[Solved] Given the table employees with columns department and salary, what will this query return?SELECT department, salary, RANK() OVER (PARTITION BY department ORDER BY salary DESC) AS rank FROM employees; | PostgreSQL

PostgreSQL - Window Functions in PostgreSQL

Given the table employees with columns department and salary, what will this query return?

SELECT department, salary, RANK() OVER (PARTITION BY department ORDER BY salary DESC) AS rank FROM employees;

ARanks employees within each department by salary, highest salary gets rank 1.

BRanks all employees together ignoring department, highest salary gets rank 1.

CCalculates total salary per department.

DReturns an error because RANK() cannot be used with PARTITION BY.

Step-by-Step Solution

Solution:

Step 1: Understand RANK() with PARTITION BY
RANK() assigns ranks within each partition (department) ordered by salary descending.
Step 2: Analyze query output
Each employee gets a rank starting at 1 for highest salary in their department, ties get same rank.
Final Answer:
Ranks employees within each department by salary, highest salary gets rank 1. -> Option A
Quick Check:
RANK() with PARTITION BY ranks within groups [OK]

Quick Trick: RANK() with PARTITION BY ranks within groups [OK]

Common Mistakes:

Master "Window Functions in PostgreSQL" in PostgreSQL

9 interactive learning modes - each teaches the same concept differently

Given the table employees with columns department and salary, what will this query return?