Rails Algolia: Create subindex but without main index.

contact.rb

class Contact < ApplicationRecord

  include AlgoliaSearch

  algoliasearch per_environment: true, if: :turn_off_main_index do

    add_index "CONTACT_subset", if: :subset? do
      attributes :name, :email, :company, :state

      searchableAttributes ['name', 'company', 'unordered(email)']
      attributesForFaceting ['company', 'state']
    end

  end

  def turn_off_main_index
    false
  end

  def subset?
    ['CA', 'IL'].include?(state)
  end

end