Power BI Interview Questions
By: Great Learning
Tags: Power Bi Tutorials, Interview, Power Bi, Interview Questions

Contributed by: Sambit Mishra

Please find below the rundown of top 20 Power BI Interview Questions and Answers that are highly likely to be asked by the interviewers.

1). Define the parts of Microsoft self-service business intelligence solution?

Microsoft has two sections for Self-Service BI

2). What do you mean by self-service business intelligence?

Self-Service Business Intelligence (SSBI)

SSBI is a way to deal with data analytics that empowers business users to filter, segment, and, break down their data, without the in depth technical knowledge in statistical analysis, business intelligence (BI).

SSBI has made it simpler for end clients to get to their data and make different visuals to better business insights.

Anyone who has a basic comprehension of the data can create reports to build informative and shareable dashboards.

3). What is Power BI?

It is a cloud-based data and information sharing environment. Once we have created reports utilizing Power Query, Power Pivot and Power View, we can share our insights/inferences with our friends/colleagues. Power BI, which is a part of SharePoint on the web, lets us load Excel workbooks into the cloud and share them with a chosen group of users. Apart from that, our colleagues can interact with our reports to apply filters and slicers to feature data. They are completed by Power BI, a basic way of sharing our analysis and investigation from the Microsoft cloud.

Power BI features permits us to:

Share presentations and queries with our friends/colleagues.

Update our Excel file from data or information sources that can be in the cloud.

Display the output on multiple devices. This incorporates PCs, tablets, & HTML 5-empowered mobile devices that utilize Power BI application.

Query our data using natural language processing (NLP).

4). What do you know about Power BI Desktop?

Power BI Desktop is a free desktop application which can be installed on a computer. Power BI Desktop works in cohesion with the Power BI service by providing data exploration, shaping, modelling, and making reports with profoundly intuitive visualizations. We can save our work to a file or publish our data and reports to our Power BI site to share with other users.

5). What data sources can Power BI associate with?

The rundown of data sources for Power BI is broad, but it can be classified into the following:

Files : Data can be imported from Excel, Power BI Desktop files and CSV files.

: Data can be imported from Excel, Power BI Desktop files and CSV files. Content Packs : It is a assortment of related files that are stored as a group. In Power BI, there are two types of content packs, one from services providers like Google Analytics, or Salesforce and other from those made and shared by other users in our organization.

: It is a assortment of related files that are stored as a group. In Power BI, there are two types of content packs, one from services providers like Google Analytics, or Salesforce and other from those made and shared by other users in our organization. Connectors to databases and different datasets such as Azure SQL, Database and SQL Server Analysis Services tabular data, and so on.

6). What are key components in Power BI?

Following are the key components of Power BI:

Visualizations: Visualization is a visual portrayal of data. For example: Pie Chart, Line Graph, Side by Side Bar Charts, Graphical Presentation of the source data on top of Geographical Map, Tree Map, and so forth. Datasets: Dataset is an assortment of data that Power BI uses to create its visualizations.

For example: Excel sheets, Oracle or SQL server tables, and so on. Reports: Report is an assortment of visualizations that show up together on at least one or more pages.

For example: Sales by Country, State, City Report, Logistic Performance report, Profit by Products report, and so forth. Dashboards: Dashboard is single layer introduction of multiple visualizations, i.e. we can congregate one or more visualizations into one page layer.

For example: Sales dashboard can have pie charts, topographical maps and bar charts. Tiles: Tile is a solitary visualization in a report or on a dashboard.

For example: Pie Chart in Dashboard or Report.

7). What are the various types of filters in Power BI Reports?

Power BI provides a multitude of options to filter reports, data and visualization. The following are the rundown of Filter types:

Visual-level Filters: These filters work on just an individual visualization or perception, diminishing the measure of data that the representation can see. Besides, visual-level filters can filter data as well as calculations.

These filters work on just an individual visualization or perception, diminishing the measure of data that the representation can see. Besides, visual-level filters can filter data as well as calculations. Page-level Filters: These filters basically work at the report-page level. Various pages in the similar report can have diverse page-level filters.

These filters basically work at the report-page level. Various pages in the similar report can have diverse page-level filters. Report-level Filters: These filters deal with the entire report, filtering all pages and visualizations included as part of the report.

Power BI visual, as we know, has interactions feature, which makes filtering a report a quick activity. Visual interactions are helpful, yet they come with certain limitations:

The filter is not spared as part of the report. Whenever we open a report, we can start to play with visual filters yet it is extremely unlikely to store the filter in the saved report.

The filter is always ostensible. In some cases, we want a filter for the whole report, but we do not want any visual sign of the filter being applied.

8). What are content packs in Power BI?

Content packs for services are pre-built solutions for popular services as a part of the facility BI experience. A subscriber to a service can very fast connect to their account from Power BI to see data through live dashboards and interactive reports that have been already built for them. Microsoft has content packs for popular services like Salesforce.com, Adobe Analytics, Azure Mobile Engagement, and so on. Organizational content packs make way for users, Business Intelligence professionals, and system integrator, the tools to create their own content packs to share purpose-built dashboards, reports & datasets within their organization.

9). What is DAX?

To do basic calculation and data analysis on data in power pivot, we use Data Analysis DAX). It is a formula language that is used to compute calculated columns and calculated fields.

• DAX works on column values.

• DAX cannot modify or insert data.

• We can create calculated columns and measures with DAX, however we can’t calculate rows using DAX.

10). What are the foremost common DAX Functions used?

Below are a number of the foremost 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

11). How is the FILTER function used?

The FILTER function returns a table with a filter condition applied for every of its source table rows. The FILTER function is never utilized in isolation; it’s generally used as a parameter to other functions like CALCULATE.

• FILTER works like an iterator and can negatively impact performance over large source tables.

• Complex filtering logic can be applied like referencing a measure in a filter expression.

o FILTER (MyTable, [SalesMetric] > 500)

12). What’s unique about the CALCULATE and CALCULATETABLE functions?

These functions are the sole functions that allow us to switch the filter context of measures or tables.

• By adding to the existing filter context of queries.

• By overriding filter context from queries.

• By removing existing filter context from queries.

Limitations:

• Filter parameters can only operate one column at a time.

• Filter parameters cannot reference a metric.

13). What’s the common table function for grouping data?

SUMMARIZE()

• Main groupby function in SSAS.

• The practice that is recommended is to specify table and group by columns but not metrics. We can use ADDCOLUMNS function.

SUMMARIZECOLUMNS

• New group by function for SSAS and Power BI Desktop which is more efficient.

• Specify groups by columns, table, and expressions.

14). What are the various benefits of using Variables in DAX ?

Below are a number of the benefits:

• While declaring & evaluating a variable, the variable is often reused multiple times during a DAX expression, thus avoiding additional queries of the source database.

• Variables can only make DAX expressions more logical to interpret.

• Variables can only be scoped to their measure/query, as they can’t be shared among measures, queries or be defined at the model level.

15). How do we create trailing X month metrics via DAX against a non-standard calendar?

The solution will involve:

1. CALCULATE function to regulate (take over) filter context of measures.

2. ALL to get rid of existing filters on the date dimension.

3. FILTER to spot which rows of the date dimension to use.

Alternatively, CONTAINS could also be used:

• CALCULATE(FILTER(ALL(‘DATE’),…….))

16). What are the various Excel BI add-in?

Below are the foremost important BI add-in to Excel:

• Power Query: It helps find , editing and loading external data.

• Power Pivot: It is primarily used for data modelling and data analysis.

• Power View: It’s used to design visual and interactively reports.

• Power Map: It helps us to display insights on 3D Maps.

17). What’s Power Pivot?

Power Pivot is an add-in for Microsoft Excel 2010 that permits you to import many rows of knowledge from multiple data sources into one Excel workbook. It allows us to create relationships between data that is heterogeneous in nature, build calculated columns and measures using formulas, build PivotTables and PivotCharts. We will have to then further analyse the information in order to make timely business decisions without requiring any IT assistance.

18). What’s Power Pivot Data Model?

It is a model that’s made from data types, tables, columns, and table relations. These data tables are primarily constructed for holding data for a business entity.

19). What’s xVelocity in-memory analytics engine utilized in Power Pivot?

The main engine behind power pivot is that the xVelocity in-memory analytics engine. It can handle great deal of knowledge because it stores data in columnar databases, and in memory analytics which ends up in faster processing of knowledge because it loads all data to RAM memory.

20). What are the differences in data modelling between Power BI Desktop and Power Pivot for Excel?

We have a number of the differences enlisted below:

• Power BI Desktop has a process for supporting bi-directional cross filtering relationships, security, calculated tables, and Direct Query options.

• Power Pivot for Excel has one to many relationships, supports only calculated columns, and supports only import mode. Security roles can’t be defined in Power Pivot for Excel.