PERCENTILE_ARRAY

Description

The PERCENTILE_ARRAY function calculates exact percentile arrays, allowing multiple percentile values to be computed at once. This function is primarily suitable for small datasets.

Key features:

1. Exact Calculation: Provides exact percentile results rather than approximations
2. Batch Processing: Can calculate multiple percentiles in a single operation
3. Scope: Best suited for handling small-scale datasets

Syntax

PERCENTILE_ARRAY(<col>, <array_p>)

Parameters

Parameter	Description
<col>	The column to calculate the percentile for
<array_p>	Percentile array, each element must be in the range [0.0, 1.0], e.g., [0.5, 0.95, 0.99]

Return Value

Return a DOUBLE type array, containing the calculated percentile values.

Examples

-- Create sample table
CREATE TABLE sales_data (
    id INT,
    amount DECIMAL(10, 2)
) DUPLICATE KEY(`id`)
DISTRIBUTED BY HASH(`id`) BUCKETS AUTO
PROPERTIES (
    "replication_allocation" = "tag.location.default: 1"
);

-- Insert sample data
INSERT INTO sales_data VALUES
(1, 10.5),
(2, 15.2),
(3, 20.1),
(4, 25.8),
(5, 30.3),
(6, 35.7),
(7, 40.2),
(8, 45.9),
(9, 50.4),
(10, 100.6);

-- Calculate multiple percentiles
SELECT percentile_array(amount, [0.25, 0.5, 0.75, 0.9]) as percentiles
FROM sales_data;

+-----------------------------------------+
| percentiles                             |
+-----------------------------------------+
| [21.25, 32.5, 43.75, 54.99999999999998] |
+-----------------------------------------+