PL-300 Exam

Which storage mode leaves the data at the data source?

• Import

• Direct Query

• Dual

Which technology improves performance by generating a single query statement to retrieve and transform source data?

• Query folding

• Adding index columns

• Adding custom columns with complex logic

Answer explanation

It reduces the amount of data transferred between the data source and Power BI, leading to faster data retrieval and report generation.

What type of import error might leave a column blank?

• Keep errors

• Unpivot columns

• Data type error

Answer explanation

Sometimes, when you import data into Power BI, the columns appear blank. This situation happens because of an error in interpreting the data type in Power BI. The resolution to this error is unique to the data source

You have the following three versions of an Azure SQL database:
- Test
- Production
- Development
You have a dataset that uses the development database as a data source.
You need to configure the dataset so that you can easily change the data source between the development, test, and production database servers from powerbi.com.

• Create a JSON file that contains the database server names. Import the JSON file to the dataset.

• Create a parameter and update the queries to use the parameter.

  
  

• Create a query for each database server and hide the development tables.

• Set the data source privacy level to Organizational and use the ReplaceValue Power Query M function.
  

Answer explanation

As you can't edit datasets data sources in Power BI service, we recommend using parameters to store connection details such as instance names and database names, instead of using a static connection string. This allows you to manage the connections through the Power BI service web portal, or using APIs, at a later stage.

You have an Azure SQL database that contains sales transactions. The database is updated frequently.
You need to generate reports from the data to detect fraudulent transactions. The data must be visible within five minutes of an update.

How should you configure the data connection?

• Add a SQL statement.

• Set Data Connectivity mode to DirectQuery.

• Set the Command timeout in minutes setting.

• Set Data Connectivity mode to Import.

Answer explanation

With Power BI Desktop, when you connect to your data source, it's always possible to import a copy of the data into the Power BI Desktop. For some data sources, an alternative approach is available: connect directly to the data source using DirectQuery.
DirectQuery: No data is imported or copied into Power BI Desktop. For relational sources, the selected tables and columns appear in the Fields list. For multi-dimensional sources like SAP Business Warehouse, the dimensions and measures of the selected cube appear in the Fields list. As you create or interact with a visualization, Power BI Desktop queries the underlying data source, so you re always viewing current data.

You plan to publish your SSAS Tabular (live connection) data model to Power BI Service. What must be used in order for this to be possible?

• Data Gateway

• Dual Storage Mode

• Parameters

• Admin Privileges

Answer explanation

Data Gateways are required for on-premises data sources, like SSAS Tabular live connections.

What is the Query Editor used for?

• As a cloud-based storage option for your organization's data

• To shape & transform data, then load it into Power BI

• To create relationships between data and lookup tables

• To create measures & calculated columns using DAX
  

Answer explanation

Once you connect to data, the Query Editor lets you shape & transform the data to meet your needs, then load that model into Power BI Desktop

In which storage mode are tables solely stored in-memory and queries fulfilled by cached data?

• Import

• DirectQuery

• Dual

• Native

Answer explanation

In import storage mode, tables are stored in-memory, whereas in DirectQuery tables are connected directly to the source. Dual storage mode allows tables to come from in-memory data or by an on-demand query to the data source.

When should you use DirectQuery?

• The source data never changes

• Company policy states no data source restrictions

• Dataset is too large to be stored in-memory

• All of the above

Answer explanation

Use DirectQuery when the dataset is too large to be stored in-memory, when the source data changes frequently & reports must show the most recent data, and when the company policy states data can only be accessed from the original source.

How can you use parameters when connecting to data?

• To connect to a JSON file

• To change data source values dynamically

• To create "What-If" scenarios

• To shape and transform data in the Query Editor

Answer explanation

Parameters are a useful way to change data source values dynamically in Power Query. These parameters are different from the "What-If" parameters created in the Power BI Desktip front-end.