parallelity of queries (multiple queries at once)?

I wrote a program, which requests n-queries (for instance 20,000) at once to my postgres database.

When I do this with several clients who want to query 20,000 at once too, there is no parallelity. That means, the requests of the second client will be queued until the first client finished all his queries.

Is this a normal behavior for postgres? If yes, how can I prevent that one user gets all the ressources (and the others have to wait) if there is no parallelity?

This is my code:

const express = require('express');
const app = express();
const { Pool } = require("pg");
const pool = new Pool();


benchmark(){
    pool.connect((err, client, done) => {
      if (err) throw err;
      client.query("SELECT * from member where m_id = $1", [1], (err, res) => {
        done();
        if (err) {
          console.log(err.stack);
        } else {
          console.log(res.rows[0]);
        }
      });
    }); 
}


app.get('/', function(req, res) {
  for(let i=0;i<20000;i++){
    benchmark();
  }
});

[ghost]

Thank you for your replies you were very helpful!

[charmander]

Pool doesn’t use pg.defaults. Pass options:

const pool = new pg.Pool({ max: 20 });

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