Interview Questions and Answers

Columns are the fields in a dataset, while measures are calculations based on those fields in Power BI.

• Columns are the raw data fields in a dataset, such as 'Sales Amount' or 'Product Category'.

• Measures are calculations performed on columns, like sum, average, count, etc.

• Measures are created using DAX (Data Analysis Expressions) in Power BI.

• Columns are used for grouping, filtering, and slicing data, while measures are used for calculations and aggregations.

Asking for clarification shows engagement and interest in the conversation.

• Asking for clarification demonstrates active listening and a desire to fully understand the topic.

• It can also help clarify any misunderstandings or uncertainties, leading to more productive discussions.

• Examples: 'Could you please explain that concept in more detail?' or 'I'm not sure I understand, could you provide an example?'

A/B testing is a method used to compare two versions of an application to determine which one performs better.

• A/B testing involves randomly dividing users into two groups: one group receives version A of the application, while the other group receives version B.

• Key metrics are measured for each group to determine which version performs better.

• A statistically significant sample size is necessary to ensure reliable results.

• Examples of metrics to measure include conversion rates...read more

Different kinds of joins include inner join, outer join, left join, and right join.

• Inner join: Returns only the rows that have matching values in both tables.

• Outer join: Returns all rows when there is a match in one of the tables.

• Left join: Returns all rows from the left table and the matched rows from the right table.

• Right join: Returns all rows from the right table and the matched rows from the left table.

Use the DISTINCT keyword in a SELECT statement to remove duplicates in SQL.

• Use the DISTINCT keyword in a SELECT statement to retrieve unique values.

• Example: SELECT DISTINCT column_name FROM table_name;

• Another way is to use the GROUP BY clause to remove duplicates.

• Example: SELECT column_name FROM table_name GROUP BY column_name;

Query to retrieve the current date and time in SQL Server

• Use the GETDATE() function in SQL Server to retrieve the current date and time

• Example: SELECT GETDATE() AS CurrentDateTime;