RANK / DENSE_RANK

SELECT name, score,
       ROW_NUMBER() OVER (ORDER BY score DESC) AS row_num,
       RANK()       OVER (ORDER BY score DESC) AS rank,
       DENSE_RANK() OVER (ORDER BY score DESC) AS dense_rank
FROM   leaderboard;

-- Example output:
--   Alice   100   1   1   1
--   Bob      90   2   2   2
--   Carol    90   3   2   2     ← tied with Bob
--   Dave     80   4   4   3     ← rank skips 3, dense_rank doesn't
--   Eve      70   5   5   4

-- Per-category rank
SELECT product, category, price,
       RANK() OVER (PARTITION BY category ORDER BY price DESC) AS price_rank
FROM   products;