GROUP_ARRAY_MOVING_AVG (Lakehouse v1)

The GROUP_ARRAY_MOVING_AVG function calculates the moving average 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.

Analyze Syntax

func.group_array_moving_avg(<expr1>)

Analyze Examples

table.user_id, func.group_array_moving_avg(table.request_num).alias('avg_request_num')

| user_id | avg_request_num  |
|---------|------------------|
|       1 | [5.0,11.5,21.5]  |
|       3 | [10.0,22.5,35.0] |
|       2 | [7.5,18.0,31.0]  |

SQL Syntax

GROUP_ARRAY_MOVING_AVG(<expr>)

GROUP_ARRAY_MOVING_AVG(<window_size>)(<expr>)

Arguments

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

Return Type

Returns an Array with elements of double or decimal depending on the source data type.

SQL 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_AVG(2)(request_num) AS avg_request_num
FROM hits
GROUP BY user_id;

| user_id | avg_request_num  |
|---------|------------------|
|       1 | [5.0,11.5,21.5]  |
|       3 | [10.0,22.5,35.0] |
|       2 | [7.5,18.0,31.0]  |