CTS Consulting & Technical Support Power BI Developer Interview Questions and Answers

Direct query mode connects to data source in real-time, while import mode loads data into Power BI for faster analysis.

• Direct query mode connects to data source in real-time, providing up-to-date data

• Import mode loads data into Power BI for faster analysis, but may not always reflect real-time changes

• Direct query mode is suitable for large datasets that require real-time updates

• Import mode is suitable for smaller datas

PowerBI is a data visualization tool that helps users analyze and visualize data to make informed business decisions.

• PowerBI helps in creating interactive reports and dashboards

• It allows users to connect to various data sources like Excel, SQL databases, and cloud services

• Users can create custom visualizations and share insights with others

• PowerBI can be used for data exploration, data modeling, and data storytelling

End users can access the report through Power BI Service, Power BI Mobile App, or embedded in other applications.

• End users can access the report through Power BI Service by logging in with their credentials

• End users can also access the report through Power BI Mobile App on their smartphones or tablets

• Reports can be embedded in other applications using Power BI Embedded feature

Data Gateway can be installed in Power BI by downloading and running the installer.

• Download the Data Gateway installer from the Power BI service

• Run the installer and follow the installation wizard

• Sign in with your Power BI account to register the gateway

Star schema has a single fact table connected to multiple dimension tables, while snowflake schema has normalized dimension tables.

• Star schema denormalizes dimension tables, making it easier to query but potentially less efficient for storage.

• Snowflake schema normalizes dimension tables, reducing redundancy but potentially making queries more complex.

• Star schema is commonly used for data warehouses with denormalized da...read more

The GROUP BY clause is used in SQL to group rows that have the same values into summary rows.

• It is used with aggregate functions like COUNT, SUM, AVG, etc.

• It helps in summarizing data and generating reports.

• It is often used in conjunction with the HAVING clause to filter grouped data.

• Example: SELECT department, COUNT(employee_id) FROM employees GROUP BY department;

Measure is a calculated value based on data in a model, while count is a simple count of records.

• Measure is a calculated value based on aggregation functions like sum, average, etc.

• Count is a simple count of records in a dataset.

• Measures are used in Power BI to perform calculations on data, while count is used to simply count the number of records.

Row level security is a feature in Power BI that restricts data access at the row level based on user roles or criteria.

• Allows users to only see data that is relevant to them

• Can be implemented using DAX expressions

• Helps in maintaining data privacy and security

• Useful for organizations with sensitive data

Relationships in Power BI define how different tables are connected to each other.

• Relationships define how tables are related to each other based on common fields

• They are used to create connections between tables for data analysis

• Relationships can be one-to-one, one-to-many, or many-to-many

• They are essential for creating accurate and meaningful visualizations in Power BI

We used a variety of data sources including SQL databases, Excel files, and web APIs.

• SQL databases

• Excel files

• Web APIs