我有一点轨道问题，我无法弄明白 .

在本地我使用Mongrel运行rails 3.1和ruby 1.9.3，在 生产环境 我正在运行Passanger / Apache2 . 虽然在本地运行，但在开发环境中，我的数据库查询大约需要40到50秒，这是很重要的 . 我们在产品表中有大约15,000条记录，在游戏室中有5,000条记录，在collection_items中有1,700条记录，似乎rails正在针对这些整个表进行选择，这导致了减速 .

这是我的模型结构的概述：

Collection

  • has_many CollectionItems

CollectionItem

  • belongs_to Collection
  • has_many产品
  • has_many游戏室

Product

  • has_many LineItems
  • belongs_to ProductType
  • belongs_to CollectionItem

Cart

  • has_many LineItems

LineItem

  • belongs_to产品
  • belongs_to订单
  • belongs_to购物车

Here's my log:

Processing by CartController#index as HTML
Cart Load (0.7ms)  SELECT `carts`.* FROM `carts` WHERE `carts`.`id` = 7 LIMIT 1
CollectionGroup Load (1.6ms)  SELECT `collection_groups`.* FROM `collection_groups` WHERE (status = 'live')
Rendered cart/_checkout_steps.html.erb (1.2ms)
(0.4ms)  SELECT COUNT(*) FROM `line_items` WHERE `line_items`.`cart_id` = 7
LineItem Load (2.0ms)  SELECT `line_items`.* FROM `line_items` WHERE `line_items`.`cart_id` = 7
Product Load (33592.3ms)  SELECT `products`.* FROM `products` 
Product Load (1.8ms)  SELECT `products`.* FROM `products` WHERE `products`.`id` = 1 LIMIT 1
ProductType Load (181.5ms)  SELECT `product_types`.* FROM `product_types` 
[paperclip] Duplicate URL for image with /system/:attachment/:id/:style/:filename. This will clash with attachment defined in CollectionItem class
ProductType Load (1.5ms)  SELECT `product_types`.* FROM `product_types` WHERE `product_types`.`id` = 1 LIMIT 1
CollectionItem Load (**4701.0ms**)  SELECT `collection_items`.* FROM `collection_items` 
[paperclip] Duplicate URL for image with /system/:attachment/:id/:style/:filename. This will clash with attachment defined in ProductType class
Collection Load (157.8ms)  SELECT `collections`.* FROM `collections` 
Playroom Load (18056.7ms)  SELECT `playrooms`.* FROM `playrooms` 
CollectionItem Load (1.0ms)  SELECT `collection_items`.* FROM `collection_items` WHERE `collection_items`.`id` = 1 LIMIT 1
Product Load (1.0ms)  SELECT `products`.* FROM `products` WHERE `products`.`id` = 527 LIMIT 1
ProductType Load (1.0ms)  SELECT `product_types`.* FROM `product_types` WHERE `product_types`.`id` = 5 LIMIT 1
CollectionItem Load (0.8ms)  SELECT `collection_items`.* FROM `collection_items` WHERE `collection_items`.`id` = 31 LIMIT 1
Product Load (0.8ms)  SELECT `products`.* FROM `products` WHERE `products`.`id` = 11 LIMIT 1
ProductType Load (0.7ms)  SELECT `product_types`.* FROM `product_types` WHERE `product_types`.`id` = 2 LIMIT 1
CollectionItem Load (1.1ms)  SELECT `collection_items`.* FROM `collection_items` WHERE `collection_items`.`id` = 2 LIMIT 1
Product Load (1.0ms)  SELECT `products`.* FROM `products` WHERE `products`.`id` = 2 LIMIT 1
CACHE (0.0ms)  SELECT `product_types`.* FROM `product_types` WHERE `product_types`.`id` = 1 LIMIT 1
CACHE (0.0ms)  SELECT `collection_items`.* FROM `collection_items` WHERE `collection_items`.`id` = 1 LIMIT 1

The block of code which produces this is like this:

<% @cart.line_items.each do |line_item| %>
line_item.product.product_type.title

虽然整个网站都出现了这个问题，但我认为这与我们 Build 关系的方式有关 . 我无法弄清楚为什么Rails试图选择产品，游戏室和collection_items的完整表格（这需要45秒）

另外，我们在外键上设置了索引 .

任何想法或建议将不胜感激 .

mysql ruby-on-rails ruby-on-rails-3