node.jspostgresqlnode-postgresnode-pg-pool

Reusing pg-pool via module exports

After reading the docs: https://github.com/brianc/node-pg-pool, I am slightly concerned about reusing the new Pool() method.

The docs suggests that I need to place the new Pool() before exports and return it like so 

// db.js
const pool = new Pool();
module.exports = () => { return pool; }

This way I can reuse Pool until the idleTimeoutMillis or client.release(), by using require() from other files Eg: 

const connect = require('./db')
connect().query(' .... ');

If this is correct, how does it work? Does node.js caches the new Pool(), as it not inside module.exports?

Solution

  • Yes, it is effectively cached since you create it exactly once (and node caches modules) and you always refer to that same instance in your exported method.