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

Question 1

A research team needs to store thousands of PDF reports that vary in length and structure. The storage solution must allow flexible schema and support access from multiple programming languages via HTTP. Which data storage category best describes these reports?

Accepted Answer

Unstructured data. C is correct because PDF reports with varying length and structure are binary files that do not conform to a predefined data model or schema, which is the definition of unstructured data. Azure Blob Storage or Amazon S3 are typical services for storing such unstructured data, accessed via HTTP REST APIs from any programming language.

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Structured data

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Semi-structured data

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Transactional data

Question 2

A company collects temperature readings from IoT sensors every second. Each reading includes a timestamp, sensor ID, and temperature value. The data is used for real-time monitoring and historical trend analysis. Which type of data is this most likely classified as?

Accepted Answer

Structured data. The data consists of timestamp, sensor ID, and temperature value, each with a defined data type and relationship, fitting a tabular schema (rows and columns) typical of relational databases. This structured format enables efficient querying for real-time monitoring and historical trend analysis using SQL-based systems like Azure SQL Database or Azure Synapse Analytics.

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Semi-structured data

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Unstructured data

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Streaming data

Question 3

A company operates an online store where customers place orders and the system immediately updates inventory and records payments. This workload is best described as:

Accepted Answer

OLTP (Online Transaction Processing). This workload is best described as OLTP because it involves real-time, high-frequency transactions that immediately update inventory and record payments. OLTP systems are designed for concurrent, atomic operations that maintain data integrity, which is exactly what an online store's order processing requires.

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OLAP (Online Analytical Processing)

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Batch processing

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Data warehousing

Question 4

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.

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Stream processing

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Transactional processing

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Interactive query

Question 5

A hospital collects patient vital signs every minute using IoT sensors. Each reading contains a timestamp, patient ID, heart rate, blood pressure, and temperature. This data is ingested continuously for real-time monitoring and alerting. Which type of data workload does this scenario best represent?

Accepted Answer

D. Real-time streaming. This scenario requires continuous ingestion of sensor data with immediate processing for real-time monitoring and alerting. Real-time streaming workloads, such as those handled by Azure Stream Analytics or Apache Kafka, are designed to process unbounded data streams with low latency, making option D correct.

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A. Transactional workload

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B. Analytical workload

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C. Batch processing

Question 6

A startup is building a mobile app that allows users to share short text updates. Each update includes a user ID, timestamp, and message text. The development team expects rapid growth and needs a storage solution that can scale horizontally, handle high write throughput, and provide low-latency reads globally. Which Azure data service is most appropriate?

Accepted Answer

Azure Cosmos DB with a multi-master configuration and partition on user ID.. Azure Cosmos DB with a multi-master configuration is the most appropriate choice because it provides global distribution with multiple write regions, enabling horizontal scaling and low-latency reads and writes worldwide. Partitioning on user ID ensures even data distribution and efficient query performance for the app's high write throughput requirements.

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Azure SQL Database with a single database.

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Azure Blob Storage with append blobs.

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Azure Table Storage with user ID as partition key and timestamp as row key.

Question 7

A company stores customer orders in a relational database. The database enforces rules that every order must have a unique order number and must be linked to an existing customer record. This enforcement of rules to ensure accuracy and consistency is an example of which data concept?

Accepted Answer

Data integrity. Data integrity refers to the enforcement of rules that ensure the accuracy, consistency, and reliability of data throughout its lifecycle. In this scenario, the relational database enforces entity integrity (unique order numbers) and referential integrity (linking orders to existing customer records), which are core mechanisms for maintaining data correctness.

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Data schema

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Data redundancy

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Data latency

Question 8

A social media application allows users to post updates and like posts. After a user clicks the like button, the like count must update immediately and be exactly the same for all users viewing the post. Which data consistency model best fits this requirement?

Accepted Answer

Strong consistency. Strong consistency ensures that after a write operation (like clicking the like button) completes, any subsequent read operation returns the most recent write. This guarantees that all users viewing the post see the exact same, up-to-date like count immediately. This is required for the social media scenario where the like count must be identical for all viewers without any delay.

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Eventual consistency

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Session consistency

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Bounded staleness consistency

Question 9

A company stores customer names and addresses in a fixed-format file where each record has the same fields in the same order. This type of data is best described as:

Accepted Answer

Structured data. A fixed-format file where each record has the same fields in the same order is a classic example of structured data. Structured data conforms to a rigid schema, such as a table with defined columns and data types, making it easily searchable and processable by relational database systems like Azure SQL Database. The consistent field order and fixed format allow for direct parsing without interpretation.

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Semi-structured data

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Unstructured data

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Streaming data

Question 10

A healthcare application stores patient medical history in a relational database. The system must ensure that after a transaction updates multiple records (e.g., diagnosis and medication), all changes are saved or none are saved. This property is best described as:

Accepted Answer

Atomicity. Atomicity ensures that a transaction is treated as a single, indivisible unit of work. In the context of a relational database storing patient medical history, if a transaction updates both the diagnosis and medication records, atomicity guarantees that either both updates are committed or both are rolled back, preventing partial updates that could leave the data in an inconsistent state.

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Consistency

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Durability

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Isolation

Question 11

A marketing company collects data from social media feeds including text posts, images, and videos. The data arrives in various formats with no fixed structure or schema. This type of data is best described as:

Accepted Answer

C) Unstructured data. Unstructured data lacks a predefined data model or schema, making it ideal for storing text posts, images, and videos that arrive in varied formats. Unlike structured or semi-structured data, unstructured data cannot be easily organized into rows and columns or parsed with tags, which is why option C is correct for this scenario.

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A) Structured data

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B) Semi-structured data

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D) Relational data

Question 12

A banking system processes a money transfer between two accounts. The system is designed so that after the transaction is committed, the results are permanently saved and survive any subsequent system failure, such as a power outage. Which ACID property ensures this behavior?

Accepted Answer

Durability. Durability ensures that once a transaction is committed, its changes are permanently stored and survive system failures, such as power outages or crashes. In this banking scenario, the money transfer results are written to non-volatile storage (e.g., disk) via a write-ahead log, guaranteeing that the committed state is recoverable even after a restart.

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Atomicity

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Consistency

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Isolation

Question 13

A retail company collects data from online transactions including order ID, customer details, product IDs, quantities, and timestamps. The data is stored in a relational database and used for order processing and inventory management. Which characteristic of this data makes it structured?

Accepted Answer

It is stored in rows and columns with a predefined schema.. Option A is correct because structured data is defined by a fixed schema where each entity (e.g., orders) is stored in rows and columns with predefined data types (e.g., INT for order ID, VARCHAR for customer details). This relational model enforces consistency and enables efficient querying via SQL for order processing and inventory management.

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It is stored as key-value pairs.

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It is stored in JSON format with variable fields.

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It is stored in unstructured text files.

Question 14

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.

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Consistency

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Isolation

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Durability

Question 15

A company stores customer data in a relational database. The database design includes a rule that every order must be associated with a valid customer ID that exists in the Customers table. This rule is an example of which data concept?

Accepted Answer

Referential integrity. Referential integrity ensures that relationships between tables remain consistent. In a relational database, a foreign key constraint enforces that every order's customer ID must match an existing customer ID in the Customers table, preventing orphaned records. This rule directly implements referential integrity as defined by the SQL standard (e.g., via FOREIGN KEY constraints).

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Data normalization

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Entity integrity

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Data consistency