GROUP_ARRAY_MOVING_SUM

The GROUP_ARRAY_MOVING_SUM function calculates the moving sum of input values. The function can take the window size as a parameter. If left unspecified, the function takes the window size equal to the number of input values.

Syntax

GROUP_ARRAY_MOVING_SUM(<expr>)

GROUP_ARRAY_MOVING_SUM(<window_size>)(<expr>)

Arguments

Arguments	Description
<window_size>	Any numerical expression
<expr>	Any numerical expression

Return Type

Returns an Array with elements that are of the same type as the original data.

Examples

-- Create a table and insert sample data
CREATE TABLE hits (
  user_id INT,
  request_num INT
);

INSERT INTO hits (user_id, request_num)
VALUES (1, 10),
       (2, 15),
       (3, 20),
       (1, 13),
       (2, 21),
       (3, 25),
       (1, 30),
       (2, 41),
       (3, 45);

SELECT user_id, GROUP_ARRAY_MOVING_SUM(2)(request_num) AS request_num
FROM hits
GROUP BY user_id;

| user_id | request_num |
|---------|-------------|
|       1 | [10,23,43]  |
|       2 | [20,45,70]  |
|       3 | [15,36,62]  |