Rails 排序或排序查询很慢

Question

使用 Rails 3.2、Ruby 1.9、will_paginate。我有 100,000 条记录，并测试了以下查询：

# 1000+ms to load
@shops = Shop.where(:shop_type => @type).paginate(:include => :photos, :page => params[:page], :per_page => 25, :order => 'created_at DESC')

# 1000+ms to load
@shops = Shop.paginate(:include => :photos, :page => params[:page], :per_page => 25, :order => 'created_at DESC')

# 1000+ms to load
@shops = Shop.order('created_at DESC').limit(25)

# 1+ms to load
@shops = Shop.paginate(:include => :photos, :page => params[:page], :per_page => 25)

我注意到这个order选项非常慢。测试结果表明这will_paginate不是问题。

order我应该如何更改它以便可以加快查询速度。

Answer 1

是的，尝试在订单列上创建索引。它会加快速度。