count

# File activerecord/lib/active_record/internal_metadata.rb, line 65
    def count
      sm = Arel::SelectManager.new(arel_table)
      sm.project(*Arel::Nodes::Count.new([Arel.star]))

      @pool.with_connection do |connection|
        connection.select_values(sm, "#{self.class} Count").first
      end
    end