performance

<article class="post">
  <h1><%= @post.title %></h1>
  <%= simple_format @post.body %>

  <!-- Lazy load comments when scrolled into view -->
  <%= turbo_frame_tag "post_#{@post.id}_comments",

module Keysettable
  extend ActiveSupport::Concern

  included do
    scope :keyset_page, ->(after: nil, limit: 20) do
      relation = order(created_at: :asc, id: :asc).limit(limit + 1)

import com.github.benmanes.caffeine.cache.CacheLoader;
import com.github.benmanes.caffeine.cache.Caffeine;
import com.github.benmanes.caffeine.cache.LoadingCache;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

module Cacheable
  extend ActiveSupport::Concern

  def cache_query(prefix, scope, expires_in: 15.minutes)
    key = [prefix, cache_version_token(scope)].join("/")

-- Create materialized view
CREATE MATERIALIZED VIEW user_statistics AS
SELECT
  users.id,
  users.username,
  COUNT(DISTINCT orders.id) AS order_count,

import functools
import threading


def debounce(wait):
    def decorator(func):

import { createHash } from "crypto";
import { Request, Response } from "express";

export function computeEtag(body: string): string {
  const digest = createHash("sha1").update(body).digest("base64");
  return `"${digest}"`;

package export

import (
	"encoding/csv"
	"log"
	"net/http"

-- Connection statistics
SELECT
  count(*) AS total_connections,
  count(*) FILTER (WHERE state = 'active') AS active,
  count(*) FILTER (WHERE state = 'idle') AS idle,
  count(*) FILTER (WHERE state = 'idle in transaction') AS idle_in_tx,

import { Suspense } from 'react'
import { useSuspenseQuery } from '@tanstack/react-query'
import { useParams } from 'react-router-dom'
import api from '@/services/api'
import { Post } from '@/types'
import { ErrorBoundary } from '@/components/ErrorBoundary'

import React, { lazy, Suspense, useState, useEffect } from 'react';

// 1. Component lazy loading
const HeavyComponent = lazy(() => import('./HeavyComponent'));
const AdminPanel = lazy(() => import('./AdminPanel'));
const Dashboard = lazy(() => import('./Dashboard'));

-- Basic EXPLAIN
EXPLAIN
SELECT * FROM users WHERE email = 'alice@example.com';

-- EXPLAIN with cost and row estimates
-- Output shows: Seq Scan on users (cost=0.00..15.50 rows=1 width=100)