21n78e Creative Labs Data Analyst Interview Questions and Answers

SQL Joins are used to combine rows from two or more tables based on a related column between them.

• SQL Joins are used to retrieve data from multiple tables based on a related column between them.

• Common types of SQL Joins include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN.

• Example: SELECT * FROM table1 INNER JOIN table2 ON table1.column = table2.column;

Python numpy provides various functions for numerical operations on arrays.

• numpy.sum() - calculates the sum of array elements

• numpy.mean() - calculates the mean of array elements

• numpy.max() - returns the maximum value in an array

• numpy.min() - returns the minimum value in an array

• numpy.std() - calculates the standard deviation of array elements

Union combines and removes duplicates, Union All combines without removing duplicates.

• Union combines result sets and removes duplicates

• Union All combines result sets without removing duplicates

• Union is slower than Union All as it involves removing duplicates

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

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

To show top 5 in pandas, use the nlargest() function.

• Use the nlargest() function with the 'n' parameter set to 5 to get the top 5 values in a pandas DataFrame.

• For example: df['column_name'].nlargest(5) will return the top 5 values in the specified column.

A scatter plot is a better representation for 3 numerical columns.

• Use a scatter plot to show the relationship between the numerical columns.

• Scatter plots are effective for visualizing correlations and patterns in data.

• Each point on the plot represents a data point with values from all 3 columns.

Possible reasons for drop in CPM include seasonality, changes in ad inventory, shifts in audience demographics, and increased competition.

• Seasonal fluctuations in advertising demand

• Changes in available ad inventory

• Shifts in audience demographics affecting targeting effectiveness

• Increased competition leading to lower bids

Types of floors in GAM include carpet, hardwood, tile, and laminate.

• Carpet

• Hardwood

• Tile

• Laminate

Joins are used in databases to combine rows from two or more tables based on a related column between them.

• Joins are used to retrieve data from multiple tables based on a related column between them

• Common types of joins include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN

• Example: SELECT * FROM table1 INNER JOIN table2 ON table1.column = table2.column

Processing speed of scripting languages varies based on factors like code complexity and optimization.

• Processing speed can vary based on the specific task being performed.

• Compiled languages like C++ tend to be faster than interpreted languages like Python.

• Optimizing code can improve processing speed.

• JavaScript can be faster than Python for certain tasks.

• Consider using libraries or frameworks optimized for performance.

Data validation ensures data is accurate and useful. Delete removes specific records, truncate removes all records, drop removes entire table.

• Data validation ensures data is accurate, complete, and useful for analysis

• Delete removes specific records from a table based on a condition

• Truncate removes all records from a table, but keeps the table structure

• Drop removes an entire table from the database

• Example: DELETE FROM t...read more