optimization

# BAD: N+1 query problem
@users = User.all
@users.each do |user|
  puts user.posts.count  # Fires query for each user!
end

-- EXPLAIN ANALYZE (actual execution statistics)
EXPLAIN ANALYZE
SELECT u.username, COUNT(o.id) AS order_count
FROM users u
LEFT JOIN orders o ON u.id = o.user_id
WHERE u.created_at >= '2024-01-01'

package com.example.myapp.utils

import android.os.Build
import android.os.StrictMode
import android.os.Trace
import timber.log.Timber

use std::borrow::Cow;

fn ensure_prefix(input: &str) -> Cow<str> {
    if input.starts_with("https://") {
        Cow::Borrowed(input)
    } else {

Rails.application.configure do
  # Bullet configuration
  config.after_initialize do
    Bullet.enable = true
    Bullet.alert = true # Show JavaScript alert
    Bullet.bullet_logger = true # Log to bullet.log

// Creating elements
const div = document.createElement('div');
div.id = 'container';
div.className = 'box rounded';
div.textContent = 'Hello World';

-- SCHEMA DESIGN CHECKLIST

-- 1. Use appropriate data types
CREATE TABLE users_optimized (
  id SERIAL PRIMARY KEY,               -- Auto-increment
  uuid UUID DEFAULT gen_random_uuid(), -- UUID for external IDs

# Gemfile
group :development do
  gem 'rack-mini-profiler'
  gem 'memory_profiler'
  gem 'stackprof'  # For flamegraphs
  gem 'bullet'     # N+1 detection

# Optimized production Dockerfile

# Stage 1: Dependencies
FROM node:20-alpine AS deps
WORKDIR /app

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

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'));

-- Create basic index
CREATE INDEX idx_users_email ON users(email);

-- Unique index (enforces uniqueness)
CREATE UNIQUE INDEX idx_users_username ON users(username);