ClickHouse NodeJS UDF

This basic example illustrates a simple sum NodeJS powered Clickhouse UDF function

⏱️ Why

Clickhouse is super fast and already has all the functions one could dream. What is this for?

This example is designed to understand the underlying formats and unleash imagination for integrators.

NodeJS Function

Create an executable NodeJS script

• read input from stdin
• split row values by tabs
• return some output

In our example we'll just accept two integers and sum them

ClickHouse UDF

Configure a UDF Function to invoke your script

• use directory /var/lib/clickhouse/user-scripts to store user-scripts

Use UDF

SELECT node_sum(10, 20)

Query id: f98a5f83-4e94-41d0-9d9f-78b37d3af152

┌─node_sum(10, 20)-─┐
│                30 │
└───────────────────┘

1 rows in set. Elapsed: 0.054 sec.