fera_performance_snippet.rb

## We can leverage on eager loading using joins to load the plans with the subscription in one single query.

def index
  @subscriptions = Subscription.joins(:plan).order(created_at: :desc).page(params[:page]).per(100)
end

## As a sidenote, I would move the logic for the order into a scope in the Subscription model
## Something like this

class Subscription < ApplicationRecord
  scope :latest, -> { order(created_at: :desc) }
end

## In the controller
def index
  @subscriptions = Subscription.joins(:plan).latest.page(params[:page]).per(100)
end