Identify and Connect to Data Sources or a Shared Semantic Model (PL-300 Exam Prep) – The Data Community

What percentage of the PL-300 exam is represented by the 'Prepare the data' domain?

$$25\text{--}30\%$$

Which Power BI connectivity mode loads data into an in-memory dataset and provides the fastest performance?

Import mode

When should an analyst choose Import mode?

When data size is manageable, full modeling flexibility is needed, and performance is the top priority.

Where is data stored when using DirectQuery mode in Power BI?

Data remains in the source system, with minimal data stored in Power BI.

What primary factor determines reporting performance when using DirectQuery mode?

The performance of the underlying source system.

In what business scenarios is DirectQuery mode recommended over Import mode?

When data is extremely large, must remain in the source system, or requires near-real-time reporting.

What mechanism does DirectQuery depend heavily on for Power Query transformations?

Query folding

What was a shared semantic model formerly called in Power BI?

A dataset (or Power BI dataset)

Which two source types are utilized when connecting via a Live Connection?

Shared semantic models (Power BI datasets) or Analysis Services.

Where is data modeling conducted when using a Live Connection?

In the source dataset or Analysis Services (no local model is created).

What kind of DAX measures can an analyst create when using a Live Connection to a shared semantic model?

Report-level measures only

Which modeling actions are prohibited when connected via a Live Connection to a shared semantic model?

Modifying relationships, creating calculated tables, and creating calculated columns.

How is Row-level security (RLS) handled when connecting via a Live Connection?

It is inherited from the source.

What are the four primary benefits of using shared semantic models?

Consistent metrics and definitions, reduced duplication of logic, centralized governance and security, and faster report development.

Which connection mode should be selected for a large transactional database updated every minute?

DirectQuery

Which solution should be selected when multiple teams need consistent KPIs across reports?

A shared semantic model (Live connection)

Which connector should be used for files stored in SharePoint that are updated weekly?

SharePoint Folder connector

What four common enterprise authentication types are identified for Power BI data sources?

Windows authentication, Database authentication, Microsoft Entra ID (Azure AD), and OAuth.

What ultimately determines an analyst's ability to connect to a data source besides Power BI settings?

Permissions at the source

How do data refresh requirements differ between Import mode and DirectQuery mode?

Import mode requires scheduled or manual dataset refreshes, whereas DirectQuery requires no dataset refresh because queries run live.

How does Power Query transformation support differ among Import, DirectQuery, and Live Connection modes?

Import mode fully supports transformations, DirectQuery has limited support dependent on query folding, and Live Connection does not support transformations.

What four file-based data sources are highlighted for Power BI?

Excel workbooks, CSV and text files, XML and JSON files, and PDF files (structured tables).

What three data sources are listed under the Power Platform and Power BI category?

Power BI datasets (shared semantic models), Dataflows, and Datamarts.

What are the four steps in Power BI Desktop to connect to a shared semantic model?

Select Get data, choose Power BI datasets, select an existing dataset from the workspace, and create a report using a Live connection.

What specific term describes the reports commonly paired with Live Connection exam scenarios?

Thin reports