Keyword to retrieve maximum value?
Interviewer Expectations for this Question
01
Core Competency
Assesses fundamental understanding of SQL & Databases conventions, runtime behavior, and memory/performance considerations.
02
Evaluation Criteria
Hiring managers look for precision, avoidance of ambiguous jargon, and ability to explain trade-offs under real production conditions.
Comprehensive Model Answer
Verified Solution
The keyword and aggregate function used to retrieve the maximum value of a column is MAX():
SELECT MAX(salary) AS highest_salary
FROM employees;
### With Grouping:
SELECT department_id, MAX(salary) AS top_dept_salary
FROM employees
GROUP BY department_id;
If an index exists on the target column, the database engine can find MAX() in $O(1)$ time by reading the last entry of the B-tree index.
Candidate Response Strategy & Interview Tips
- Start with a concise one-sentence summary: Deliver a direct, confident answer first before expanding into nuances.
- Demonstrate real-world trade-offs: Discuss where this approach excels and when you would avoid it in production systems.
- Discuss complexity & edge cases: Proactively explain time/space complexity or boundary conditions (null values, scale limits).
- Prepare for interviewer follow-ups: Technical hiring panels frequently probe deeper into concurrency, backward compatibility, or alternative libraries.