hardPerformanceNext.js

The connection exhaustion

A developer asked an AI assistant to add a database query to a Next.js API route. The suggested code works fine in local testing, but under real traffic the app starts throwing 'too many connections' errors and the database eventually stops responding.

route.ts

import { Client } from 'pg';

export async function GET(request: Request) {
  const client = new Client({ connectionString: process.env.DATABASE_URL });
  await client.connect();
  const result = await client.query('SELECT * FROM products LIMIT 20');
  return Response.json(result.rows);
}

Why does this route work fine in local testing but crash the database under real traffic?

A new client connects to the database on every request and is never explicitly closed or reused — under concurrent traffic this quickly exhausts the database's max connection limit.

SELECT * always locks the entire products table until the request completes.

process.env.DATABASE_URL is re-read from disk on every request, adding latency but no connection issue.

Response.json() keeps the database connection open until the client's browser tab closes.