DP-900 Describe core data concepts — 20 Questions

Question 1

A hospital system stores patient medical records. Each record includes structured data like patient ID, name, date of birth, and also includes unstructured data like doctor's notes and X-ray images. Which type of data is the doctor's notes?

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

Accepted Answer

C. Unstructured data. Doctor's notes are unstructured data because they consist of free-form text that does not follow a predefined data model or schema. Unlike structured data (e.g., patient ID, name) which fits neatly into rows and columns, doctor's notes lack a fixed format and cannot be easily queried using traditional relational database tools without additional processing.

Answer

A. Structured data

Answer

B. Semi-structured data

Answer

D. Relational data

Question 2

A manufacturing company uses IoT sensors to monitor machine temperature. The data is analyzed immediately to trigger alerts if temperature exceeds a threshold. The same data is also stored and later analyzed to identify long-term trends. Which two terms best describe these data processing approaches?

Accepted Answer

Real-time processing for alerts, batch processing for trend analysis. Only Option A is correct. In this scenario, alerts require immediate analysis, which is achieved by real-time processing (or stream processing). For long-term trend analysis, data is stored and processed in bulk using batch processing. Option B incorrectly pairs stream processing with transactional processing: transactional processing (OLTP) is designed for transaction-oriented workloads, not analytical trend analysis. The correct approach for trend analysis is batch processing, not transactional processing. Options C and D reverse the pairings or use inappropriate terms (OLAP/OLTP) for the described workloads.

Answer

Stream processing for alerts, transactional processing for trend analysis

Answer

Batch processing for alerts, real-time processing for trend analysis

Answer

OLAP for alerts, OLTP for trend analysis

Question 3

A car manufacturing company has two data processing systems: one system processes real-time sensor data from assembly lines to immediately detect equipment failures, and another system processes historical production records to generate monthly efficiency reports. Which two types of data processing workloads best describe these systems?

Accepted Answer

Stream processing and batch processing. Stream processing (option A) handles real-time sensor data from the assembly line to detect equipment failures immediately, while batch processing (option A) is ideal for processing historical production records on a scheduled basis to generate monthly efficiency reports. Transactional processing (option D) refers to OLTP workloads that process business transactions, not real-time sensor streams, so it is not a correct description for the first system. The correct answer is A only.

Answer

OLTP and OLAP

Answer

Online processing and offline processing

Answer

Transactional processing and analytical processing

Question 4

A global e-commerce platform uses a distributed database for its shopping cart service. The platform must be highly available and continue to accept writes even if network partitions occur between data centers. The business accepts that during a partition, users might see slightly outdated inventory counts, but the service must remain operational. According to the CAP theorem, which two properties is this system prioritizing?

Accepted Answer

Availability and Partition Tolerance. According to the CAP theorem, during a network partition, a distributed system must choose between consistency and availability. This system is designed to remain available and accept writes even during partitions, accepting that users may see slightly outdated inventory (inconsistent data). Therefore, it prioritizes Availability and Partition Tolerance (AP). Option C (Consistency and Availability) is not possible during a partition. The correct answer is B only.

Answer

Consistency and Partition Tolerance

Answer

Consistency and Availability

Answer

Durability and Partition Tolerance

Question 5

A globally distributed online auction platform uses a replicated database system across multiple Azure regions. The system must continue accepting bids (writes) even if a network partition occurs between regions, because auctions cannot be interrupted. The business decides that during a partition, some users might see slightly outdated item prices (read inconsistency) but all bids must be recorded. According to the CAP theorem, which two properties is this system prioritizing?

Accepted Answer

Availability (A) and Partition Tolerance (P). The CAP theorem defines three properties: Consistency (C), Availability (A), and Partition Tolerance (P). The system continues accepting bids during network partitions, prioritizing Availability (every request receives a response) and Partition Tolerance (system operates despite network splits). Option A (Availability and Partition Tolerance) directly describes this AP trade-off. Option D (Durability and Availability) is incorrect because Durability is not a CAP property; it belongs to ACID. The question specifically asks for CAP properties, so only A is correct.

Answer

Consistency (C) and Partition Tolerance (P)

Answer

Consistency (C) and Availability (A)

Answer

Durability and Availability

Question 6

Which THREE factors should you consider when choosing between Azure SQL Database and Azure Cosmos DB for a new application?

Accepted Answer

Need for multi-region writes. Option A (Need for multi-region writes) is correct because Azure Cosmos DB natively supports multi-region writes with multi-master replication across any Azure region, whereas Azure SQL Database requires a more complex setup (such as active geo-replication with manual failover or auto-failover groups) and does not offer true multi-master write capability. Option B (Schema flexibility requirements) is correct because Cosmos DB is schema-agnostic and stores JSON documents without a predefined schema, while Azure SQL Database enforces a rigid relational schema with tables, columns, and data types defined up front. Option C (Transaction consistency requirements) is correct because Cosmos DB offers five well-defined consistency levels (strong, bounded staleness, session, consistent prefix, eventual) that let you trade off consistency versus latency and availability, whereas Azure SQL Database provides strong ACID consistency by default with no tunable consistency spectrum. Option D (Support for JSON data) is not a distinguishing factor because both services support JSON — Azure SQL Database has native JSON functions (JSON_VALUE, FOR JSON, OPENJSON) and Cosmos DB stores JSON natively — so it does not help choose between them. Option E (Support for T-SQL queries) is not a distinguishing factor either, since Azure SQL Database uses T-SQL as its primary query language and Cosmos DB's SQL API also supports a SQL-like query syntax, so both can satisfy T-SQL-style querying needs.

Answer

Support for JSON data

Answer

Support for T-SQL queries

Question 7

A company needs to store relational data that requires frequent updates and supports complex joins. They also need to scale out reads by using read replicas. Which Azure service should they choose?

Accepted Answer

Azure Database for MySQL. Both Azure Database for MySQL and Azure SQL Database are fully managed relational database services that support frequent updates, complex joins via SQL, and read replicas for scaling out read-heavy workloads. Azure Database for MySQL offers up to five read replicas; Azure SQL Database offers up to four active geo-replicas that can be used for read-only queries. Azure Cosmos DB is a NoSQL database and does not support complex joins natively. Azure Table Storage is a NoSQL key-value store and does not support relational operations.

Answer

Azure Cosmos DB

Answer

Azure Table Storage

Question 8

A healthcare organization must store patient records with strict compliance requirements. They need to classify data as public, internal, or confidential, and apply encryption and access policies accordingly. Which Microsoft Purview feature should they use?

Accepted Answer

Microsoft Purview Data Map. Microsoft Purview Data Map is the foundational component of Microsoft Purview that automatically discovers, scans, and classifies data across hybrid and multi-cloud environments. This automated data classification (e.g., public, internal, confidential) provides the essential metadata that other Microsoft Purview features, such as Information Protection, leverage to apply sensitivity labels, encryption, and access policies, thereby meeting strict compliance requirements for patient records.

Answer

Azure Policy

Answer

Microsoft Defender for Cloud

Answer

Azure Information Protection

Question 9

Your team is migrating on-premises SQL Server databases to Azure. They need to minimize application changes and support both OLTP and reporting workloads. Which Azure data service supports hybrid transactional and analytical processing (HTAP)?

Accepted Answer

Azure SQL Database with Hyperscale. Azure SQL Database with Hyperscale supports hybrid transactional and analytical processing (HTAP) by leveraging built-in columnstore indexes and near-instantaneous snapshot isolation. This allows the same database to efficiently handle high-volume OLTP transactions while simultaneously running complex analytical queries on up-to-date data. While Azure SQL Database offers high compatibility with SQL Server, the extent of application changes required can vary depending on the specific features used in the on-premises database.

Answer

Azure Analysis Services

Answer

Azure SQL Managed Instance

Answer

Azure Data Factory

Question 10

Which TWO of the following Azure services are categorized as Platform as a Service (PaaS) for data storage?

Accepted Answer

Azure Cosmos DB. Azure Cosmos DB (A) is a fully managed, globally distributed multi-model database service, so Microsoft handles the underlying infrastructure, OS patching, and scaling, which is the defining characteristic of PaaS. Azure SQL Database (D) is likewise a fully managed relational database engine delivered as a service, where the platform manages high availability, backups, and upgrades, making it PaaS rather than IaaS. Azure Synapse Analytics dedicated SQL pool (B) is a data warehousing/analytics workload rather than a general PaaS data-storage service, and Azure Data Lake Storage Gen2 (C) is a storage-layer capability built on Blob Storage rather than a PaaS database service. Azure Virtual Machines with SQL Server (E) is Infrastructure as a Service because you manage the VM's operating system and SQL Server instance yourself.

Answer

Azure Synapse Analytics dedicated SQL pool

Answer

Azure Data Lake Storage Gen2

Answer

Azure Virtual Machines with SQL Server

Question 11

The exhibit shows an ARM template snippet for deploying an Azure storage account. What is the redundancy level of the storage account?

Accepted Answer

Locally redundant storage (LRS). The exhibit shows the storage account resource with a 'sku' property set to 'Standard_LRS'. The 'name' value 'Standard_LRS' explicitly specifies Locally redundant storage (LRS), which replicates data three times within a single datacenter. Other redundancy levels like GRS or ZRS would require a different SKU name such as 'Standard_GRS' or 'Standard_ZRS'.

Answer

Read-access geo-redundant storage (RA-GRS)

Answer

Zone-redundant storage (ZRS)

Answer

Geo-redundant storage (GRS)

Question 12

A company uses Azure Data Lake Storage Gen2 for a data lake. They need to ensure that only authorized users can access files and that access is audited. Which two Azure services should they combine? (Choose two options that together form the solution.)

Accepted Answer

Azure RBAC. Azure RBAC (Option C) is correct because it provides the authorization layer for ADLS Gen2: role assignments such as Storage Blob Data Reader, Storage Blob Data Contributor, and Storage Blob Data Owner scope access to files and directories, and can be applied at the container or directory level via ACLs, ensuring only authorized users can access data. Azure Monitor (Option D) is correct because it collects and retains diagnostic logs and metrics for ADLS Gen2, including the storage read/write/delete and authentication logs sent to a Log Analytics workspace, storage account, or Event Hub, which is what enables auditing of who accessed which files. Azure Policy (Option A) is not the right fit because it enforces governance and compliance rules on resources (for example, requiring diagnostic settings or allowed SKUs) rather than granting or auditing data-plane file access. Azure Key Vault (Option B) is for storing and managing secrets, keys, and certificates, not for authorizing or auditing data-lake file access. Microsoft Entra ID (Option E) provides identity and authentication, but the question asks for the services that together enforce authorization and auditing, which are RBAC and Azure Monitor.

Answer

Azure Policy

Answer

Azure Key Vault

Answer

Microsoft Entra ID

Question 13

You are analyzing the results of a KQL query in Azure Data Explorer. What does this query return?

Accepted Answer

Top 5 states with highest total property damage from floods. The KQL query uses the 'summarize' operator to aggregate total property damage by state, then applies 'top 5 by' to return the five states with the highest total property damage from flood events. The 'where' clause filters for flood events, and the 'project' operator selects only the state and damage columns, confirming that the result is the top 5 states by total property damage.

Answer

Total damage per event type

Answer

All states with flood events sorted by damage

Answer

Top 5 flood events with highest damage

Question 14

You are reviewing an ARM template for an Azure SQL Database deployment. What is the maximum size of the database?

Accepted Answer

5 GB. The explanation incorrectly states that the maximum size for the Basic tier of Azure SQL Database is 5 GB. According to current Microsoft documentation, the actual maximum data size for the Basic tier (DTU-based) is 2 GB. Furthermore, 5 GB is not a recognized maximum database size for any standard Azure SQL Database service tier. The question itself is ambiguous without specifying a service tier, as maximum sizes vary significantly across different tiers (e.g., Basic: 2 GB, Hyperscale: 100 TB). Therefore, the question as presented cannot be answered correctly with the given options.

Answer

50 GB

Answer

5 MB

Answer

500 GB

Question 15

Which THREE are valid Azure data storage services that support semi-structured data?

Accepted Answer

Azure Cosmos DB. Azure Cosmos DB (A) is correct because it natively stores JSON documents and supports schema-flexible, semi-structured data through APIs such as SQL, MongoDB, and Gremlin. Azure Table Storage (C) is correct because it stores entities as key-value property sets with flexible schemas, which is a classic semi-structured NoSQL model. Azure Blob Storage (D) is correct because it can hold semi-structured formats like JSON, XML, Avro, and Parquet as objects without requiring a fixed relational schema. Azure Data Lake Storage (E) is correct because it is built on Blob Storage and is designed for storing semi-structured and unstructured data such as JSON, CSV, and Parquet for analytics workloads. Azure SQL Database (B) is not marked correct because it is a relational database service that primarily enforces a fixed schema for structured data, even though it has some JSON functions.

Answer

Azure SQL Database

Question 16

Refer to the exhibit. You are analyzing storm event data in Azure Data Explorer. The KQL query returns the top 5 event types by count in Texas. However, the results show event types with very low counts (e.g., 'Volcanic Ash' with 2 events). What is the most likely reason for this?

Accepted Answer

The state filter is case-sensitive and the actual state value differs.. Azure Data Explorer (ADX) is case-sensitive by default in string comparisons. The 'where' clause filters on the 'state' column, and if the actual value in the data is 'texas' (lowercase) or 'TEXAS' (uppercase), the filter 'state == "Texas"' will not match any rows. This causes the query to return results from all states, including those with very low event counts like 'Volcanic Ash' from other regions.

Answer

The query has a syntax error.

Answer

The 'take' operator limits the number of events, not the number of types.

Answer

The 'summarize' operator cannot be used with 'where'.

Question 17

Refer to the exhibit. You create an Azure Policy to deny virtual machines that are not using approved SKUs. After assigning the policy to a subscription, a user tries to create a VM with SKU 'Standard_DS2_v2' and the creation is allowed. What is the most likely reason?

Accepted Answer

The alias 'Microsoft.Compute/virtualMachines/sku.name' is incorrect; the correct alias is 'Microsoft.Compute/virtualMachines/sku'.. The alias 'Microsoft.Compute/virtualMachines/sku.name' is invalid. In Azure Policy, the alias for the SKU property of a virtual machine is 'Microsoft.Compute/virtualMachines/sku'. The 'name' child property is not part of the alias path. Using an incorrect alias means the policy rule never evaluates the intended property, so the deny effect never triggers, allowing any SKU to be created.

Answer

The policy is not assigned to the resource group where the VM is created.

Answer

The field type 'Microsoft.Compute/virtualMachines' is incorrect.

Answer

The policy rule does not specify a deny effect.

Question 18

Which TWO of the following are characteristics of structured data?

Accepted Answer

Data is organized in rows and columns. Structured data is defined by its organization into rows and columns, typically within a relational database or spreadsheet, where each column represents a specific attribute and each row a record. This tabular format enables efficient querying, sorting, and aggregation using SQL. Option B correctly identifies this core characteristic.

Answer

Data uses tags or markers to separate elements

Answer

Data is stored in Azure Cosmos DB

Answer

Data has no predefined schema

Question 19

Which THREE of the following are benefits of using Azure Data Lake Storage Gen2?

Accepted Answer

Cost-effective for storing petabytes of data. Option A is correct because Azure Data Lake Storage Gen2 is built on Blob Storage and is designed to be cost-effective for storing petabytes of data, offering tiered storage and low-cost capacity for massive datasets. Option B is correct because ADLS Gen2 supports POSIX-compliant access control lists (ACLs), enabling fine-grained, file- and directory-level permissions that are essential for big data analytics workloads. Option E is correct because ADLS Gen2 provides a hierarchical namespace, which organizes objects into directories and enables efficient directory-level operations such as atomic renames and deletes. Option C is incorrect because ADLS Gen2 is not a NoSQL document store; that role belongs to Azure Cosmos DB. Option D is incorrect because ADLS Gen2 is a storage service and does not include an integrated data transformation engine; transformation is handled by separate services such as Azure Data Factory, Azure Databricks, or Azure Synapse Analytics.

Answer

Built-in NoSQL document store

Answer

Integrated data transformation engine

Question 20

Your organization is migrating its on-premises SQL Server databases to Azure. The databases include a mix of operational (OLTP) and analytical (OLAP) workloads. For the OLTP databases, you need high availability and automated failover to a secondary region. For the OLAP databases, you need to support large-scale analytic queries with columnstore indexes and the ability to pause compute to save costs. Which Azure SQL deployment options should you choose for each workload type?

Accepted Answer

Azure SQL Database (geo-replication) for OLTP; Azure Synapse Analytics (dedicated SQL pool) for OLAP. Azure SQL Database with active geo-replication provides high availability and automated failover to a secondary region for OLTP workloads, while Azure Synapse Analytics (dedicated SQL pool) supports large-scale analytic queries with columnstore indexes and allows pausing compute to save costs, meeting the OLAP requirements.

Answer

Azure SQL Managed Instance for both

Answer

SQL Server on Azure Virtual Machines for both

Answer

Azure SQL Database Hyperscale for OLTP; Azure SQL Database Serverless for OLAP