Games24x7 Data Analyst 2 Interview Questions and Answers

Q1. What is the difference between Union and Union all ?
Ans. 
Union combines the results of two or more SELECT statements, while Union all includes all rows, including duplicates.
• Union removes duplicate rows from the result set, while Union all includes all rows.

• Union sorts the result set, while Union all does not.

• Union is slower than Union all because it performs a distinct operation.

• Example: SELECT column1 FROM table1 UNION SELECT column1 FROM table2;

• Example: SELECT column1 FRO
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Q2. Which query is more faster , joins or union?
Ans. 
Joins are generally faster than unions.
• Joins are typically faster than unions because they combine data from multiple tables based on a common column, while unions combine data from multiple queries into a single result set.

• Joins can utilize indexes on the columns being joined, which can improve performance.

• Unions involve combining the results of multiple queries, which can be slower as it requires merging and sorting ...read more
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SQL based leetcode medium and hackerrank

Python take home EDA case study assessment

Different question were asked on sql python java

70 Technical and Aptitude mcqs to solve in 50 minutes

Q1. What is overloading and overriding?
Ans. 
Overloading is having multiple methods with the same name but different parameters. Overriding is implementing a method in a subclass that is already defined in the parent class.
• Overloading allows a class to have multiple methods with the same name but different parameters.

• Overriding occurs when a subclass provides a specific implementation of a method that is already provided by its parent class.

• Overloading is resolve...read more
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Q2. What is difference between Primary and unique key in dbms?
Ans. 
Primary key uniquely identifies a record in a table, while unique key ensures all values in a column are distinct.
• Primary key does not allow NULL values, while unique key allows one NULL value.

• A table can have only one primary key, but multiple unique keys.

• Primary key is a combination of unique and not null constraints.

• Primary key is used to establish relationships between tables, while unique key is used to enforce un
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DSA, problem solving

System design interview and prior experience in projects

Q1. What was the toughest problem you encountered in your previous assignments ?
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Q2. Given a choice, what would you have done differently in your previous assignments ?
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Three coding online assessments - screening round.

Two to three coding questions based on dynamic programming.

Q1. Resume based and computer network
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Q1. Simple hr question
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Q1. Tell me about yourself
Ans. 
Experienced Senior Software Engineer with a passion for problem-solving and creating innovative solutions.
• Over 8 years of experience in software development

• Proficient in multiple programming languages such as Java, Python, and C++

• Strong background in designing and implementing scalable systems

• Led successful projects such as developing a real-time data analytics platform for a Fortune 500 company
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Q2. About techstacks
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