countResample

Example of using the Resample combinator with count

Description

The Resample combinator can be applied to the count aggregate function to count values of a specified key column in a fixed number of intervals (N).

Example usage

Basic example

Let’s look at an example. We’ll create a table which contains the name, age and wage of employees, and we’ll insert some data into it:

CREATE TABLE employee_data 
(
    name String,
    age UInt8,
    wage Float32
) 
ENGINE = MergeTree()
ORDER BY tuple()

INSERT INTO employee_data (name, age, wage) VALUES
    ('John', 16, 10.0),
    ('Alice', 30, 15.0),
    ('Mary', 35, 8.0),
    ('Evelyn', 48, 11.5),
    ('David', 62, 9.9),
    ('Brian', 60, 16.0);

Let’s count all the people whose age lies in the intervals of [30,60) and [60,75). Since we use integer representation for age, we get ages in the [30, 59] and [60,74] intervals. To do so we apply the Resample combinator to count

SELECT countResample(30, 75, 30)(name, age) AS amount FROM employee_data

┌─amount─┐
│ [3,2]  │
└────────┘

See also

• count
• Resample combinator