DP-900 Practice Questions

The Archive tier is designed for long-term data archival. It provides the lowest storage cost but has higher data retrieval costs and latency compared to the Hot and Cool tiers. The retrieval time of several hours is acceptable for the audit requirement, making the Archive tier the most cost-effective solution for this long-term, infrequent-access scenario.

A view is a stored query that acts as a virtual table. It does not store data itself but presents data from one or more underlying tables. Views are often used to simplify complex queries, provide a layer of security by restricting access to certain columns or rows, and present data in a more user-friendly format.

This statement is false. Azure Synapse Analytics is a limitless analytics service that brings together enterprise data warehousing and big data analytics. It provides a unified experience to ingest, prepare, manage, and serve data for immediate business intelligence and machine learning needs. It includes capabilities like serverless and dedicated SQL pools (for data warehousing), Apache Spark pools (for big data), and integration with data lakes.

A key characteristic of unstructured data is its lack of a predefined schema. It can be in any format and doesn't fit neatly into rows and columns.

Media files like audio, video, and images are classic examples of unstructured data because their internal structure is not defined in a way that a traditional database can easily parse and query.

The Azure Cosmos DB for MongoDB is a wire-protocol compatible implementation of the MongoDB API. This allows existing MongoDB applications, drivers, and tools to interact with Cosmos DB with minimal or no code changes. The application simply needs to change its connection string to point to the Cosmos DB endpoint.

This is the optimal solution. Azure Cosmos DB is excellent for storing and querying structured (demographics) and semi-structured (text notes) data in a single document per patient, offering fast retrieval. Azure Blob Storage is the most cost-effective and performant service for storing large binary files like medical images (unstructured data). The Cosmos DB record can simply store a URI pointing to the image in Blob Storage.

DAX time intelligence functions, such as SAMEPERIODLASTYEAR, PREVIOUSMONTH, or TOTALYTD, are specifically designed to simplify and perform common time-based comparisons and calculations. Using these functions is the standard and most efficient way to compare data across different time periods in Power BI.

Parquet is a columnar storage format that is highly optimized for analytical workloads. It offers excellent compression, which reduces storage costs and improves query performance. Crucially, it supports schema evolution, allowing you to add, remove, or modify columns over time without breaking existing data pipelines. It is the preferred format for large-scale analytics in services like Azure Synapse and Databricks.

This statement is false. In OLTP systems, data is typically normalized (e.g., to Third Normal Form) to reduce data redundancy, prevent data modification anomalies, and ensure data integrity for frequent write operations (inserts, updates, deletes). Denormalization is a technique used in Online Analytical Processing (OLAP) systems or data warehouses to optimize read performance for complex queries by intentionally adding redundant data.

Azure Cosmos DB is a globally distributed, multi-model database service designed for low-latency (single-digit millisecond) reads and writes at any scale. Its key feature is turnkey global distribution, which allows you to replicate data to any Azure region and configure any region as a writable endpoint. This makes it the ideal choice for applications with a global user base requiring high availability and performance.