/**
 * Interface to PostgreSQL client
 * */
const config = require('../config');
const pg = require('pg');
const knex = require('knex');

// remember: all values returned from the server are either NULL or a string
pg.types.setTypeParser(20, val => (val === null ? null : parseInt(val, 10)));
console.log('connecting %s', config.POSTGRES_URL);
const db = knex({
  client: 'pg',
  connection: config.POSTGRES_URL,
  pool: {
    afterCreate: (conn, done) => {
      // Set the minimum similarity for pg_trgm
      conn.query('SELECT set_limit(0.51);', (err) => {
        // if err is not falsy, connection is discarded from pool
        done(err, conn);
      });
    },
  },
});
db.on('query-error', (err) => {
  throw err;
});
module.exports = db;

/**
 * Interface to PostgreSQL client
 * */
const config = require('../config');
const pg = require('pg');
const knex = require('knex');

// remember: all values returned from the server are either NULL or a string
pg.types.setTypeParser(20, val => (val === null ? null : parseInt(val, 10)));
console.log('connecting %s', config.POSTGRES_URL);
const db = knex({
  client: 'pg',
  connection: config.POSTGRES_URL,
  pool: {
    afterCreate: (conn, done) => {
      // Set the minimum similarity for pg_trgm
      conn.query('SELECT set_limit(0.7);', (err) => {
        // if err is not falsy, connection is discarded from pool
        done(err, conn);
      });
    },
  },
});
db.on('query-error', (err) => {
  throw err;
});
module.exports = db;

Update db.js