RETENTION (Lakehouse v1)

Aggregate function

The RETENTION() function takes as arguments a set of conditions from 1 to 32 arguments of type UInt8 that indicate whether a certain condition was met for the event.

Any condition can be specified as an argument (as in WHERE).

The conditions, except the first, apply in pairs: the result of the second will be true if the first and second are true, of the third if the first and third are true, etc.

Analyze Syntax

func.retention(<cond1> , <cond2> , ..., <cond32>)

Analyze Examples

table.user_id, func.retention(table.event_type=='signup', table.event_type='login', table.event_type='purchase').alias('sales_amounts')

| user_id | retention |
|---------|-----------|
|   1     | [1, 1, 0] |
|   2     | [1, 0, 1] |
|   3     | [1, 1, 0] |

SQL Syntax

RETENTION( <cond1> , <cond2> , ..., <cond32> );

Arguments

Arguments	Description
<cond>	An expression that returns a Boolean result

Return Type

The array of 1 or 0.

SQL Examples

Create a Table and Insert Sample Data

CREATE TABLE user_events (
  id INT,
  user_id INT,
  event_date DATE,
  event_type VARCHAR
);

INSERT INTO user_events (id, user_id, event_date, event_type)
VALUES (1, 1, '2022-01-01', 'signup'),
       (2, 1, '2022-01-02', 'login'),
       (3, 2, '2022-01-01', 'signup'),
       (4, 2, '2022-01-03', 'purchase'),
       (5, 3, '2022-01-01', 'signup'),
       (6, 3, '2022-01-02', 'login');

Query Demo: Calculate User Retention Based on Signup, Login, and Purchase Events

SELECT
  user_id,
  RETENTION(event_type = 'signup', event_type = 'login', event_type = 'purchase') AS retention
FROM user_events
GROUP BY user_id;

Result

| user_id | retention |
|---------|-----------|
|   1     | [1, 1, 0] |
|   2     | [1, 0, 1] |
|   3     | [1, 1, 0] |