ShareChat Production Analyst Interview Questions and Answers

Calculate the average n days retention for all users given their user ID, date, activity table, and a table with the date of joining for each user.

• Join the activity table with the user table using the user ID

• Calculate the number of days between the date of joining and the activity date

• Filter out the activities that occurred after n days

• Calculate the average retention for all users

Race 5 horses at a time to find the 5 fastest horses out of 25.

• Divide the horses into 5 groups of 5 horses each.

• Race all the horses in each group and note down the timings.

• The top 3 horses from each group move to the next round.

• Race all the horses that made it to the next round and note down the timings.

• The top 2 horses from this round move to the final round.

• Race these 2 horses and the fastest one is the winner.

• The to...read more

To remove duplicates from two columns, use DISTINCT keyword in SELECT statement.

• Use SELECT DISTINCT to retrieve unique combinations of two columns.

• Combine the two columns using CONCAT function before applying DISTINCT.

• Example: SELECT DISTINCT CONCAT(column1, column2) FROM table_name;