https://github.com/rails/rails/pull/35987

dirty_tracking_benchmark2.rb

# frozen_string_literal: true

require "bundler/inline"

gemfile(true) do
  source "https://rubygems.org"

  git_source(:github) { |repo| "https://github.com/#{repo}.git" }

  gem "rails", github: "rails/rails"
  gem "sqlite3"
  gem "benchmark-ips"
end

require "active_record"
require "logger"

ActiveRecord::Base.establish_connection(adapter: "sqlite3", database: ":memory:")
ActiveRecord::Base.logger = Logger.new(STDOUT)

ActiveRecord::Schema.define do
  create_table :users, force: true do |t|
    t.string :name
    t.timestamps null: false
  end
end

class User < ActiveRecord::Base
end

user = User.create!(name: "user name")

Benchmark.ips do |x|
  x.report("user.id") { user.id }
  x.report("user['id']") { user['id'] }
  x.report("user.name") { user.name }
  x.report("user['name']") { user['name'] }
  x.report("user.changed?") { user.changed? }
  x.report("user.saved_changes?") { user.saved_changes? }
end