DP-900 - Describe Core Data Concepts (30% of the exam) - Section 1.2

Identify options for data storage including file stores, databases, and data lakes.

Describe the characteristics of file stores, relational databases, non-relational databases, data lakes, and data warehouses as distinct storage options. Choose the appropriate store based on whether data is structured, the access pattern is transactional or analytical, and whether schema flexibility is needed.

file storesrelational databasesnon-relational databasesdata lakesdata warehouses

Practice question for this objective

Free sampleDescribe Core Data Conceptsmedium

Which statement correctly contrasts a data warehouse with a data lake in an analytical architecture?

AA data warehouse stores raw file-based data as-is, while a data lake enforces a relational SQL schema
BA data warehouse uses a relational schema optimised for read queries, while a data lake holds raw file-based data Correct
CA data warehouse is built for high-volume write transactions, while a data lake serves reporting queries only
DA data warehouse holds only pre-aggregated measures, while a data lake holds the relational fact and dimension tables

A data warehouse is a read-optimised relational store; a data lake holds large volumes of file-based data. Data warehouses store data in a relational schema optimised for read operations to support reporting and visualisation, while data lakes collect large volumes of file-based data for analysis.

Why A is wrong: This reverses the two stores: the lake collects large volumes of file-based data, while the warehouse is the relational, schema-based store.

Why B is correct: Correct. Data warehouses store data in a relational schema optimised for read operations to support reporting and visualisation, while data lakes collect large volumes of file-based data for analysis.

Why C is wrong: High-volume writes describe OLTP, not a warehouse; the warehouse is optimised for read queries that support reporting and visualisation.

Why D is wrong: Pre-aggregated measures belong to the OLAP semantic model, and fact and dimension tables sit in the warehouse rather than the lake.

See more DP-900 practice questions, answers explained.

Exam traps in Describe Core Data Concepts

Answers that look right on this material and are not. Each one is a distractor from a different question in the DP-900 bank for this domain.

A transactional workload, because the sales data originates from live point-of-sale systems
Why it is wrong: Although the source is transactional, the workload described stores historical snapshots optimised for reading and reporting, which is analytical rather than transactional.
It enforces ACID semantics on each small unit of work
Why it is wrong: Per-transaction ACID enforcement is a transactional (OLTP) trait.
A graph database that stores entities as nodes with links that define relationships between them
Why it is wrong: A graph database models relationships as links between nodes, but it does not provide the normalised table-and-primary-key structure the retailer wants for eliminating duplicate customer values.

Examworthy is not affiliated with or endorsed by Microsoft. Original, blueprint-aligned practice material only.