SQL Quest › SQL Interview Questions › Aggregation & Grouping
Performance vs Salary Analysis
For each department, compare average salary of high performers (performance_rating >= 4.0) vs others (< 4.0). Show: department, headcount, high_performer_avg_salary, others_avg_salary, and performance_premium (difference, rounded to 0 dec). Sort by performance_premium descending.
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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: performance_premium: 20000
Hint
Concepts
SELECT GROUP BY CASE Aggregation ORDER BY Conditional Aggregation
Practise the topic: SQL practice questions · GROUP BY exercises · CASE WHEN practice
In these company practice sets
A SQL Quest challenge matched to patterns reported for these companies — not a question any of them has published.
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