PERCENT_RANK

Calculates the relative rank of each row as a percentage. Returns values between 0 and 1, where 0 represents the lowest rank and 1 represents the highest rank.

See also: CUME_DIST

Syntax

PERCENT_RANK()
OVER (
    [ PARTITION BY partition_expression ]
    ORDER BY sort_expression [ ASC | DESC ]
)

Arguments:

• PARTITION BY: Optional. Divides rows into partitions
• ORDER BY: Required. Determines the ranking order
• ASC | DESC: Optional. Sort direction (default: ASC)

Notes:

• Returns values between 0 and 1 (inclusive)
• First row always has PERCENT_RANK of 0
• Last row always has PERCENT_RANK of 1
• Formula: (rank - 1) / (total_rows - 1)
• Multiply by 100 to get percentile values

Examples

-- Create sample data
CREATE TABLE scores (
    student VARCHAR(20),
    score INT
);

INSERT INTO scores VALUES
    ('Alice', 95),
    ('Bob', 87),
    ('Charlie', 87),
    ('David', 82),
    ('Eve', 78);

Calculate percent rank (showing percentile position):

SELECT student, score,
       PERCENT_RANK() OVER (ORDER BY score DESC) AS percent_rank,
       ROUND(PERCENT_RANK() OVER (ORDER BY score DESC) * 100) AS percentile
FROM scores
ORDER BY score DESC, student;

Result:

student | score | percent_rank | percentile
--------+-------+--------------+-----------
Alice   |    95 |          0.0 |          0
Bob     |    87 |         0.25 |         25
Charlie |    87 |         0.25 |         25
David   |    82 |         0.75 |         75
Eve     |    78 |          1.0 |        100