How to insert million records via nodejs at maximum speed via pipe

index.js

const knex = require('knex')(knexConfig)
const csv = require('csv-parser')
const Transform = require('stream').Transform;
var fs = require('fs');

function importData(knex, Promise) {
  return new Promise(function (resolve, reject){
    fs.createReadStream('some-csv-file.csv')
      .on('error', reject)
      .pipe(csv())
      .on('error', reject)
      .pipe(new Transform({
         objectMode: true,
         transform: function (chunk, _, next) {
             knex(tableName).insert(chunk).then(function () {
                next();
             }, next);
       }, function (done) {
          resolve();
          done();
        })).on('error', reject);
     }));
   });
});