Mass update counter cache columns (with Rails references)

migration.rb

class UpdateCounters < ActiveRecord::Migration
  def up
    say_with_time 'Updating counter_cache_column for ModelWithColumn' do
      ActiveRecord::Base.connection.execute <<-SQL
        UPDATE model_with_column
        SET counter_cache_column = (
          SELECT COUNT(*)
          FROM model_with_counter_cache
          WHERE model_with_counter_cache.reference = model_with_column.id
        )
      SQL
    end
  end
end

update_counters.sql

UPDATE model_with_column
SET counter_cache_column = (
  SELECT COUNT(*)
  FROM model_with_counter_cache
  WHERE model_with_counter_cache.reference = model_with_column.id
)