Interview questions for Power BI

Power BI came into existence in late 2013 after Microsoft had decided to combine multiples excel add-on to create a complete new and independent tool. Power BI has been the major contributing factor for Microsoft’s growth in the domain of Business Intelligence and Data Visualization in the year 2016-17.

1. What is BI?

Business intelligence is a technology-driven method. It helps you to analyze data and to provide actionable information which helps corporate executives, business managers, and other users to take decisive business decisions.

2. What is a Power BI?

Power BI is a Business Intelligence and Data Visualization tool which helps you to convert data from the various data source into interactive dashboards and BI reports. It provides multiple software connectors and services.

3. What are the parts of Microsoft self-service business intelligence solution?

Microsoft has two parts for Self-Service BI
Parts of Self-Service BI
Excel BI Toolkit It allows users to create an interactive report by importing data from different sources and model data according to report requirement.
Power BI It is the online solution that enables you to share the interactive reports and queries that you have created using the Excel BI Toolkit

4. Why use Power BI?

Here are four primary reasons for using Power BI tool:
• Pre-built dashboards and reports for SaaS Solutions.
• Power BI allows real-time dashboard updates.
• Offers Secure and reliable connection to your data sources in the cloud or on-premises
• Power BI offers fast deployment, hybrid configuration, and secure environment.
• Helps you in data exploration using natural language query.

5. What is self-service business intelligence?

Self-Service Business Intelligence (SSBI)
• SSBI is an approach to data analytics that enables business users to filter, segment, and, analyze their data, without the in-depth technical knowledge in statistical analysis, business intelligence (BI).
• SSBI has made it easier for end users to access their data and create various visuals to get better business insights.
• Anybody who has a basic understanding of the data can create reports to build intuitive and shareable dashboards.

6. What is Dax Function?

It is a formula expression language called (DAX) that can be used with various visualization tools like Power BI. It is also known as a functional language, where the full code is kept inside a function.

7. What data sources can Power BI connect to?

The list of data sources for Power BI is extensive, but it can be grouped into the following:
• Files: Data can be imported from Excel (.xlsx, xlxm), Power BI Desktop files (.pbix) and Comma Separated Value (.csv).
• Content Packs: It is a collection of related documents or files that are stored as a group. In Power BI, there are two types of content packs, firstly those from services providers like Google Analytics, Marketo or Salesforce and secondly those created and shared by other users in your organization.
• Connectors to databases and other datasets such as Azure SQL, Databaseand SQL, Server Analysis Services tabular data, etc.

8. What are Building Blocks in Power BI?

The following are the Building Blocks (or) key components of Power BI:

1. Visualizations: Visualization is a visual representation of data.
Example: Pie Chart, Line Graph, Side by Side Bar Charts, Graphical Presentation of the source data on top of Geographical Map, Tree Map, etc.

2. Datasets: Dataset is a collection of data that Power BI uses to create its visualizations.
Example: Excel sheets, Oracle or SQL server tables.

3. Reports: Report is a collection of visualizations that appear together on one or more pages.
Example: Sales by Country, State, City Report, Logistic Performance report, Profit by Products report etc.

4. Dashboards: Dashboard is single layer presentation of multiple visualizations, i.e we can integrate one or more visualizations into one page layer.
Example: Sales dashboard can have pie charts, geographical maps and bar charts.

5. Tiles: Tile is a single visualization in a report or on a dashboard.
Example: Pie Chart in Dashboard or Report.

9. What are the data types of Dax?

Data types of Dax are: 1) Numeric, 2) Boolean, 3) DateTime, 4) String, and 5) Decimal.

10. What are the essential applications of the Power BI?

Power BI is mainly used by:
• PMO – Project Management Office
• Business & Data Analyst
• Developer & Database Administrator
• IT Team, IT Professional
• Consumer for End User Report
• Data Scientist

11. What are the most common DAX Functions used?

Below are some of the most commonly used DAX function:
• SUM, MIN, MAX, AVG, COUNTROWS, DISTINCTCOUNT
• IF, AND, OR, SWITCH
• ISBLANK, ISFILTERED, ISCROSSFILTERED
• VALUES, ALL, FILTER, CALCULATE,
• UNION, INTERSECT, EXCEPT, NATURALINNERJOIN, NATURALLEFTEROUTERJOIN,
SUMMARIZECOLUMNS, ISEMPTY,
• VAR (Variables)
• GEOMEAN, MEDIAN, DATEDIFF

12. What is Power Pivot?

Power Pivot is an add-in for Microsoft Excel 2010 which enables to import millions of rows of data from multiple data sources into a single Excel workbook.
It allows to create relationships between heterogeneous data, creates calculated columns and measures using formulas, builds PivotTables, and PivotCharts. Then you can analyze the data so that you can make timely business decisions without requiring IT assistance.

13. What is power Pivot data table?

Power Pivot data table is a model which is made up of tables, data types, columns, and table relations. These data tables are constructed for holding the data for a business entity.

14. What is Power Query?

Power query is an ETL tool which is used to shape, clean, and transform data using intuitive interfaces without having to use coding. It helps the user to:
o Import the data from a wide range of sources from files, big data, databases, and social media data, etc.
o Join and append the data from multiple data sources.
o Shape the data as per requirement by adding and removing the data.
As you can see there is a major moment of Microsoft in the year 2017 when compared to 2016 and this is mainly due to the contribution oferal Power BI. In case you are still not convinced about moving into the Power BI domain, below image will give you an idea about the current market for Power BI.