Databases / SQL
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To find the top 10 most common values in a given column with millions of rows, you can use a SQL query.
About this solution: The candidate's solution is optimal and demonstrates a complete understanding of the problem. The candidate has used the GROUP BY and ORDER BY clauses to group the values and order them by count, and the LIMIT clause to limit the number of rows returned.
Given a table of data with employee IDs, names, and salaries, write a SQL query to find the highest paid employee.
About this solution: The candidate's solution is correct and demonstrates a good understanding of SQL.
This technical problem deals with writing a query that returns the average salary of employees in each department. The given table includes information on the department, employee, and salary. The expected output is a table that lists the department and the average salary for that department.
About this solution: This solution is complete and solves the problem. The approach is straightforward and easy to follow.
The goal is to design a backup and recovery solution that will work in both a single server and a distributed system environment. The solution needs to be able to scale up or down as the number of databases or users increases or decreases.
About this solution: The candidate's solution is incomplete. The candidate does not mention how the backup and recovery solution will work in a distributed system. The candidate also does not mention how the solution will scale up or down as the number of databases or users increases or decreases.
To find the top 3 customers with the highest average order value, you can use a SQL query. This query will take the customer data from a table and find the 3 customers with the highest average order value.
About this solution: This solution is optimal because it uses the GROUP BY and ORDER BY clauses to group the data by customer ID and then order the data by the average order value. The LIMIT clause is used to limit the results to the top 3 customers.
The table given contains information on employees, including their ID, name, manager ID, and department. The goal is to write a SQL query that returns the ID and name of all employees who are not managers and who are in the Sales department. From the given example input, the expected output would be the ID and name of Joe and Karen.
About this solution: The candidate's solution is correct and demonstrates a good understanding of SQL. The candidate has correctly used the WHERE clause to filter out the rows that do not meet the criteria. The candidate has also correctly used the IS NULL operator to check for employees who are not managers.
Given a table with two columns, "name" and "parent", write a SQL query to find all the children of the parent "A".
About this solution: The candidate's solution is correct and demonstrates a good understanding of SQL. The solution is also efficient, using the WHERE clause to filter the results.
To find the third highest salary in a table, you can use a simple ORDER BY and LIMIT clause in SQL.
About this solution: The candidate's solution is correct and uses an optimal approach.