DP-900 Practice Test 8 — 10 Questions

Question 1

A media company stores large video files and associated metadata (title, duration, tags) as JSON documents. The application requires low-latency streaming of videos to users worldwide and the ability to quickly query metadata by tag. Which combination of Azure services should the company use?

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

Accepted Answer

Azure Blob Storage for videos and Azure Cosmos DB for metadata. Azure Blob Storage is optimized for storing large binary objects like video files, offering high-throughput streaming via HTTP/HTTPS and integration with CDN for low-latency global delivery. Azure Cosmos DB provides single-digit millisecond read and write latencies with automatic indexing, making it ideal for quickly querying JSON metadata by tag using SQL or MongoDB API. This combination separates storage concerns (blobs for raw video, document DB for structured metadata) to meet both streaming and query performance requirements.

Answer

Azure Blob Storage for both videos and metadata

Answer

Azure Cosmos DB for videos and Azure Table Storage for metadata

Answer

Azure Files for videos and Azure SQL Database for metadata

Question 2

A manufacturing company collects sensor data from factory equipment as a continuous stream of events ingested into Azure Event Hubs. Additionally, the company receives daily inventory CSV files uploaded to Azure Data Lake Storage Gen2. The analytics team needs to build near real-time dashboards that combine streaming sensor data with batch inventory data, and also support historical reporting by querying data directly in the data lake using SQL without moving it. Which Azure service should they choose as the primary analytics platform?

Accepted Answer

Azure Synapse Analytics. Azure Synapse Analytics is the correct choice because it provides a unified analytics platform that can ingest both real-time streaming data from Azure Event Hubs and batch data from Azure Data Lake Storage Gen2. Its SQL Serverless feature allows querying data directly in the data lake using T-SQL without moving it, enabling near real-time dashboards and historical reporting in a single service.

Answer

Azure Stream Analytics

Answer

Azure Data Factory

Answer

Azure HDInsight with Spark

Question 3

A data analyst needs to run ad-hoc SQL queries on petabytes of log data stored as Parquet files in Azure Data Lake Storage Gen2. The queries join multiple tables and require high concurrency from multiple analysts. The solution should minimize cost by only paying for queries executed. Which Azure service should they use?

Accepted Answer

Azure Synapse Serverless SQL pool. Azure Synapse Serverless SQL pool is the correct choice because it allows running ad-hoc T-SQL queries directly on Parquet files in Azure Data Lake Storage Gen2 without provisioning any infrastructure. It uses a pay-per-query billing model, making it cost-effective for sporadic, high-concurrency workloads where you only want to pay for the compute resources consumed during query execution.

Answer

Azure Synapse Dedicated SQL pool

Answer

Azure HDInsight with Spark

Answer

Azure Databricks

Question 4

A company uses Azure SQL Database to store customer order data. They need to automatically track changes to the 'OrderStatus' column in the 'Orders' table. They want to be able to query the current status and also easily retrieve historical status changes for a given order without writing custom triggers or history tables. Which feature should they enable?

Accepted Answer

Temporal tables. Temporal tables (system-versioned) automatically track full row history, including changes to the 'OrderStatus' column, by maintaining a paired history table. This allows querying both current and historical states with simple T-SQL clauses like FOR SYSTEM_TIME, without custom triggers or manual history tables.

Answer

Change Data Capture (CDC)

Answer

Automatic tuning

Answer

Geo-replication

Question 5

A mobile gaming company stores player activity logs as JSON documents. Each document has a unique ActivityID, a PlayerID, a timestamp, and a variable set of attributes depending on the game event (e.g., level started, item purchased). The application requires low-latency point reads by ActivityID and needs to query logs by PlayerID for a given time range. Schema flexibility is critical because new game events are added frequently. Which Azure Cosmos DB API should they choose?

Accepted Answer

NoSQL API (formerly SQL API). The NoSQL API (formerly SQL API) is the correct choice because it natively supports JSON documents with flexible schemas, enabling the variable attributes required for new game events. It provides low-latency point reads by ActivityID via direct partition key lookups and supports efficient queries by PlayerID within a time range using composite indexes or cross-partition queries with filtering. This API is optimized for schema-agnostic, document-based workloads and offers the richest query capabilities for JSON data in Azure Cosmos DB.

Answer

MongoDB API

Answer

Cassandra API

Answer

Gremlin API

Question 6

A bank processes a fund transfer that involves deducting money from one account and crediting it to another. The system ensures that both operations succeed together or, if any part fails, the entire transaction is rolled back, leaving both accounts unchanged. Which ACID property does this scenario primarily guarantee?

Accepted Answer

Atomicity. Atomicity ensures that a transaction is treated as a single, indivisible unit of work. In this fund transfer scenario, both the debit and credit operations must complete successfully, or the entire transaction is rolled back, leaving the accounts unchanged. This all-or-nothing behavior is the defining characteristic of atomicity in ACID transactions.

Answer

Consistency

Answer

Isolation

Answer

Durability

Question 7

A company uses Azure SQL Database for an order processing system. The Orders table has columns: OrderID (PK), CustomerID, OrderDate, TotalAmount. The Customers table has CustomerID (PK), Name, Email. The database administrator wants to ensure that when a customer record is deleted, all orders for that customer are also automatically deleted. Which database constraint should be implemented?

Accepted Answer

ON DELETE CASCADE on Orders.CustomerID. ON DELETE CASCADE on the foreign key (Orders.CustomerID) automatically deletes all child rows in the Orders table when the parent row in the Customers table is deleted. This ensures referential integrity without requiring additional code or triggers, and is the standard SQL mechanism for cascading deletes in Azure SQL Database.

Answer

ON DELETE SET NULL on Orders.CustomerID

Answer

ON UPDATE CASCADE on Customers.CustomerID

Answer

A trigger on Customers table

Question 8

A company's application uses Microsoft SQL Server with multiple databases that need to run complex queries joining tables across databases. They are migrating to Azure and need a fully managed relational database service with high availability, automated backups, and minimal management overhead. They do not need a separate SQL Server installation and want to avoid managing VMs. Which Azure deployment option should they choose?

Accepted Answer

Azure SQL Managed Instance. Azure SQL Managed Instance is the correct choice because it provides near-100% compatibility with on-premises SQL Server, including support for cross-database queries and linked servers, while being a fully managed platform-as-a-service (PaaS) offering. It eliminates the need to manage VMs or a separate SQL Server installation, and it includes built-in high availability (99.99% SLA) and automated backups, meeting all stated requirements.

Answer

Azure SQL Database single database

Answer

SQL Server on Azure Virtual Machines

Answer

Azure SQL Database elastic pool

Question 9

A hospital stores patient vital signs data in Azure Cosmos DB. Each document contains PatientID, Timestamp, HeartRate, BloodPressure, and other measurements. The most common query retrieves all vital signs for a specific patient within a time range (e.g., last 24 hours). Which property should be chosen as the partition key to minimize Request Unit (RU) consumption and ensure even data distribution?

Accepted Answer

PatientID. PatientID is the ideal partition key because the most common query filters by PatientID and a time range. With PatientID as the partition key, Cosmos DB can route the query to a single physical partition containing all documents for that patient, minimizing cross-partition queries and reducing RU consumption. It also ensures even data distribution since each patient generates a similar volume of vital signs data, avoiding hot partitions.

Answer

Timestamp

Answer

HeartRate

Answer

BloodPressure

Question 10

A company needs to run complex SQL queries on petabytes of data stored in Azure Data Lake Storage Gen2. They want to pay only for the queries they run and do not want to manage any infrastructure. Which Azure service should they use?

Accepted Answer

Azure Synapse Serverless SQL pool. Azure Synapse Serverless SQL pool is the correct choice because it enables running complex SQL queries directly against data in Azure Data Lake Storage Gen2 without provisioning any infrastructure. It uses a pay-per-query billing model, charging only for the amount of data processed, which aligns with the requirement to pay only for queries run and avoid infrastructure management.

Answer

Azure Synapse dedicated SQL pool

Answer

Azure SQL Database

Answer

Azure HDInsight