n-1

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

ActiveRecord query optimization and N+1 prevention

ruby rails activerecord

by Sarah Mitchell 3 tabs

ruby

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

Rails N+1 query detection with Bullet

rails performance n-1

by Maya Patel 3 tabs