Power BI Interview Questions Part -1

 

 

POWER BI INTERVIEW QUESTIONS

1.      What is Difference between PowerBI and Tableau?

 Tableau is primarily a data visualization Tool, PowerBI is both ETL and Data Visualization Tool ,it  also has lot of data modelling options Power BI is a tool use for easy visualization and is freely available for desktop version and can be use standalone. It has ETL tools which are similar to Excel Power Query which make it easy and comfortable It also can add external visuals to make the report attractive and interactive, Tableau is a Similar Visualization Tool but is paid version although no additional visual is needed to be added but to create the visual in tableau, it requires good skill and understanding of charts and tableau tools.

2.  Which are the other Data Visualization Tools in Market ?

        Google Data Studio, Excel Power Pivot, Power Map, SAP Business Objects BI Suite, TIBCO Spotfire, Looker, Tableau, QlikView, Plotly, IBM Whatson.

 

3.       What is ETL ?

ETL Stands for Extract Transform Load, ETL tools are used to convert raw data into structured tabular format, and which records the steps performed which can be applied automatically on future loaded files.

 

4.       Which is the ETL Component of POWERBI ?

Power Query is the ETL part of PowerBI additionally the same tool is available in excel as well.

 

5.       Describe the different components of PowerBI ?

PowerBI Desktop - PowerQuery – PowerPivot – PowerView – PowerBI Service – PowerBI MobileApps, Power BI Data Flow, Power Map, Power Q&A.

 

6.       Which are the other ETL Tools in Market ?

Informatica PowerCenter, Abinitio, Alteryx, SSIS, Spotfire, IBM DataStage, Oracle Data Integrator, SAS Data Management, Talend Open Studio, Pentaho Data Integration, Singer, Hadoop, etc.

 

7.       What are the different data sources connectivity available in PowerBI ?

PowerBI offers more than 300 different data sources support . Excel ,CSV,JSON,Folder,Web,PDF,SQL Server,MYSQL,Azure SQL Database,SAP HANA,Amazon RedShift,Teradata are some of the common data sources

 

8.       What is PowerBI, why is it used for ?

Power BI is a Business Intelligence Tool, It is collection of software services, apps, and connectors that work together to turn your unrelated sources of data into coherent, visually immersive, and interactive insights

 

9.       What is the difference between Direct Query mode and Import Mode ?

A Direct Query connection will run queries directly to your source at run time/Realtime. In the Import method, Power BI captures a snapshot of your data and caches it in Power BI Desktop.

 

10.   What is the advantage of Import Mode over Direct Query Mode ?

As the data is cached in Import Mode,Refresh time is faster in Import Mode compared to Direct query mode ,Although many transformations in PowerQuery and some DAX functions wont work in Direct Query Mode

 

11.   What is the advantage of Direct Query Mode over Import Mode?

Since the Data is stored at the Source in Direct Query Mode not in POWERBI Cache, we can overcome the POWERBI Size limitations for data and we get Live data as we can set timer of refresh as low as 5 sec

 

12.   What is dual mode in Power BI?

 The dual storage mode is between Import and Direct Query. it is a hybrid approach, Like importing data, the dual storage mode caches the data in the table

 

13.   What Language does Power Query use ?

M Language or Mash up Language

 

14.   What are the different formats in which PowerBI is available ?

PowerBI Desktop,PowerBI Service,PowerBI Mobile App

 

15.   Where is the data stored in PowerBI ?

Azure Blob Storage, Azure SQL Database and other cloud base storage depends on Microsoft Tieups.

 

16.    What are the available views ?

Report View,Data View,Modelling View

 

17.   What is PowerQuery ?

PowerQuery is the ETL Component of PowerBI Which is used to connect multiple data sources and do some transformations also referred as data cleaning or data massaging

 

18.   Describe Merge Query from Transform tab in PowerQuery ?

Merge Query is used to combine data from different tables based on common column, It is similar to joins in SQL and VLOOKUP from Excel.

19.   What are the different types of Joins there in Merge Query?

Inner Join,Left Join,Right Join,Full Join,Left Anti,Right Anti

 

20.   What is Inner Join in Merge Query ?

 Inner join returns all Matching Rows from both Tables