DP-900 Describe core data concepts Practice Test 5 — 15 Questions

Question 1

A retail company processes historical sales data in a nightly batch job that loads aggregated reports into a data warehouse. Additionally, the company analyzes live customer interactions from their website to provide real-time product recommendations. Which pair of terms correctly describes these two data processing approaches?

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

Accepted Answer

Batch processing and streaming processing. The nightly batch job that loads aggregated reports into a data warehouse is a classic example of batch processing, where data is processed in large, scheduled chunks. The real-time analysis of live customer interactions for product recommendations is streaming processing, which handles data continuously as it arrives. Option B correctly pairs these two distinct processing paradigms.

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OLTP and OLAP

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Structured data and unstructured data

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Relational and NoSQL

Question 2

A company stores customer names and addresses in a relational table, product descriptions as JSON files, and product images as JPEG files. Which of the following correctly classifies these data types from most structured to least structured?

Accepted Answer

Structured (customer table), Semi-structured (JSON), Unstructured (JPEG). A is correct because structured data (customer table) has a fixed schema with rows and columns, semi-structured data (JSON) uses tags or key-value pairs without a rigid schema, and unstructured data (JPEG) has no predefined structure. The question tests the standard classification hierarchy from most to least structured.

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Structured (customer table), Unstructured (JSON), Semi-structured (JPEG)

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Semi-structured (customer table), Structured (JSON), Unstructured (JPEG)

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Unstructured (customer table), Structured (JSON), Semi-structured (JPEG)

Question 3

An e-commerce application processes customer orders. When an order is placed, the system must decrement the inventory count and process the payment. The application ensures that either both operations complete successfully or both are rolled back if any error occurs. Which database property does this guarantee?

Accepted Answer

Atomicity. Atomicity ensures that a transaction is treated as a single, indivisible unit of work: either all operations within it (decrement inventory and process payment) complete successfully, or none are applied. If any part fails, the database rolls back all changes, maintaining the 'all-or-nothing' guarantee. This is the core property described in the scenario.

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Consistency

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Isolation

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Durability

Question 4

A retail company operates an online store. When a customer places an order, the system immediately updates inventory and payment records. Separately, the company's business analysts run weekly reports that aggregate sales data to identify trends. Which two terms correctly describe these workloads?

Accepted Answer

Batch processing and real-time processing. Option A is correct because the order-placement workload that immediately updates inventory and payment records is real-time (transactional) processing, while the weekly aggregate sales reports run on a schedule over accumulated data, which is batch processing. Option B is correct because the immediate, row-level insert/update of inventory and payment records is classic OLTP (Online Transaction Processing), whereas the weekly aggregation of sales data for trend analysis is classic OLAP (Online Analytical Processing). Option C is not correct because the scenario describes operational and analytical processing patterns, not a contrast between structured and unstructured data formats. Option D is not correct because data ingestion and data transformation are pipeline stages (extract/load and convert/clean), not the workload categories being contrasted here.

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Structured and Unstructured data

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Data ingestion and data transformation

Question 5

A company is evaluating Azure database services for two different workloads. Workload A processes high-volume, low-latency transactions such as order entry and payment processing, where each transaction updates a few rows. Workload B involves running complex aggregations on terabytes of historical sales data to generate monthly business intelligence reports. Which Azure service is best suited for each workload?

Accepted Answer

B. Workload A: Azure Cosmos DB; Workload B: Azure Synapse Analytics. Workload A requires a low-latency, high-throughput transactional database capable of handling many small, row-level updates. Azure Cosmos DB is a NoSQL database designed for single-digit millisecond latency and horizontal scaling, making it ideal for order entry and payment processing. Workload B involves complex aggregations on terabytes of historical data, which is best handled by Azure Synapse Analytics, a distributed analytics service that uses massively parallel processing (MPP) to run large-scale queries efficiently.

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A. Workload A: Azure SQL Database; Workload B: Azure Cosmos DB

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C. Workload A: Azure Synapse Analytics; Workload B: Azure SQL Database

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D. Workload A: Azure Cosmos DB; Workload B: Azure Cosmos DB

Question 6

A company stores customer records in a relational database table with fixed columns (CustomerID, Name, Email). They also store product reviews as JSON documents that may contain varying fields such as Rating, Comment, and optional Tags. Additionally, they store product images as JPEG files. Which of the following correctly orders these data types from most structured to least structured?

Accepted Answer

Relational table, JSON documents, image files. Relational tables enforce a fixed schema with predefined columns and data types, making them the most structured. JSON documents have a flexible schema where fields like Tags are optional, placing them in the middle. Image files are binary blobs with no inherent structure, making them the least structured. Option B correctly orders these from most structured (relational table) to least structured (image files).

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JSON documents, relational table, image files

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Image files, relational table, JSON documents

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Relational table, image files, JSON documents

Question 7

A ride-sharing company processes trip requests from customers. Each trip is recorded as a single transaction that updates the driver's status, calculates the fare, and logs the ride. At the end of each month, the company runs reports that aggregate millions of trips to determine average wait times and revenue per driver. Which pair of terms best describes these two distinct workloads?

Accepted Answer

OLTP and OLAP. The first workload (trip request processing) is a classic OLTP (Online Transaction Processing) system because each trip is a single, atomic transaction that updates driver status, calculates fare, and logs the ride in real time. The second workload (monthly aggregation reports) is OLAP (Online Analytical Processing) because it queries millions of historical trip records to compute averages and revenue summaries. These two patterns have fundamentally different data storage and query optimization requirements, making OLTP and OLAP the correct pair.

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Batch processing and stream processing

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ETL and ELT

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Relational and non-relational

Question 8

A bank processes online fund transfers. Each transaction must ensure that either both the debit from the sender's account and the credit to the receiver's account occur, or if any part fails, the entire transaction is rolled back. Which ACID property does this guarantee?

Accepted Answer

Atomicity. Atomicity ensures that a transaction is treated as a single, indivisible unit of work. In this fund transfer scenario, atomicity guarantees that both the debit and credit operations either complete successfully together or are fully rolled back if any part fails, preventing partial updates that could leave the system in an inconsistent state.

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Consistency

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Isolation

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Durability

Question 9

A data analyst receives a dataset containing customer order details stored in a CSV file, a JSON file with product reviews, and a folder of JPEG images of products. Which of the following correctly categorizes these data types from most structured to least structured?

Accepted Answer

CSV → JSON → JPEG. CSV files are highly structured with rows and columns defined by a schema, making them the most structured. JSON files are semi-structured, using key-value pairs and nested objects that allow flexibility but lack a fixed schema. JPEG images are unstructured binary data with no inherent schema, so the correct order from most to least structured is CSV → JSON → JPEG, making option C correct.

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CSV → JPEG → JSON

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JSON → CSV → JPEG

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JPEG → JSON → CSV

Question 10

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.

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Consistency

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Isolation

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Durability

Question 11

In a banking application, a transaction transfers $100 from Account A to Account B. The system deducts $100 from Account A successfully, but due to a network error, the credit to Account B fails. The application rolls back the deduction from Account A, ensuring that neither account is affected. Which ACID property is being enforced?

Accepted Answer

Atomicity. Atomicity ensures that a transaction is treated as a single, indivisible unit of work. In this scenario, the deduction from Account A and the credit to Account B must both succeed or both fail entirely. When the credit to Account B fails, the system rolls back the deduction from Account A, preserving the all-or-nothing nature of the transaction. This is the core behavior of atomicity in ACID-compliant database systems like Azure SQL Database or SQL Server.

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Consistency

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Isolation

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Durability

Question 12

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.

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Strong consistency

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Consistent prefix

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Bounded staleness

Question 13

A healthcare company stores patient records in a relational database with fixed columns (PatientID, Name, DOB, BloodType). Medical images such as X-rays are stored as DICOM files. Clinical notes are stored as free-text documents. Which of the following correctly classifies these data types from most structured to least structured?

Accepted Answer

Patient records (structured), DICOM files (semi-structured), Clinical notes (unstructured). Patient records in a fixed-column relational database are structured data because they conform to a rigid schema with defined data types. DICOM files are semi-structured because they contain a structured header with metadata tags (e.g., patient ID, study date) alongside an unstructured binary image payload. Clinical notes as free-text documents are unstructured because they lack a predefined schema or organization, making them difficult to query without natural language processing.

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Patient records (structured), DICOM files (structured), Clinical notes (unstructured)

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Patient records (semi-structured), DICOM files (unstructured), Clinical notes (structured)

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Patient records (unstructured), DICOM files (semi-structured), Clinical notes (structured)

Question 14

A healthcare organization is planning a data analytics platform. They will ingest data from various sources: structured patient records from a relational database, semi-structured JSON logs from medical devices, and unstructured physician notes as plain text files. Which characteristic of big data describes the different formats of data being ingested?

Accepted Answer

Variety. The question describes data in three distinct formats: structured (relational database), semi-structured (JSON logs), and unstructured (plain text). In big data terminology, 'Variety' specifically refers to the different types and formats of data being processed. This is a core concept in the 4 V's of big data, where Variety captures the heterogeneity of data sources and structures.

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Volume

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Velocity

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Veracity

Question 15

A retail chain collects sales data from all its stores at the end of each business day by exporting CSV files from each store's database. The data is then combined and analyzed to generate daily sales reports. Which type of data processing does this describe?

Accepted Answer

Batch processing. This describes batch processing because sales data is collected from each store at the end of the business day, exported as CSV files, and then combined and analyzed in a scheduled, non-continuous manner. Batch processing is ideal for large volumes of data that are processed at periodic intervals, such as daily sales reports, rather than requiring immediate action.

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Real-time processing

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Stream processing

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Interactive query