counter_cache - count how many children a records has

Models:
-------
1)
user.rb
has_many :recipes

2)
recipe.rb # add counter_cache: true to recalculate posts_count field in user table
belongs_to :user, counter_cache: true

Migration:
---------
bin/rails g migration add_recipes_count_to_users recipes_count:integer

class AddRecipesCountToUsers < ActiveRecord::Migration[6.1]
  def change
    add_column :users, :recipes_count, :integer, default: 0, null: false
  end
end

bin/rails db:migrate

Update to reset counter:
------------------------
rails c - recalculate recipes_count for all existing posts and users

User.find_each { |user| User.reset_counters user.id, :recipes }

On/Off in Dev mode
-------------------
bin/rails dev:cache