DP-900 Practice Test 50 — 15 Questions

Question 1

A multinational corporation has Azure SQL Databases deployed in multiple Azure regions. They need to ensure that a failover to a secondary region happens automatically and with minimal data loss if the primary region goes down. Which deployment option should they use?

Accepted Answer

Active geo-replication with auto-failover groups. Option D is correct because active geo-replication with auto-failover groups provides automatic failover across regions with RPO of 5 seconds. Option A is wrong because Azure SQL Database local redundancy protects within a region. Option B is wrong because Azure SQL Database zone redundancy protects within a region across zones. Option C is wrong because Azure Traffic Manager is for traffic routing, not database failover.

Answer

Zone-redundant database

Answer

Azure Traffic Manager with multiple databases

Answer

Locally redundant storage (LRS)

Question 2

A data engineering team at a logistics company handles two distinct data processing workloads. The first workload ingests GPS data from delivery trucks every 10 seconds and updates a dashboard showing real-time vehicle locations. The second workload processes monthly CSV files of completed deliveries to generate reports on delivery times and route efficiency. Which statement correctly identifies these workloads?

Accepted Answer

GPS data processing is a streaming workload; monthly report processing is a batch workload. C is correct because GPS data ingested every 10 seconds is a continuous, near-real-time stream, making it a streaming workload. Monthly CSV file processing is a classic batch workload, as data is collected over a period and processed in a single, scheduled job. This distinction is fundamental in Azure data services: streaming workloads use services like Azure Stream Analytics or Event Hubs, while batch workloads use Azure Synapse Pipelines or Azure Data Factory.

Answer

Both workloads are streaming workloads

Answer

GPS data processing is a batch workload; monthly report processing is a streaming workload

Answer

Both workloads are batch workloads

Question 3

A financial analytics company has two distinct data processing workloads. The first workload ingests real-time stock trade data from a message queue, calculates moving averages every minute, and updates a dashboard for traders. The second workload receives daily CSV files containing end-of-day trade summaries, transforms them using Python scripts, and loads the results into a data warehouse for monthly reporting. Which statement correctly characterizes these workloads?

Accepted Answer

First workload: Stream processing, Second workload: Batch processing. Option A is correct because the first workload processes real-time stock trade data from a message queue and calculates moving averages every minute, which is a classic stream processing pattern (continuous, low-latency data ingestion and computation). The second workload handles daily CSV files with end-of-day summaries, transforms them with Python scripts, and loads results into a data warehouse for monthly reporting, which is a classic batch processing pattern (scheduled, high-latency processing of bounded data sets).

Answer

First workload: Batch processing, Second workload: Stream processing

Answer

First workload: OLTP, Second workload: OLAP

Answer

First workload: Transactional processing, Second workload: Analytical processing

Question 4

A database system must ensure that when a transfer of funds between two accounts is processed, if the system crashes after debiting the first account but before crediting the second, the database automatically undoes the debit. This property is best described as:

Accepted Answer

Atomicity. Atomicity ensures that a transaction is treated as a single, indivisible unit of work. If the system crashes after debiting one account but before crediting the other, the database's transaction log records the partial changes, and during recovery, the database engine (e.g., SQL Server's ARIES recovery model) performs an automatic rollback of the uncommitted transaction, undoing the debit to maintain atomicity.

Answer

Consistency

Answer

Isolation

Answer

Durability

Question 5

A financial database system ensures that once a transaction is committed, the data changes are permanently stored and will survive any subsequent system failure, such as a power outage or crash. Which property of ACID transactions does this describe?

Accepted Answer

D: Durability. D is correct because durability guarantees that once a transaction is committed, the changes persist permanently, even in the event of a system failure like a power outage or crash. In SQL Server, this is implemented via the write-ahead log (WAL) and checkpoint processes, ensuring committed data is flushed to disk before acknowledging success.

Answer

A: Atomicity

Answer

B: Consistency

Answer

C: Isolation

Question 6

A healthcare application stores patient vital signs readings. Each reading is a JSON document with fields: PatientID, Timestamp, HeartRate, BloodPressure (systolic and diastolic). The application frequently queries for all readings of a specific patient within a time range, and the schema varies occasionally (e.g., new optional fields are added). How should this data be classified?

Accepted Answer

Semi-structured. The data is semi-structured because it is stored as JSON documents, which have a flexible schema that can vary between records (e.g., new optional fields can be added). JSON documents are self-describing and do not require a fixed schema like relational tables, but they still have organizational properties (fields like PatientID, Timestamp) that distinguish them from unstructured data like plain text or images. The application's queries on specific fields (PatientID, Timestamp) further confirm the data has structure, but the schema flexibility rules out structured or relational classifications.

Answer

Structured

Answer

Unstructured

Answer

Relational

Question 7

A financial company needs to store transactional records where each record has a fixed set of attributes (TransactionID, Amount, Date, AccountID). The data must support complex queries and enforce referential integrity. Which type of data store is most appropriate?

Accepted Answer

Relational database. A relational database (option C) is the most appropriate choice because transactional records with a fixed schema and the need for referential integrity (e.g., ensuring AccountID references a valid account) are best handled by a structured, ACID-compliant system like Azure SQL Database or SQL Server. Relational databases enforce constraints such as foreign keys and support complex queries using JOINs and aggregations, which are essential for financial reporting and auditing.

Answer

Key-value store

Answer

Document database

Answer

Graph database

Question 8

A global social media application allows users to post updates and 'like' posts. The application is designed to prioritize availability and partition tolerance over strong consistency. As a result, 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. The application prioritizes availability and partition tolerance, which aligns with the eventual consistency model. In this model, updates (like a 'like' count) are propagated asynchronously across replicas, and while reads may return stale data temporarily, all replicas will converge to the same value over time. This is typical of NoSQL systems like Apache Cassandra or Amazon DynamoDB when configured with eventual consistency.

Answer

Strong consistency

Answer

Consistent prefix

Answer

Bounded staleness

Question 9

Your company has an Azure SQL Database that stores customer orders. You notice that long-running reports are causing blocking on the transactional tables. Which approach would minimize impact on transaction processing while still allowing reporting?

Accepted Answer

Create a read-only replica in Azure SQL Database Hyperscale. Option C is correct because creating a read-only replica offloads reporting queries. Option A is wrong because increasing database throughput does not eliminate blocking. Option B is wrong because READ UNCOMMITTED might cause dirty reads. Option D is wrong because distributing data across databases (sharding) adds complexity and may not solve blocking.

Answer

Use the READ UNCOMMITTED isolation level for reporting queries

Answer

Increase the service tier to Business Critical

Answer

Shard the database by customer region

Question 10

A financial services company is evaluating distributed NoSQL databases for a new application that must remain fully available even during network partitions. The application can tolerate stale reads for some types of queries. Which statement accurately describes the trade-off described by the CAP theorem in this context?

Accepted Answer

When a network partition occurs, a distributed system must choose between providing consistency and providing availability.. The CAP theorem states that during a network partition (P), a distributed system must choose between consistency (C) and availability (A). Since the application requires full availability even during partitions, it must sacrifice strong consistency in favor of eventual consistency, which tolerates stale reads. Option B correctly captures this fundamental trade-off.

Answer

During a network partition, the system can maintain both consistency and availability.

Answer

Partition tolerance is an optional property and can be sacrificed to achieve both consistency and availability.

Answer

Availability guarantees that every read returns the most recent write.

Question 11

A database administrator is explaining to a colleague that a database transaction must ensure that either all operations within it succeed or none of them take effect. Which ACID property is being described?

Accepted Answer

Atomicity. Atomicity ensures that a transaction is treated as a single, indivisible unit of work: either all operations within it are committed successfully, or none are applied. This is the property that guarantees the 'all-or-nothing' behavior described in the question. In Azure SQL Database or SQL Server, atomicity is enforced through the transaction log and the write-ahead logging (WAL) protocol, which records changes before they are written to disk.

Answer

Consistency

Answer

Isolation

Answer

Durability

Question 12

A logistics company stores shipment tracking data. The shipment ID, destination, and weight are stored in a fixed-schema database table. The shipment's route history is stored as a JSON document where each document can have different fields depending on the route events recorded. Which classification of data best describes the route history data?

Accepted Answer

Semi-structured data. The route history data is stored as JSON documents where each document can have different fields depending on the events recorded. This flexibility in schema—where fields vary per document—is the hallmark of semi-structured data. Unlike structured data with a fixed schema, semi-structured data uses tags or markers (like JSON key-value pairs) to organize the data, making it self-describing.

Answer

Structured data

Answer

Unstructured data

Answer

Analytical data

Question 13

A healthcare organization stores patient medical records in a relational database with columns such as PatientID, Name, and DateOfBirth. They also store radiology images as DICOM files in Azure Blob Storage. Which statement correctly classifies these data types?

Accepted Answer

Patient records are structured, and radiology images are unstructured.. Patient records in a relational database with fixed columns like PatientID, Name, and DateOfBirth adhere to a predefined schema, making them structured data. Radiology images stored as DICOM files in Azure Blob Storage have no internal schema or tabular format and are therefore unstructured data. Option C correctly matches these classifications.

Answer

Both patient records and radiology images are structured data.

Answer

Patient records are semi-structured, and radiology images are unstructured.

Answer

Patient records are unstructured, and radiology images are semi-structured.

Question 14

A manufacturing company collects sensor data from equipment on the factory floor. The data is generated continuously and must be processed immediately to detect anomalies and trigger alerts. Which type of data processing workload best describes this scenario?

Accepted Answer

Stream processing. B is correct because the scenario requires continuous data ingestion and immediate processing to detect anomalies and trigger alerts, which is the defining characteristic of stream processing. Technologies like Azure Stream Analytics or Apache Kafka are designed to handle unbounded data streams with low-latency processing, unlike batch processing which operates on static datasets at scheduled intervals.

Answer

Batch processing

Answer

Transactional processing

Answer

Analytical processing

Question 15

A global e-commerce platform uses a combination of relational and NoSQL databases. The order management system requires ACID transactions across multiple tables (Orders, OrderItems, Inventory). The product catalog uses a flexible schema to accommodate varying product attributes and is read-heavy. The session store requires low-latency key-value lookups with eventual consistency. Which of the following pairings of data stores best matches these requirements?

Accepted Answer

Order management: Azure SQL Database - Product catalog: Azure Cosmos DB (NoSQL API) - Session store: Azure Cache for Redis. Option B is correct because Azure SQL Database provides full ACID transaction support across multiple tables, making it ideal for order management. Azure Cosmos DB (NoSQL API) offers a flexible schema and high read throughput for the product catalog. Azure Cache for Redis delivers sub-millisecond key-value lookups with eventual consistency, perfect for session storage.

Answer

Order management: Azure Cosmos DB (NoSQL API) - Product catalog: Azure SQL Database - Session store: Azure Table Storage

Answer

Order management: Azure Table Storage - Product catalog: Azure SQL Database - Session store: Azure Cosmos DB (NoSQL API)

Answer

Order management: Azure Cosmos DB (Table API) - Product catalog: Azure Cache for Redis - Session store: Azure SQL Database