WebMD Data Analyst Interview Questions and Answers

Power bi assignment was given to solve

Q1. Optimization techniques in sql
Ans. 
Optimization techniques in SQL involve using indexes, query optimization, and proper database design.
• Use indexes on columns frequently used in WHERE clauses to speed up query performance

• Avoid using SELECT * and instead specify only the columns needed in the query

• Optimize queries by using appropriate join types and conditions

• Normalize database tables to reduce redundancy and improve query efficiency
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Q2. Sub queries in sql
Ans. 
Sub queries in SQL are queries nested within another query to retrieve data based on the result of the outer query.
• Sub queries can be used in SELECT, INSERT, UPDATE, and DELETE statements.

• They can be used to filter results, retrieve data from multiple tables, or perform calculations.

• Example: SELECT * FROM table1 WHERE column1 = (SELECT column2 FROM table2 WHERE condition);
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Q3. Types of Join in sql
Ans. 
Types of joins in SQL include inner join, left join, right join, and full outer join.
• Inner join: Returns rows when there is a match in both 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

• Full outer join: Returns all rows when there is a match in either table
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Q4. Time intelligence functions in power bi
Ans. 
Time intelligence functions in Power BI are used to analyze and compare data based on time periods.
• Time intelligence functions help in calculating year-to-date, month-to-date, and other time-based calculations.

• Functions like TOTALYTD, SAMEPERIODLASTYEAR, and PARALLELPERIOD are commonly used for time intelligence in Power BI.

• These functions allow for easy comparison of data across different time periods and help in tren
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Q5. Logical questions in aptitude
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Q6. Row level security in power bi
Ans. 
Row level security in Power BI allows users to restrict access to specific rows of data based on their role or criteria.
• Row level security can be implemented by creating roles in Power BI and defining rules to filter data based on user roles.

• Users can be assigned to specific roles which determine the data they have access to.

• Row level security helps in ensuring data privacy and compliance with regulations.

• For example, ...read more
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It was basic aptitude but it was online

Q1. Write python code for bizzbuss for prime or not prime\
Ans. 
Python code for determining if a number is prime or not and applying bizzbuzz logic.
• Write a function to check if a number is prime or not

• Iterate through a range of numbers and apply bizzbuzz logic

• Return 'prime' if the number is prime, 'bizz' if divisible by 3, 'buzz' if divisible by 5, and 'bizzbuzz' if divisible by both 3 and 5
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Q1. What time intelligence functions can be used for ytd and qtd analysis
Ans. 
Time intelligence functions like YTD (Year-to-Date) and QTD (Quarter-to-Date) can be used for YTD and QTD analysis in data analytics.
• YTD analysis can be done using functions like YTD() or TOTALYTD() to calculate values from the beginning of the year up to the selected date.

• QTD analysis can be done using functions like QTD() or TOTALQTD() to calculate values from the beginning of the quarter up to the selected date.

• Thes...read more
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Q2. Difference between import and direct query
Ans. 
Import brings data into Power BI for further analysis, while direct query connects to data source in real-time.
• Import: Data is loaded into Power BI for analysis, improving performance but requiring periodic refreshes.

• Direct Query: Connects to data source in real-time, allowing for up-to-date information but potentially slower performance.

• Import is suitable for smaller datasets, while direct query is better for large da
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