Sql Inter view questions?

 1.Difference between truncate and delete?

2. Difference between temp table and CTE and temp varibles?

3.Types of joins in sql?

4.What is the left join and left outer join?

5.Write an sql join query for below input

Table A:

ID

1

2

2

Null

Table B

ID

2

2

7

8

Null

6.How to optimize sql stored procedure?

7.What is the difference between primary key and foreign key?

8.What is merge and how it help for incremental load?

9.Types of views in sql?

10.What are types of indexs?

11.What column index?

 8.SSAS tabular model ?

Ans:

This is the most popular and interesting question which every interviewer will ask.

The tabular model era started form visual studio 2012 version on words and its keep on adding features to each 

version(2015,2017 till 2019).

1.Tabular Model:

a.This model is very faster compared to the multidimensional model.

b.The customized columns and measures can be added using DAX language.

c.Data can be export into a excel file and its useful to create Power Bi dashboard.

d.But in tabular only limitation is data if the data is more then the model get slow down.

Below are the steps to create tabular model:

Step1:

Step2:

Step3: Select data source

Step4: Select sql server 

Step5: Select the server name and the database where the tables exist

Step6:Select the option to get the data

Step7:We can use based on our requirement like,table select or qury writing

Step8:Select the dimension or facts which required for your model

Filter Visual

 7.What is visual level filter?

Ans: Visual level filter is used to filter the data in the dashboard and it interact with our report.

In a simple example:

If you open any online retail app like (Amazon,filpkart) there is a drop down and it will show all the category like(Electronics,Men,woman etc) ,when you select electronics it will show the report of the electronic gadgets.

Below is the practical example about Covid-19 details:

Scenario:In below screen i have represented total covid cases and test&death rate of each location

  1.Types of source used in Power BI Desktop?

Ans:   There multiple data source which we used to extract our source data ,But based on our business requirements will decide and use those data source connection.

Most frequently will use below data sources in my current dashboard.

2.Types of Filters available in Power BI?

Ans:Most commonly real time will use below filters

1.Visual Level Filter

2.Report Level Filter

3.Bi-directional cross filter

3.What are the visuals mostly used in Power BI dashboard?

Ans: There are many visuals available in power bi desktop some are predefined and some are customized,

In my real time i have used below visual  to re present data accurately.

1.Line chart:-Its very use fully to represent the sum of sales based on Location/Product wise.

2.Pie chart:-Its Very use full to represent the sales present(%) of each store wise or Location wise.

3.Filter:-Used to filter the location wise sales like (US,Canada,UK)

4.Card:-Used to represent total sales of all Geo graphic locations

5.Slicer:-Slicer are useful to sort the report data.

6.ArcGis Map-Previously we have Bing maps now in the latest version used ArcGis which is very help full to connect google maps. 

7.Clustered Column Chart:- It will be use full to represent and show the total sales vs Discounts . 

4.What is live connection mode in Power BI?

Ans: Live connection mode is the one of the best option to connection azure SSAS cube and the power BI dashboard.

But there are some cons in this method

1.4If the data volume is high then the power BI dashboard will give bad performance./

5.Difference between Live connection mode and Direct connection in power BI? 

Ans:Below are the differences which observed on Live connection and direct connection.

1.Live connection:

a.This mode we dint have option to write any customized query

b.Limited data its give best performance

2.Direct Connection:

a.This mode will connect SSAS model which deployed on server and there will retry the table data using sql query like below way.

B.Its very faster relative of back end data .

C.We can set query time out value to check if query is not running usual manner and its help full to optimize query.

6.What is the bi-directional filer  ?

Ans:Bi-directional cross filter are used to filter the multiple dimensional data in the model level.Again it based on our scenario we can apply this filter like below.

Thank you,I will share the next set of answers in my next post.

Thank you

Karthik.

Power Bi Interview Questions

 Top 20 Power BI Interview Questions

1.Types of source used in Power BI Desktop?

2.Types of Filters available in Power BI?

3.What are the visuals mostly used in Power BI dashboard?

4.What is live connection mode in Power BI?

5.Difference between Live connection mode and Direct connection in power BI?

6.Explain advantage of using Import connection mode compared to direct connection mode?

7.What is the bi-directional filer  ?

8.What is visual level filter?

9.What is book mark report and how its helps in the power Bi dash board?

10.How to apply column level security in Power BI?

11.What is Role based security and can it be applied in datasets level?

12.What is the difference between tabular model cube & Multidimensional cube?

13.Explain the pros and cons of using tabular model cube data?

14.Can we create Date table in power bi?

15.What are the types of relations ships available in power bi?

16.What are the type of Gateways available in Power Bi?

17.What is a Gate way and what is the need of it?

18.What is the difference between Calculate and Sum functions?

19.What is the difference between  ALL & ALL Selected in DAX?

20.How to Schedule a Power BI report?

I will Post the answers with explanation in my next post.

Thanks,

Karthik.