The Ultimate Guide to High Availability with MariaDB

PERCENTILE_CONT

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MariaDB starting with 10.3.3

The PERCENTILE_CONT() window function was first introduced with in MariaDB 10.3.3.

Contents

  1. Syntax
  2. Description
  3. Examples
  4. See Also

Syntax

As an ordered set aggregate function:

<<code>>
<</code>>

Description

PERCENTILE_CONT() is an ordered set aggregate function which can also be used as a window function.

Examples

CREATE TABLE book_rating (name CHAR(30), star_rating TINYINT);

INSERT INTO book_rating VALUES ('Lord of the Ladybirds', 5);
INSERT INTO book_rating VALUES ('Lord of the Ladybirds', 3);
INSERT INTO book_rating VALUES ('Lady of the Flies', 1);
INSERT INTO book_rating VALUES ('Lady of the Flies', 2);
INSERT INTO book_rating VALUES ('Lady of the Flies', 5);

SELECT name, PERCENTILE_CONT(0.5) WITHIN GROUP (ORDER BY star_rating) 
  OVER (PARTITION BY name) AS pc 
  FROM book_rating;
+-----------------------+--------------+
| name                  | pc           |
+-----------------------+--------------+
| Lord of the Ladybirds | 4.0000000000 |
| Lord of the Ladybirds | 4.0000000000 |
| Lady of the Flies     | 2.0000000000 |
| Lady of the Flies     | 2.0000000000 |
| Lady of the Flies     | 2.0000000000 |
+-----------------------+--------------+

SELECT name, PERCENTILE_CONT(1) WITHIN GROUP (ORDER BY star_rating) 
  OVER (PARTITION BY name) AS pc 
  FROM book_rating;
+-----------------------+--------------+
| name                  | pc           |
+-----------------------+--------------+
| Lord of the Ladybirds | 5.0000000000 |
| Lord of the Ladybirds | 5.0000000000 |
| Lady of the Flies     | 5.0000000000 |
| Lady of the Flies     | 5.0000000000 |
| Lady of the Flies     | 5.0000000000 |
+-----------------------+--------------+

SELECT name, PERCENTILE_CONT(0) WITHIN GROUP (ORDER BY star_rating) 
  OVER (PARTITION BY name) AS pc 
  FROM book_rating;
+-----------------------+--------------+
| name                  | pc           |
+-----------------------+--------------+
| Lord of the Ladybirds | 3.0000000000 |
| Lord of the Ladybirds | 3.0000000000 |
| Lady of the Flies     | 1.0000000000 |
| Lady of the Flies     | 1.0000000000 |
| Lady of the Flies     | 1.0000000000 |
+-----------------------+--------------+

See Also

  • MEDIAN - a special case of PERCENTILE_CONT equivalent to PERCENTILE_CONT(0.5)

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