Questions

Question 1

A media company stores large video files in Azure Blob Storage. The videos are accessed frequently for the first 30 days after upload, then rarely for the next 180 days. After that, they are only needed for compliance and are never accessed. Which access tier should be used for the first 30 days to minimize costs while maintaining low latency?

Accepted Answer

Hot tier. The Hot tier is the correct choice for the first 30 days because it provides the lowest latency access and highest throughput for frequently accessed data, which matches the requirement of frequent access during this period. While the Hot tier has the highest storage cost per GB, it has no retrieval costs, making it cost-effective for high-access patterns. The other tiers introduce either retrieval fees (Cool), high latency (Archive), or unnecessary cost (Premium) for this use case.

Answer

Cool tier

Answer

Archive tier

Answer

Premium tier

Question 2

A retail company plans to store product catalog data that includes product ID, name, description, price, and a varying set of attributes (e.g., size, color, material). The application requires low-latency reads and writes, global distribution, and the ability to handle schema flexibility. Which Azure data store is best suited for this workload?

Accepted Answer

Azure Cosmos DB. Azure Cosmos DB is the best choice because it provides low-latency reads and writes (single-digit milliseconds at the 99th percentile), global distribution with multi-region writes, and automatic schema flexibility through its document model. It supports varying product attributes (e.g., size, color, material) without requiring schema changes, and its turnkey global distribution ensures data is replicated across regions for fast access.

Answer

Azure SQL Database

Answer

Azure Table Storage

Answer

Azure Blob Storage

Question 3

A retail company uploads daily sales data from all stores to Azure Blob Storage at midnight. They then run a series of data transformations using Azure Data Factory on a scheduled trigger at 2:00 AM. This processing pattern is best described as:

Accepted Answer

Batch processing. This pattern is batch processing because the sales data is collected in Azure Blob Storage over a period (daily) and then processed as a group at a scheduled time (2:00 AM) using Azure Data Factory. Batch processing is designed for high-volume, periodic data loads where latency is acceptable, and the transformation job runs on a complete dataset rather than individual records.

Answer

Stream processing

Answer

Transactional processing

Answer

Interactive query

Question 4

A retail company runs its legacy order management application on an on-premises SQL Server. They plan to migrate to Azure with minimal application changes and need high availability with automatic failover to a secondary Azure region. They also require full database-level isolation and the ability to use SQL Server Agent jobs. Which Azure deployment option should they choose?

Accepted Answer

Azure SQL Managed Instance. Azure SQL Managed Instance (C) is correct because it provides near-100% compatibility with on-premises SQL Server, including full database-level isolation (a dedicated instance) and full support for SQL Server Agent jobs. It also supports auto-failover groups for high availability with automatic failover to a secondary Azure region, meeting the migration requirement with minimal application changes.

Answer

Azure SQL Database single database

Answer

Azure SQL Database elastic pool

Answer

SQL Server on Azure Virtual Machine

Question 5

A media company stores raw video footage as blobs in Azure Blob Storage. After processing, the raw footage is kept for compliance purposes and is accessed only a few times per year. The company wants to minimize storage costs while ensuring the data is durable and can be restored within 24 hours if needed. Which Azure Blob Storage access tier should they use?

Accepted Answer

Archive. The Archive tier is the correct choice because it offers the lowest storage cost for data that is rarely accessed (a few times per year) and can tolerate a retrieval latency of up to 15 hours, which is well within the 24-hour restoration requirement. Azure Blob Storage's Archive tier is designed for long-term retention, compliance, and backup scenarios where durability is maintained through geo-redundant replication options, and data can be rehydrated to an online tier (e.g., Hot or Cool) within the specified time frame.

Answer

Hot

Answer

Cool

Answer

Cold

Question 6

A global social media platform allows users to like posts. The platform is designed to prioritize availability and partition tolerance over strong consistency across its globally distributed Azure Cosmos DB instance. When a user likes a post, the like count may not be immediately visible to all users, but it will eventually become consistent across all regions. Which consistency model does this application follow?

Accepted Answer

Eventual consistency. Eventual consistency is the correct choice because the platform prioritizes availability and partition tolerance (AP from the CAP theorem) over strong consistency. In Azure Cosmos DB, eventual consistency guarantees that all replicas will converge to the same value over time without any ordering guarantees, which matches the scenario where like counts are not immediately visible but become consistent eventually.

Answer

Strong consistency

Answer

Bounded staleness consistency

Answer

Session consistency

Question 7

A manufacturing company installs IoT sensors on equipment in a factory. Each sensor sends a reading (device ID, timestamp, temperature, vibration) every second. The application must store these readings with extremely low write latency, support queries for the latest reading per device, and allow range queries over the last hour for a specific device. The development team expects high throughput writes (millions per day) and does not require complex joins. Which Azure data store is most appropriate for this workload?

Accepted Answer

Azure Cosmos DB. Azure Cosmos DB is the most appropriate because it offers single-digit millisecond write and read latencies at any scale, which is critical for the high-throughput, low-latency IoT sensor ingestion described. Its support for automatic indexing and efficient point reads (by device ID and timestamp) enables fast retrieval of the latest reading per device, while its native time-to-live (TTL) and range query capabilities on the timestamp field allow efficient queries over the last hour for a specific device. Additionally, Cosmos DB's schema-agnostic, non-relational model fits the simple key-value structure of sensor readings without requiring complex joins.

Answer

Azure Table Storage

Answer

Azure Blob Storage

Answer

Azure SQL Database

Question 8

A global e-commerce company needs to store user session data (key-value pairs) for a web application hosted in multiple Azure regions. The data must support low-latency reads and writes (under 10 ms) and be automatically replicated across regions for high availability. The development team also requires the ability to query sessions by user ID using a simple key lookup and occasionally filter by secondary attributes such as timestamp. Which Azure data store should they choose?

Accepted Answer

Azure Cosmos DB. Azure Cosmos DB is correct because it provides globally distributed, multi-region writes with automatic replication, guaranteeing low-latency reads and writes under 10 ms at the 99th percentile. Its key-value API (Table API or SQL API) supports simple key lookups by user ID and secondary indexing on attributes like timestamp, meeting all stated requirements.

Answer

Azure Table Storage

Answer

Azure SQL Database

Answer

Azure Cache for Redis

Question 9

A mobile gaming startup needs to store player profiles that can have varying attributes (e.g., some players have a 'nickname', others have 'avatar URL'). The application must read a player's profile by PlayerID with very low latency (under 10 ms) from any location worldwide. The data does not require complex queries or joins. Which Azure data store should they choose?

Accepted Answer

Azure Cosmos DB. Azure Cosmos DB is the correct choice because it is a globally distributed, multi-model database service that guarantees single-digit-millisecond read latencies (under 10 ms) at any scale from any Azure region. Its schema-agnostic nature allows storing player profiles with varying attributes (e.g., nickname, avatar URL) without requiring a fixed schema, and it supports point reads by PlayerID with a consistency model that can be tuned for performance. This directly matches the requirements of low-latency global reads and flexible, non-relational data.

Answer

Azure SQL Database

Answer

Azure Table Storage

Answer

Azure Blob Storage

Question 10

A retail application uses Azure SQL Database. The Products table contains 200,000 rows with columns: ProductID (primary key, clustered), CategoryID, ProductName, Price, StockQuantity. Queries frequently filter on CategoryID and then sort results by Price in descending order. Which indexing strategy will most improve query performance for these operations?

Accepted Answer

Create a nonclustered index on (CategoryID, Price) with Price in descending order.. Option C creates a composite nonclustered index on (CategoryID, Price DESC) that directly supports both the filter (CategoryID equality) and the sort (Price descending) in a single index seek and ordered scan, eliminating the need for a separate sort operation. This is the most efficient strategy because the index is ordered exactly as the query requires, allowing SQL Server to retrieve matching rows in the correct order without additional processing.

Answer

Create a clustered index on CategoryID.

Answer

Create a nonclustered index on CategoryID that includes Price as an included column.

Answer

Create a clustered columnstore index on the table.

Question 11

A global social media platform stores user profile images (JPEG) and activity logs in JSON format. The logs have varying structures based on the type of activity. The application requires low-latency reads of images from any region and the ability to query logs using SQL-like syntax. Which Azure data storage solution should they use for each data type?

Accepted Answer

Azure Blob Storage with a CDN for images and Azure Cosmos DB (SQL API) for logs. Azure Blob Storage is optimized for storing large binary objects like JPEG images, and integrating it with Azure CDN ensures low-latency reads globally by caching content at edge nodes. Azure Cosmos DB with the SQL API provides native support for querying JSON documents with varying schemas using SQL-like syntax, making it ideal for the activity logs.

Answer

Azure Table Storage for images and Azure Cosmos DB (Table API) for logs

Answer

Azure Files for images and Azure SQL Database for logs

Answer

Azure Disk Storage for images and Azure Cosmos DB (MongoDB API) for logs

Question 12

A global online gaming company needs a data store for player game session logs. Each log record has a SessionID (unique), PlayerID, GameID, StartTime, EndTime, and a JSON payload containing variable game state details. The company requires low-latency writes for millions of concurrent sessions and wants to query by PlayerID and time range. Schema flexibility is important because game state details change frequently. Which Azure data store should they choose?

Accepted Answer

Azure Cosmos DB with the NoSQL API. Azure Cosmos DB with the NoSQL API is the correct choice because it provides low-latency writes (single-digit milliseconds at the 99th percentile) for millions of concurrent sessions, supports schema-flexible JSON documents that can accommodate frequently changing game state payloads, and enables efficient queries by PlayerID and time range using a composite index or a partition key like PlayerID combined with a time-based sort order.

Answer

Azure Table Storage

Answer

Azure Blob Storage

Answer

Azure SQL Database

Question 13

A global e-commerce platform uses Azure Cosmos DB to store product inventory data. Customers add items to their cart, which reduces the available inventory count. The application requires that after a customer adds an item, any subsequent read of that product's inventory from any region in the world must reflect the reduced count immediately. Which Cosmos DB consistency level should be used?

Accepted Answer

Strong consistency. Strong consistency ensures that any read operation returns the most recent write, regardless of the region. Since the application requires that after a customer adds an item, any subsequent read of that product's inventory from any region must reflect the reduced count immediately, Strong consistency is the only level that guarantees linearizability and zero staleness across all replicas.

Answer

Eventual consistency

Answer

Consistent prefix consistency

Answer

Session consistency

Question 14

A retail company runs an e-commerce platform on a single SQL Server database. The database experiences unpredictable spikes in read-only reporting queries that degrade transactional performance. They want to migrate to Azure SQL Database and isolate the reporting workload while ensuring it sees the most current data. Which feature should they enable?

Accepted Answer

Read Scale-out (using a readable secondary). Read Scale-out allows you to offload read-only reporting queries to a readable secondary replica, isolating them from the primary transactional workload. This ensures reporting queries see the most current data because the secondary replica is kept transactionally consistent with the primary via synchronous replication. It directly addresses the unpredictable spikes in read-only queries without degrading transactional performance.

Answer

Elastic Pool

Answer

Geo-replication

Answer

SQL Server Agent

Question 15

A social media application stores user profiles as JSON documents. Each user profile can have different attributes (e.g., some have 'education', others have 'work experience'). The application needs to query profiles by any attribute with low latency. Which Azure data store is most appropriate?

Accepted Answer

Azure Cosmos DB (SQL API). Azure Cosmos DB with the SQL API is the correct choice because it natively supports schema-agnostic JSON documents, allowing each user profile to have varying attributes without requiring a fixed schema. Its indexing policies enable low-latency queries on any attribute, and it provides single-digit millisecond response times for point reads and queries, which is essential for a social media application.

Answer

Azure Blob Storage

Answer

Azure Table Storage

Answer

Azure SQL Database