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Above-Average Departments (Derived Table)
Google's calibration committee wants to flag above-average performers by comp for mid-year review discussions. Using a subquery in the FROM clause (derived table), find employees whose salary exceeds their department's average salary. Show name, department, salary, dept_avg (rounded to nearest dollar), and above_avg_by (how much they exceed the average, rounded to nearest dollar). Sort by above_avg_by descending. Derived tables are a Google interview staple — they test whether you can decompose a problem into layers, which is exactly what Google expects of L5+ analyst candidates.
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Schema
employees
| emp_id | name | department | position | salary | hire_date | manager_id | performance_rating |
|---|---|---|---|---|---|---|---|
| 1 | Alice Johnson | Engineering | Senior Developer | 95000 | 2019-03-15 | 5 | 4.5 |
| 2 | Bob Smith | Engineering | Developer | 75000 | 2020-06-01 | 1 | 3.8 |
| 3 | Carol Williams | Marketing | Marketing Manager | 85000 | 2018-09-20 | NULL | 4.2 |
Expected output: Alice | Engineering | 95000 | 80000 | 15000
Hint
Concepts
SELECT Subquery JOIN Aggregation GROUP BY Subquery in FROM
Practise the topic: SQL practice questions · CTE practice · JOIN practice · GROUP BY exercises
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