codesnips

eager-loading

ruby 
class PostsController < ApplicationController
  def index
    posts = Post.for_feed.page(params[:page]).per(25)

    render json: {
      data: posts.map { |post| PostSerializer.new(post).as_json },

N+1 Proof Serialization with preloaded associations

rails activerecord performance
by codesnips 3 tabs
ruby 
class ArticlesController < ApplicationController
  def index
    # Bounded queries: without preload, article.author in the view raises.
    @articles = Article
      .published
      .preload(:author, :tags)

Strict Loading to Catch N+1 in Development

rails activerecord performance
by codesnips 4 tabs