gistfile1.txt

## Controller
def stats
  @visits = Visit.all
end

## View that produces 2 sql hits
<%= @visits[0] %>
<% @visits.each do |v| %>
  ...
<% end %>
#produces 2 sql hits
(0.000052) SELECT `id`, `user_id`, `created_at`, `updated_at` FROM `visits` WHERE `created_at` > '2009-10-15 00:00:00' ORDER BY `created_at` DESC LIMIT 1
(0.000036) SELECT `id`, `user_id`, `created_at`, `updated_at` FROM `visits` WHERE `created_at` > '2009-10-15 00:00:00' ORDER BY `created_at` DESC


## View that produces 1 sql hit
<% @visits.each do |v| %>
  ...
<% end %>
<%= @visits[0] %>
#produces
(0.000036) SELECT `id`, `user_id`, `created_at`, `updated_at` FROM `visits` WHERE `created_at` > '2009-10-15 00:00:00' ORDER BY `created_at` DESC

If you don't call @visits first it forces a separate query for @visits[0]