Why does the ROW_NUMBER() window function produce different results than RANK() when there are ties in the ordering column?

hard📝 Conceptual Q10 of 15

PostgreSQL - Window Functions in PostgreSQL

Why does the ROW_NUMBER() window function produce different results than RANK() when there are ties in the ordering column?

AROW_NUMBER() counts rows per partition; RANK() counts total rows

BROW_NUMBER() assigns unique sequential numbers ignoring ties; RANK() assigns same rank to ties and skips ranks after

CROW_NUMBER() cannot be used with ORDER BY; RANK() requires ORDER BY

DROW_NUMBER() groups tied rows together; RANK() always assigns unique numbers

Step-by-Step Solution

Solution:

Step 1: Understand ROW_NUMBER() behavior with ties
ROW_NUMBER() assigns a unique sequential number to each row, ignoring ties, so tied rows get different numbers.
Step 2: Understand RANK() behavior with ties
RANK() assigns the same rank to tied rows and skips subsequent ranks accordingly, causing gaps.
Final Answer:
ROW_NUMBER() assigns unique sequential numbers ignoring ties; RANK() assigns same rank to ties and skips ranks after -> Option B
Quick Check:
ROW_NUMBER() unique; RANK() ties share rank with gaps [OK]

Quick Trick: ROW_NUMBER() unique; RANK() ties share rank with gaps [OK]

Common Mistakes:

Master "Window Functions in PostgreSQL" in PostgreSQL

9 interactive learning modes - each teaches the same concept differently

Want More Practice?

15+ quiz questions · All difficulty levels · Free